[
{
"id": "authors:py9e7-1dw32",
"collection": "authors",
"collection_id": "py9e7-1dw32",
"cite_using_url": "https://authors.library.caltech.edu/records/py9e7-1dw32",
"type": "article",
"title": "Scaling Relations of Galactic Outflows across Cosmic Time: New Insights from Cosmic Noon",
"author": [
{
"family_name": "Liou",
"given_name": "Tiffany"
},
{
"family_name": "Xu",
"given_name": "Xinfeng"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636"
},
{
"family_name": "Cuestas",
"given_name": "Nathalie A. Korhonen",
"orcid": "0000-0003-2385-9240"
},
{
"family_name": "Faucher-Gigu\u00e8re",
"given_name": "Claude-Andr\u00e9",
"orcid": "0000-0002-4900-6628"
},
{
"family_name": "Miller",
"given_name": "Tim B.",
"orcid": "0000-0001-8367-6265"
},
{
"family_name": "Rudie",
"given_name": "Gwen",
"orcid": "0000-0002-8459-5413"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395"
}
],
"abstract": "\n
Galactic outflows play a significant role in regulating galaxy evolution. Scaling relations between stellar mass (M\u22c6), star formation rate (SFR), and outflow properties have been extensively studied at low redshifts (z < 1) but less so beyond z ∼ 2. We construct a joint sample of 387 galaxies from z ∼ 0–9, including 98 new Cosmic Noon galaxies from the Keck Baryonic Structure Survey and the Keck Lyman Continuum Spectroscopic Survey. Using high signal-to-noise emission lines (SNR > 50 for Hα or [O iii] λ5007) from Keck/MOSFIRE spectra, we detect warm-ionized outflows by decomposing lines into narrow and broad components. With the joint sample, we explore the redshift evolution of outflow scaling relations. On average, outflows at Cosmic Noon have higher maximum velocities than those at low z by up to a factor of 3 for a fixed M\u22c6, SFR, or SFR surface density. They also have higher mass outflow rates for a fixed M\u22c6. Despite faster and stronger outflows, there is no evolution in the mass loading factor for a fixed M\u22c6. We find evidence for galactic fountains, as the majority of outflowing gas is recycled at a radius of ∼0.03 Rvir. We also constrain the overall outflow occurrence rate in our galaxy sample to at least 30% when taking galaxy orientation and outflow geometry into account. By analyzing the largest sample of warm-ionized outflows at Cosmic Noon to date and compiling large galaxy samples across all redshifts, we present a comprehensive analysis of galactic outflows throughout cosmic time.
\n
\n
We present the large-scale spatial Lyα profiles of galaxies from the Keck Baryonic Structure Survey (KBSS) at 2 < z < 3. This work also describes the Lyα imaging for the KBSS-Lyα survey for the first time. Our sample includes 548 Lyα-selected galaxies and 120 continuum-selected galaxies with Lyα narrowband imaging, and we measure the spatial morphology of Lyα and continuum emission for stacked subsamples of these two populations. These samples allow us to study the variation in Lyα emission profiles over a broad range of UV continuum luminosities and Lyα equivalent widths (EWLyα), including systems with net Lyα absorption in slit spectroscopy. We characterize the spatial profiles using two techniques: directly fitting an exponential function to the stacked profile, and a multicomponent forward-modeling technique using the empirical large-scale point-spread function. We find that both methods yield similar results and that the forward-modeling technique self-consistently fits profiles exhibiting central Lyα emission or Lyα absorption, with the spatial scale of central Lyα approximately matching that of the continuum emission. We also find extended Lyα emission such that all of our subsamples—including central Lyα absorbers—are net Lyα emitters on scales comparable to the circumgalactic medium (R \u2273 50 kpc, θ \u2273 6″). We find that the scale length of the Lyα halo is not strongly dependent on the properties of the central galaxy, including its net continuum luminosity or EWLyα; although, we find a possible weak tendency of continuum-faint, high-EWLyα galaxies to exhibit larger Lyα halos in contrast with previous work.
\n
\n
We present detections of auroral emission lines of [O iii], [O ii], [S iii], and [S ii] in deep JWST/NIRSpec spectroscopy for 41 star-forming galaxies at z = 1.4–7.2 from the AURORA survey. We combine these new observations with 98 star-forming galaxies at z = 1.3–10.6 with detected auroral lines drawn from the literature to form a sample of 139 high-redshift galaxies with robust electron temperature and direct-method oxygen abundance determinations. This sample notably covers a wider dynamic range in metallicity than previous work, spanning 0.02–0.9 Z\u2299. We calibrate empirical relations between 19 emission-line ratios and oxygen abundance, providing a robust tool set to infer accurate gas-phase metallicities of high-redshift galaxies when auroral lines are not detected. While calibrations based on lines of α elements (O, Ne, S, Ar) appear reliable, we find significant scatter in calibrations involving lines of N driven by a high dispersion in N/O at fixed O/H, suggesting that N-based line ratios are less reliable tracers of the oxygen abundance at high redshift. These new high-redshift calibrations are notably offset from those based on typical z ∼ 0 galaxy and H ii region samples, and are better matched by samples of extreme local galaxies that are analogs of high-redshift sources. The new metallicity calibrations presented in this work pave the way for robust studies of galaxy chemical evolution in the early Universe, leading to a better understanding of baryon cycling and galaxy formation from Cosmic Noon through the Epoch of Reionization.
\n
We present high-spatial-resolution (\u22721 .″0), multiwavelength observations of UGC 2369S, a nearby luminous infrared galaxy showing three distinct cores separated on kiloparsec scales in near-infrared (NIR) imaging with significant X-ray emission. Utilizing optical/NIR adaptive optics, radio, Chandra X-ray, as well as archival Hubble Space Telescope imaging, we perform a comprehensive study of active galactic nuclei (AGN) activity, obscuration, and host properties. As one of the clearest cases of a triple-nucleus merger at \u22433 kpc separations, UGC 2369S is the first to be studied with high-resolution observations at multiple wavelengths. We find that the northern core, having possibly the most massive black hole (BH) in the system (MBH \u2243 108 M\u2299), is consistent with a heavily obscured AGN. However, its high dust extinction (Av > 5), hydrogen column density (NH \u2273 1025 cm−2), and nondetection of optical coronal lines and coronal X-ray emission leave the identification inconclusive. The other two cores show no evidence for black-hole activity and instead exhibit signatures of tidal disruption. From stellar mass surface density and stellar velocity dispersion maps, we infer that the strongly varying gravitational potential in this three-body system may have cannibalized the stellar bulge of the southwestern core, leaving a metal-enriched remnant. An ongoing survey focusing on similar triple systems could help us understand how they evolve and help benchmark numerical simulations, providing insight into gravitational wave predictions and the formation of the most massive BHs.
",
"doi": "10.3847/1538-4357/ae5643",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2026-05-10",
"series_number": "2",
"volume": "1002",
"issue": "2",
"pages": "130"
},
{
"id": "authors:hkbas-p1525",
"collection": "authors",
"collection_id": "hkbas-p1525",
"cite_using_url": "https://authors.library.caltech.edu/records/hkbas-p1525",
"type": "article",
"title": "Nitrogen abundances in star-forming galaxies 2.2 Gyr after the Big Bang are not elevated",
"author": [
{
"family_name": "Schaerer",
"given_name": "D.",
"orcid": "0000-0001-7144-7182"
},
{
"family_name": "Izotov",
"given_name": "Y. I.",
"orcid": "0000-0002-1416-6082"
},
{
"family_name": "Marques-Chaves",
"given_name": "R.",
"orcid": "0000-0001-8442-1846"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "N.",
"orcid": "0000-0001-9687-4973"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855"
},
{
"family_name": "Mascia",
"given_name": "S.",
"orcid": "0000-0002-9572-7813"
},
{
"family_name": "Chisholm",
"given_name": "J.",
"orcid": "0000-0002-0302-2577"
},
{
"family_name": "Flury",
"given_name": "S. R.",
"orcid": "0000-0002-0159-2613"
},
{
"family_name": "Guseva",
"given_name": "N.",
"orcid": "0000-0002-7938-614X"
},
{
"family_name": "Heckman",
"given_name": "T."
},
{
"family_name": "Henry",
"given_name": "A.",
"orcid": "0000-0002-6586-4446"
},
{
"family_name": "Inoue",
"given_name": "A. K.",
"orcid": "0000-0002-7779-8677"
},
{
"family_name": "Jung",
"given_name": "I.",
"orcid": "0000-0003-1187-4240"
},
{
"family_name": "Kusakabe",
"given_name": "H.",
"orcid": "0000-0002-3801-434X"
},
{
"family_name": "Mawatari",
"given_name": "K.",
"orcid": "0000-0003-4985-0201"
},
{
"family_name": "Oesch",
"given_name": "P.",
"orcid": "0000-0001-5851-6649"
},
{
"family_name": "\u00d6stlin",
"given_name": "G.",
"orcid": "0000-0002-3005-1349"
},
{
"family_name": "Pentericci",
"given_name": "L.",
"orcid": "0000-0001-8940-6768"
},
{
"family_name": "Roy",
"given_name": "N.",
"orcid": "0000-0002-4430-8846"
},
{
"family_name": "Saldana-Lopez",
"given_name": "A.",
"orcid": "0000-0001-8419-3062"
},
{
"family_name": "Sato",
"given_name": "R."
},
{
"family_name": "Vanzella",
"given_name": "E.",
"orcid": "0000-0001-5228-9326"
},
{
"family_name": "Verhamme",
"given_name": "A.",
"orcid": "0000-0002-2201-1865"
},
{
"family_name": "Wang",
"given_name": "B.",
"orcid": "0000-0001-9269-5046"
}
],
"abstract": "Using deep, medium-resolution, JWST rest-optical spectra of a sample of typical star-forming galaxies (Lyman-break galaxies and Lyman-α emitters) from the LyC22 survey at z\u2004∼\u20043, we determined the nebular abundances of N, O, and Ne relative to H for a subsample of 25 objects with a direct method based on auroral [O\u202fIII] λ4363 line detections. Our measurements increased the number of accurate N/O determinations at z\u2004∼\u20042\u2005−\u20054 using a homogeneous approach. We found a mean value of log(N/O) = −+0.25−0.21 over a metallicity range of 12\u2005+\u2005log(O/H) = 7.56 to 8.44. The observed N/O ratio and scatter are indistinguishable from that observed in low-z galaxies and H\u202fII regions over the same metallicity range, thus showing no redshift evolution of N/O for typical galaxies over a significant fraction of cosmic time. We also show that typical z\u2004∼\u20043 galaxies have a similar offset in the BPT diagram to galaxies from the low-z Lyman Continuum Survey (LzLCS) when compared to the average of SDSS galaxies, and we demonstrate that this offset is not due to enhanced nitrogen abundances. Our results establish a basis for future studies of the evolution of N and O at higher redshifts.
",
"doi": "10.1051/0004-6361/202556832",
"issn": "0004-6361",
"publisher": "EDP Sciences",
"publication": "Astronomy & Astrophysics",
"publication_date": "2026-04",
"volume": "708",
"pages": "A242"
},
{
"id": "authors:8k7gd-qvq19",
"collection": "authors",
"collection_id": "8k7gd-qvq19",
"cite_using_url": "https://authors.library.caltech.edu/records/8k7gd-qvq19",
"type": "article",
"title": "Joint Optical and Infrared Observations of Nitrogen and Oxygen Reveal the Dust-obscured Gas in Haro 3",
"author": [
{
"family_name": "Chen \u9648",
"given_name": "Yuguang \u6631\u5149",
"orcid": "0000-0003-4520-5395"
},
{
"family_name": "Jones",
"given_name": "Tucker",
"orcid": "0000-0001-5860-3419"
},
{
"family_name": "Sanders",
"given_name": "Ryan L.",
"orcid": "0000-0003-4792-9119"
},
{
"family_name": "Fadda",
"given_name": "Dario",
"orcid": "0000-0002-3698-7076"
},
{
"family_name": "Sutter",
"given_name": "Jessica",
"orcid": "0000-0002-9183-8102"
},
{
"family_name": "Minchin",
"given_name": "Robert",
"orcid": "0000-0002-1261-6641"
},
{
"family_name": "Prusinski",
"given_name": "Nikolaus Z.",
"orcid": "0000-0001-5847-7934",
"clpid": "Prusinski-Nikolaus-Z"
},
{
"family_name": "Rhoades",
"given_name": "Sunny",
"orcid": "0009-0007-0184-8176"
},
{
"family_name": "GC",
"given_name": "Keerthi Vasan",
"orcid": "0000-0002-2645-679X"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Huntzinger",
"given_name": "Erin",
"orcid": "0009-0002-6927-5259"
},
{
"family_name": "Kelly",
"given_name": "Paige",
"orcid": "0009-0009-4213-3630"
},
{
"family_name": "Berg",
"given_name": "Danielle A.",
"orcid": "0000-0002-4153-053X"
},
{
"family_name": "Bresolin",
"given_name": "Fabio",
"orcid": "0000-0002-5068-9833"
},
{
"family_name": "Herrera-Camus",
"given_name": "Rodrigo",
"orcid": "0000-0002-2775-0595"
},
{
"family_name": "Rickards Vaught",
"given_name": "Ryan J.",
"orcid": "0000-0001-9719-4080"
},
{
"family_name": "Roberts-Borsani",
"given_name": "Guido",
"orcid": "0000-0002-4140-1367"
},
{
"family_name": "Senchyna",
"given_name": "Peter",
"orcid": "0000-0002-9132-6561"
},
{
"family_name": "Spilker",
"given_name": "Justin S.",
"orcid": "0000-0003-3256-5615"
},
{
"family_name": "Stark",
"given_name": "Daniel P.",
"orcid": "0000-0001-6106-5172"
},
{
"family_name": "Weiner",
"given_name": "Benjamin",
"orcid": "0000-0001-6065-7483"
},
{
"family_name": "Martin",
"given_name": "D. Christopher",
"orcid": "0000-0002-8650-1644",
"clpid": "Martin-D-Christopher"
},
{
"family_name": "Matuszewski",
"given_name": "Mateusz",
"orcid": "0000-0003-2821-1750",
"clpid": "Matuszewski-Mateusz"
},
{
"family_name": "McGurk",
"given_name": "Rosalie C.",
"orcid": "0000-0003-2064-4105"
},
{
"family_name": "Neill",
"given_name": "James D.",
"orcid": "0000-0002-0466-1119",
"clpid": "Neill-James-D"
}
],
"abstract": "\n
Accurate chemical compositions of star-forming regions provide a critical diagnostic tool for characterizing the star formation history and gas flows that regulate galaxy formation. However, the abundance discrepancy factor (ADF) between measurements derived from the “direct” optical electron temperature (Te) method and those from recombination lines (RLs) introduces a ∼0.2 dex systematic uncertainty in the oxygen abundance. The degree of uncertainty for other elements is unknown. We conduct a comprehensive analysis of O++ and N+ ion abundances using optical and far-infrared (far-IR) spectra of a star-forming region within the nearby dwarf galaxy Haro 3, which exhibits a typical ADF. Assuming homogeneous conditions, the far-IR emission indicates an oxygen abundance higher than that derived using the Te method and consistent with the RL value, as expected from temperature fluctuations, whereas the far-IR nitrogen abundance is too large to be explained by temperature fluctuations. A two-phase analytical model reveals that differential dust obscuration associated with temperature inhomogeneity is likely required to explain all the emission-line ratios, and that the total oxygen metallicity of two phases is consistent with the RL metallicity. Our findings underscore the critical importance of resolving the cause of abundance discrepancies and understanding the biases between different metallicity methods. This work presents a promising methodology, and we identify further approaches to address the dominant sources of uncertainty.
\n
\n
We present the nebular attenuation curves and dust covering fractions for 24 z = 1.5–4.4 star-forming galaxies using multiple Balmer and Paschen lines from the JWST/AURORA survey. Nebular reddening derived from Paschen lines exceeds that from Balmer lines for at least half the galaxies in the sample when assuming the commonly adopted Galactic extinction curve, implying the presence of heavily reddened star formation. The nebular attenuation curves exhibit a broad range of normalizations (RV \u2243 3.2–16.4). Motivated by the offsets in reddening deduced from the Balmer and Paschen lines, as well as the high RV values for the individual nebular attenuation curves, both of which suggest variations in the dust–star geometry, we propose a model with a sub-unity dust covering fraction (fcov). Fitting such a model to the H i recombination line ratios indicates fcov ∼ 0.6–1.0. The normalizations of the nebular attenuation curves, RV, are driven primarily by fcov and the mix of reddened and unreddened OB associations. Thus, the diversity of nebular attenuation curves can be accommodated by assuming dust grain properties similar to that of Milky Way sightlines but with a sub-unity covering fraction of dust. Integrated measurements of multiple Balmer and Paschen lines can be used to place novel constraints on the dust covering fraction towards OB associations. These, in turn, provide new avenues for exploring the role of the dust and gas covering fractions in a number of relevant aspects of high-redshift galaxies, including the impact of stellar feedback on ISM porosity and the escape of Lyα and Lyman continuum radiation.
\n
\n
Galaxies at Cosmic Noon (z ∼ 2–3) are characterized by rapid star formation that will lead to significant metal enrichment in the interstellar medium (ISM). While much observational evidence suggests that these galaxies are chemically distinct from those in the local Universe, directly measuring the ISM chemistry in large samples of high-z galaxies is only now possible with the observational capabilities of JWST. In this first key paper of the CECILIA program, we present the direct-method physical conditions and multielement abundances in 20 galaxies at Cosmic Noon. Using a combination of archival Keck/MOSFIRE and new ∼30 hr NIRSpec spectroscopy, we measure multiple electron gas densities and the temperature structure from the O+ and S2+ ions. We find that ne[O ii] and ne[S ii] are comparable but elevated with respect to ne in local star-forming galaxies, and the simultaneous Te[O ii] and Te[S iii] generally agree with photoionization model Te scaling relations. The O abundances in the CECILIA galaxies range from 12 + log(O/H) = 7.76 to 8.81 (12%–131% solar O/H), representing some of the highest direct-method metallicities and lowest Te (Te[O ii] ≈ 6500 K) measured with JWST to date. The CECILIA galaxies exhibit significantly subsolar S/O and Ar/O, a signature of predominant enrichment from core-collapse supernovae. The N/O–O/H trends in the CECILIA galaxies generally agree with the abundance trends in local nebulae, but the large scatter in N/O could be sensitive to the star formation history. The CECILIA observations demonstrate that exceptionally deep JWST spectroscopy can unveil the multielement ISM abundance patterns in typical high-z galaxies.
\n
We investigate galaxy populations in the HS1700+64 protocluster at z = 2.30, characterized by two prominent linear filaments traced by spatially extended Lyα blobs. We conducted a wide area mapping of emission line galaxies across the protocluster using the unique combination of three matched narrow-band filters, corresponding to Lyα, Hα, and [O iii] emission lines at z = 2.30. We find that Hα emitters are strongly clustered at the intersection of the filaments, suggesting a protocluster core. In contrast, Lyα emitters tend to avoid the dense region and the filaments, likely due to the resonant scattering of Lyα photons by H i gas and/or enhanced dust attenuation in galaxies associated with these structures. These findings support a scenario in which cold gas flows via filaments and to the core, fed by the cold-stream mode accretion in the early phase of protocluster assembly, and promoting active star formation there. Further evidence of the scenario comes from the alignment of massive, evolved galaxies in those filaments traced by distant red galaxies, suggesting accelerated galaxy growth in the filaments in the early Universe. This study clearly shows observationally that accelerated galaxy formation takes place not only in the protocluster core but also in the associated surrounding filamentary structure. This underscores the critical role of large-scale filaments in efficiently accumulating the cold gas and channeling it to galaxies therein and to the protocluster core. Such vigorous gas assembly facilitates star formation activity and drives galaxy growth in the early stage of cluster formation.
",
"doi": "10.1093/mnras/staf1772",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2025-12",
"series_number": "2",
"volume": "544",
"issue": "2",
"pages": "2365-2386"
},
{
"id": "authors:21tkj-yq961",
"collection": "authors",
"collection_id": "21tkj-yq961",
"cite_using_url": "https://authors.library.caltech.edu/records/21tkj-yq961",
"type": "article",
"title": "The AURORA Survey: The Nebular Attenuation Curve of a Galaxy at z = 4.41 from Ultraviolet to Near-infrared Wavelengths",
"author": [
{
"family_name": "Sanders",
"given_name": "Ryan L.",
"orcid": "0000-0003-4792-9119"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855"
},
{
"family_name": "Topping",
"given_name": "Michael W.",
"orcid": "0000-0001-8426-1141"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973"
},
{
"family_name": "Berg",
"given_name": "Danielle A.",
"orcid": "0000-0002-4153-053X"
},
{
"family_name": "Bouwens",
"given_name": "Rychard J.",
"orcid": "0000-0002-4989-2471"
},
{
"family_name": "Brammer",
"given_name": "Gabriel",
"orcid": "0000-0003-2680-005X"
},
{
"family_name": "Carnall",
"given_name": "Adam C.",
"orcid": "0000-0002-1482-5818"
},
{
"family_name": "Cullen",
"given_name": "Fergus",
"orcid": "0000-0002-3736-476X"
},
{
"family_name": "Dav\u00e9",
"given_name": "Romeel",
"orcid": "0000-0003-2842-9434"
},
{
"family_name": "Dunlop",
"given_name": "James S."
},
{
"family_name": "Ellis",
"given_name": "Richard S.",
"orcid": "0000-0001-7782-7071",
"clpid": "Ellis-R-S"
},
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"orcid": "0000-0003-4264-3381"
},
{
"family_name": "Furlanetto",
"given_name": "Steven R.",
"orcid": "0000-0002-0658-1243"
},
{
"family_name": "Glazebrook",
"given_name": "Karl",
"orcid": "0000-0002-3254-9044"
},
{
"family_name": "Illingworth",
"given_name": "Garth D.",
"orcid": "0000-0002-8096-2837"
},
{
"family_name": "Jones",
"given_name": "Tucker",
"orcid": "0000-0001-5860-3419"
},
{
"family_name": "Kriek",
"given_name": "Mariska",
"orcid": "0000-0002-7613-9872"
},
{
"family_name": "McLeod",
"given_name": "Derek J.",
"orcid": "0000-0003-4368-3326"
},
{
"family_name": "McLure",
"given_name": "Ross J."
},
{
"family_name": "Narayanan",
"given_name": "Desika",
"orcid": "0000-0002-7064-4309"
},
{
"family_name": "Oesch",
"given_name": "Pascal A.",
"orcid": "0000-0001-5851-6649"
},
{
"family_name": "Pahl",
"given_name": "Anthony J.",
"orcid": "0000-0003-4464-4505"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359"
},
{
"family_name": "Schaerer",
"given_name": "Daniel",
"orcid": "0000-0001-7144-7182"
},
{
"family_name": "Stark",
"given_name": "Daniel P."
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Tang",
"given_name": "Mengtao",
"orcid": "0000-0001-5940-338X"
},
{
"family_name": "Clarke",
"given_name": "Leonardo",
"orcid": "0000-0003-1249-6392"
},
{
"family_name": "Donnan",
"given_name": "Callum T.",
"orcid": "0000-0002-7622-0208"
},
{
"family_name": "Kehoe",
"given_name": "Emily"
}
],
"abstract": "\n
We use JWST/NIRSpec observations from the Assembly of Ultradeep Rest-optical Observations Revealing Astrophysics survey to constrain the shape of the nebular attenuation curve of a star-forming galaxy at z = 4.41, GOODSN-17940. We utilize 12 H i recombination lines to derive the attenuation curve spanning optical to near-infrared wavelengths (3751–9550 Å). We then leverage a high signal-to-noise ratio spectroscopic detection of the rest-frame ultraviolet continuum in combination with rest-UV photometric measurements to constrain the shape of the curve at ultraviolet wavelengths. While this UV constraint is predominantly based on stellar emission, the large measured equivalent widths of Hα and Hβ indicate that GOODSN-17940 is dominated by an extremely young stellar population <10 Myr in age such that the UV stellar continuum experiences similar attenuation to that of the nebular emission. The resulting combined nebular attenuation curve spans 1400–9550 Å and has a shape that deviates significantly from commonly assumed dust curves in high-redshift studies. Relative to the Milky Way, SMC, and Calzetti curves, the new curve has a steeper slope at long wavelengths (λ > 5000 Å) while displaying a similar slope across blue-optical wavelengths (λ = 3750–5000 Å). In the ultraviolet, the new curve is shallower than the SMC and Calzetti curves and displays no significant 2175 Å bump. This work demonstrates that the most commonly assumed dust curves are not appropriate for all high-redshift galaxies. These results highlight the ability to derive nebular attenuation curves for individual high-redshift sources with deep JWST/NIRSpec spectroscopy, thereby improving the accuracy of physical properties inferred from nebular emission lines.
\n
The metal enrichment of a galaxy is determined by the cycle of baryons in outflows, inflows, and star formation. The relative contribution and timescale of each process sets the relationship between stellar mass, metallicity, and the star formation rate (SFR). In the local Universe, galaxies evolve in an equilibrium state where the timescales on which SFR and metallicity vary are comparable, and they define a surface in mass–metallicity–SFR space known as the fundamental metallicity relation (FMR). However, high-redshift observations suggest that this state of equilibrium may not persist throughout cosmic time. Using galaxies from the Keck Baryonic Structure Survey (KBSS) observed with MOSFIRE, we explore the relationship between stellar mass, gas-phase oxygen abundance, and SFR at z ∼ 2.3. Across multiple strong-line calibrations and SFR calculation methods, KBSS galaxies are inconsistent with the locally defined FMR. We use both parametric and nonparametric methods of exploring a mass–metallicity–SFR relation. When using a parametric approach, we find no significant reduction mass–metallicity relation scatter when folding in SFR as a third parameter, although a nonparametric approach reveals that there could be a weak, redshift-dependent anticorrelation between residual gas-phase oxygen abundance and SFR. Injection-recovery tests show that a significant reduction in scatter requires a stronger anticorrelation between SFR and residual metallicity. Our results suggest that the local FMR may not persist to z ∼ 2.3, implying that z ∼ 2.3 galaxies at this redshift may not be in the equilibrium state described by the FMR and are more similar to higher-redshift galaxies.
",
"doi": "10.3847/1538-4357/adc5f7",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2025-05-10",
"series_number": "2",
"volume": "984",
"issue": "2",
"pages": "188"
},
{
"id": "authors:8xj12-4hy72",
"collection": "authors",
"collection_id": "8xj12-4hy72",
"cite_using_url": "https://authors.library.caltech.edu/records/8xj12-4hy72",
"type": "article",
"title": "A 100 Mpc\u00b2 Structure Traced by Hyperluminous Galaxies around a Massive z = 2.85 Protocluster",
"author": [
{
"family_name": "Wang",
"given_name": "George C. P.",
"orcid": "0009-0003-4626-9777"
},
{
"family_name": "Chapman",
"given_name": "Scott C.",
"orcid": "0000-0002-8487-3153"
},
{
"family_name": "Sulzenauer",
"given_name": "Nikolaus",
"orcid": "0000-0002-3187-1648"
},
{
"family_name": "Bertoldi",
"given_name": "Frank",
"orcid": "0000-0002-1707-1775"
},
{
"family_name": "Hayward",
"given_name": "Christopher C.",
"orcid": "0000-0003-4073-3236"
},
{
"family_name": "Hill",
"given_name": "Ryley",
"orcid": "0009-0008-8718-0644"
},
{
"family_name": "Kikuta",
"given_name": "Satoshi",
"orcid": "0000-0003-3214-9128"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"orcid": "0000-0003-1747-2891"
},
{
"family_name": "Rennehan",
"given_name": "Douglas",
"orcid": "0000-0002-1619-8555"
},
{
"family_name": "Scott",
"given_name": "Douglas",
"orcid": "0000-0002-6878-9840"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "\n
We present wide-field mapping at 850 μm and 450 μm of the z = 2.85 protocluster in the HS 1549+19 field using the Submillimetre Common-User Bolometer Array 2. Spectroscopic follow-up of 18 bright sources selected at 850 μm, using the Northern Extended Millimeter Array and Atacama Large Millimeter/submillimeter Array, confirms that the majority lie near z \u2243 2.85 and are likely members of the structure. Interpreting the spectroscopic redshifts as distance measurements, we find that the submillimeter galaxies (SMGs) span 123 pMpc2 in the plane of the sky and demarcate a 3600 pMpc3 \"pancake\"-shaped structure in three dimensions. We find that the high star formation rates of these SMGs result in a total star formation rate of 20,000 M\u2299 yr−1 from just the brightest galaxies in the protocluster. These rapidly star-forming SMGs can be interpreted as massive galaxies growing rapidly at large clustercentric distances before collapsing into a virialized structure. We find that the SMGs trace the Lyα surface density profile. Comparison with simulations suggests that HS 1549+19 could be building a structure comparable to the most massive clusters in the present-day Universe.
\n
In the present-day universe, the most massive galaxies are ellipticals located in the cores of galaxy clusters, harboring the heaviest super-massive black holes (SMBHs). However, the mechanisms that drive the early growth phase and subsequent transformation of the morphology and kinematics of galaxies remain elusive. Here we report (sub)kiloparsec-scale observations of stars, gas, and dust in ADF22.A1, a bright dusty starburst galaxy at $z=3.1$, hosting a heavily obscured active galactic nucleus and residing in a proto-cluster core. ADF22.A1 is a giant spiral galaxy with the kinematics of a rotating disk with rotation velocity $V_{\\rm rot}=530\\pm 10$ km s$^{-1}$ and diameter >30 kpc. The high specific stellar angular momentum of this system, $j_*=3400\\pm 600$ kpc km s$^{-1}$, requires a mechanism to effectively spin-up ADF22.A1, indicating the importance of accretion from the cosmic web to supply both gas and angular momentum to galaxies in their early gas-rich starburst phase. In its inner region, gas flows along dust lanes in a bar connected with the bright dusty core and the estimated mass ratio of the bulge to the SMBH matches the local relation, suggesting that bars are a key mechanism to shape the early co-evolution of these components. Comparison with cosmological simulations shows that ADF22.A1 will likely evolve into a massive elliptical, experiencing a significant reduction in angular momentum associated with subsequent galaxy mergers.
",
"doi": "10.1093/pasj/psaf010",
"issn": "0004-6264",
"publisher": "Oxford University Press (OUP)",
"publication": "Publications of the Astronomical Society of Japan",
"publication_date": "2025-04",
"series_number": "2",
"volume": "77",
"issue": "2",
"pages": "432-445"
},
{
"id": "authors:m84et-zd304",
"collection": "authors",
"collection_id": "m84et-zd304",
"cite_using_url": "https://authors.library.caltech.edu/records/m84et-zd304",
"type": "article",
"title": "Connecting the growth of galaxies to the large-scale environment in a massive node of the Cosmic Web at z \u223c\u20043",
"author": [
{
"family_name": "Galbiati",
"given_name": "M.",
"orcid": "0000-0002-1843-1699"
},
{
"family_name": "Cantalupo",
"given_name": "S.",
"orcid": "0000-0001-5804-1428"
},
{
"family_name": "Steidel",
"given_name": "C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pensabene",
"given_name": "A.",
"orcid": "0000-0001-9815-4953"
},
{
"family_name": "Travascio",
"given_name": "A.",
"orcid": "0000-0002-8863-888X"
},
{
"family_name": "Wang",
"given_name": "W.",
"orcid": "0000-0002-9593-8274"
},
{
"family_name": "Fossati",
"given_name": "M.",
"orcid": "0000-0002-9043-8764"
},
{
"family_name": "Fumagalli",
"given_name": "M.",
"orcid": "0000-0001-6676-3842"
},
{
"family_name": "Rudie",
"given_name": "G.",
"orcid": "0000-0002-8459-5413"
},
{
"family_name": "Fresco",
"given_name": "A.",
"orcid": "0000-0002-0535-1411"
},
{
"family_name": "Lazeyras",
"given_name": "T.",
"orcid": "0000-0002-7080-9839"
},
{
"family_name": "Ledos",
"given_name": "N.",
"orcid": "0000-0001-9699-8941"
},
{
"family_name": "Quadri",
"given_name": "G.",
"orcid": "0009-0005-9819-5620"
}
],
"abstract": "A direct link between the large-scale environment and galaxy properties is very well established in the local Universe. However, very little is known about the role of the environment for galaxy growth before the peak of the cosmic star formation history at z\u2004>\u20043 due to the rarity of high-redshift, overdense structures. Using a combination of deep, multiwavelength observations, including MUSE, JWST, Chandra, HST, and ground-based imaging, we detected and studied the properties of a population of star-forming galaxies in the field of a hyperluminous quasar at z\u2004≈\u20043.25 associated with the giant Lyα nebula MQN01. We find that this region hosts one of the largest overdensities of galaxies discovered so far at z\u2004>\u20043, with ρ/ρ\u0304\u2005=\u200553\u2005±\u200517 within 4\u2005×\u20054\u2006cMpc2 and |Δv|≤1000\u2006km\u2006s−1 from the quasar, providing a unique laboratory for studying the link between overdense regions and galaxy properties at high redshift. Even in these rare overdense regions, galaxies form stars at a rate consistent with the main sequence at z\u2004≈\u20043, demonstrating that their star formation rate (SFR) is regulated by local properties correlated with their stellar mass rather than by their environment. However, the high-mass end of the stellar mass function is significantly elevated with respect to that of galaxies in the field at log(M\u22c6/M\u2299)\u227310.5, suggesting that massive galaxies in overdense regions build up their stellar mass earlier or more efficiently than in average regions of the Universe. Finally, the overdensity of color-selected Lyman break galaxies observed on larger scales, across ≈24\u2005×\u200524\u2006cMpc2, is found to be aligned toward the structure traced by the spectroscopically confirmed galaxies identified with MUSE in the inner 4\u2005×\u20054\u2006cMpc2, suggesting that this highly overdense region could extend further, up to a few tens of comoving megaparsecs.
",
"doi": "10.1051/0004-6361/202452493",
"issn": "0004-6361",
"publisher": "EDP Sciences",
"publication": "Astronomy and Astrophysics",
"publication_date": "2025-04",
"volume": "696",
"pages": "A95"
},
{
"id": "authors:4jp2n-g0s18",
"collection": "authors",
"collection_id": "4jp2n-g0s18",
"cite_using_url": "https://authors.library.caltech.edu/records/4jp2n-g0s18",
"type": "article",
"title": "Gas Accretion Traced by Blue-dominated Ly\u03b1 Emission and Redshifted UV Absorption Lines in Protocluster Galaxies at z = 2.3 from the KBSS-KCWI Survey",
"author": [
{
"family_name": "Bolda",
"given_name": "Claire",
"orcid": "0000-0002-6913-8580"
},
{
"family_name": "Li \u674e",
"given_name": "Zhihui \u667a\u6167",
"orcid": "0000-0001-5113-7558",
"clpid": "Li-Zhihui"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chen \u9648",
"given_name": "Yuguang \u6631\u5149",
"orcid": "0000-0003-4520-5395"
}
],
"abstract": "Lyα emission with a dominant blueshifted peak can probe gas flowing through the circumgalactic medium as it accretes onto galaxies and fuels new star formation, although it has seldom actually been observed. Here we present new Keck Cosmic Web Imager observations of the extended Lyα halos surrounding Q1700-BX710 and Q1700-BX711, a pair of UV continuum-selected Keck Baryonic Structure Survey galaxies at z = 2.3 in the HS1700+643 protocluster. We find that BX710's and BX711's Lyα halos are aligned with a large-scale galaxy filament consisting of 13 spectroscopically identified protocluster galaxies. By measuring the peak separation and blue-to-red peak flux ratio of the Lyα emission profiles throughout these galaxies' Lyα halos, we have obtained measurements of their spatially varying velocity structure. The prevalence of blue-dominated Lyα emission profiles throughout BX711's Lyα halo suggests actively accreting gas. We fit a clumpy, multiphase Monte Carlo Radiative Transfer model, which assumes a radially varying clump velocity to the spatially resolved Lyα emission throughout BX710's and BX711's Lyα halos and simultaneously fit these galaxies' average down-the-barrel UV absorption profile with a radially varying velocity model. The results of these models are consistent with a combination of H i and higher-metallicity gas accretion for both galaxies, especially BX711, which exhibits inflow-driven kinematics throughout most of its Lyα halo. We consider various accretion scenarios to explain these findings, including accretion of metal-enriched gas from the cosmic web, galaxy interactions, and recycled gas from the circumgalactic medium, all of which are compatible with our current observations.
",
"doi": "10.3847/1538-4357/adb586",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2025-03-20",
"series_number": "1",
"volume": "982",
"issue": "1",
"pages": "54"
},
{
"id": "authors:gghnf-a4q25",
"collection": "authors",
"collection_id": "gghnf-a4q25",
"cite_using_url": "https://authors.library.caltech.edu/records/gghnf-a4q25",
"type": "article",
"title": "The AURORA Survey: An Extraordinarily Mature, Star-forming Galaxy at z\u00a0\u223c\u00a07",
"author": [
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855"
},
{
"family_name": "Sanders",
"given_name": "Ryan L.",
"orcid": "0000-0003-4792-9119"
},
{
"family_name": "Topping",
"given_name": "Michael W.",
"orcid": "0000-0001-8426-1141"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973"
},
{
"family_name": "Pahl",
"given_name": "Anthony J.",
"orcid": "0000-0003-4464-4505"
},
{
"family_name": "Oesch",
"given_name": "Pascal A.",
"orcid": "0000-0001-5851-6649"
},
{
"family_name": "Berg",
"given_name": "Danielle A.",
"orcid": "0000-0002-4153-053X"
},
{
"family_name": "Bouwens",
"given_name": "Rychard J.",
"orcid": "0000-0002-4989-2471"
},
{
"family_name": "Brammer",
"given_name": "Gabriel",
"orcid": "0000-0003-2680-005X"
},
{
"family_name": "Carnall",
"given_name": "Adam C.",
"orcid": "0000-0002-1482-5818"
},
{
"family_name": "Cullen",
"given_name": "Fergus",
"orcid": "0000-0002-3736-476X"
},
{
"family_name": "Dav\u00e9",
"given_name": "Romeel",
"orcid": "0000-0003-2842-9434"
},
{
"family_name": "Dunlop",
"given_name": "James S."
},
{
"family_name": "Ellis",
"given_name": "Richard S.",
"orcid": "0000-0001-7782-7071"
},
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"orcid": "0000-0003-4264-3381"
},
{
"family_name": "Furlanetto",
"given_name": "Steven R.",
"orcid": "0000-0002-0658-1243"
},
{
"family_name": "Glazebrook",
"given_name": "Karl",
"orcid": "0000-0002-3254-9044"
},
{
"family_name": "Illingworth",
"given_name": "Garth D.",
"orcid": "0000-0002-8096-2837"
},
{
"family_name": "Jones",
"given_name": "Tucker",
"orcid": "0000-0001-5860-3419"
},
{
"family_name": "Kriek",
"given_name": "Mariska",
"orcid": "0000-0002-7613-9872"
},
{
"family_name": "McLeod",
"given_name": "Derek J.",
"orcid": "0000-0003-4368-3326"
},
{
"family_name": "McLure",
"given_name": "Ross J."
},
{
"family_name": "Narayanan",
"given_name": "Desika",
"orcid": "0000-0002-7064-4309"
},
{
"family_name": "Pettini",
"given_name": "Max"
},
{
"family_name": "Schaerer",
"given_name": "Daniel",
"orcid": "0000-0001-7144-7182"
},
{
"family_name": "Stark",
"given_name": "Daniel P."
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Tang",
"given_name": "Mengtao",
"orcid": "0000-0001-5940-338X"
},
{
"family_name": "Clarke",
"given_name": "Leonardo",
"orcid": "0000-0003-1249-6392"
},
{
"family_name": "Donnan",
"given_name": "Callum T.",
"orcid": "0000-0002-7622-0208"
},
{
"family_name": "Kehoe",
"given_name": "Emily"
}
],
"abstract": "We present the properties of a massive, large, dusty, metal-rich, star-forming galaxy at zspec = 6.73. GOODSN-100182 was observed with JWST/NIRSpec as part of the Assembly of Ultradeep Rest-optical Observations Revealing Astrophysics (AURORA) survey, and is also covered by public multiwavelength Hubble Space Telescope and JWST imaging. While the large stellar mass of GOODSN-100182 (∼1010 M\u2299) was indicated prior to JWST, NIRCam rest-frame optical imaging now reveals the presence of an extended disk (reff ∼ 1.5 kpc). In addition, the NIRSpec R ∼ 1000 spectrum of GOODSN-100182 includes the detection of a large suite of rest-frame optical nebular emission lines ranging in wavelength from [O ii] λ3727 up to [N ii] λ6583. The ratios of Balmer lines suggest significant dust attenuation (E(B−V)gas=0.40−0.09+0.10), consistent with the red rest-frame UV slope inferred for GOODSN-100182 (β = −0.50 ± 0.09). The star formation rate based on dust-corrected Hα emission is log(SFR(Hα)/M\u2299yr−1)=2.02−0.14+0.13, well above the z ∼ 7 star-forming main sequence in terms of specific star formation rate. Strikingly, the ratio of [N ii] λ6583/Hα emission suggests almost solar metallicity, as does the ratio ([O iii] λ5007/Hβ)/([N ii] λ6583/Hα) and the detection of the faint [Fe ii] λ4360 emission feature. Overall, the excitation and ionization properties of GOODSN-100182 more closely resemble those of typical star-forming galaxies at z ∼ 2–3 rather than z ∼ 7. Based on public spectroscopy of the GOODS-N field, we find that GOODSN-100182 resides within a significant galaxy overdensity, and is accompanied by a spectroscopically confirmed neighbor galaxy. GOODSN-100182 demonstrates the existence of mature, chemically enriched galaxies within the first billion years of cosmic time, whose properties must be explained by galaxy formation models.
",
"doi": "10.3847/1538-4357/adaf98",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2025-03-10",
"series_number": "2",
"volume": "981",
"issue": "2",
"pages": "167"
},
{
"id": "authors:ang0z-hgx10",
"collection": "authors",
"collection_id": "ang0z-hgx10",
"cite_using_url": "https://authors.library.caltech.edu/records/ang0z-hgx10",
"type": "article",
"title": "The AURORA Survey: A New Era of Emission-line Diagrams with JWST/NIRSpec",
"author": [
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855"
},
{
"family_name": "Sanders",
"given_name": "Ryan L.",
"orcid": "0000-0003-4792-9119"
},
{
"family_name": "Topping",
"given_name": "Michael W.",
"orcid": "0000-0001-8426-1141"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973"
},
{
"family_name": "Berg",
"given_name": "Danielle A.",
"orcid": "0000-0002-4153-053X"
},
{
"family_name": "Bouwens",
"given_name": "Rychard J.",
"orcid": "0000-0002-4989-2471"
},
{
"family_name": "Brammer",
"given_name": "Gabriel",
"orcid": "0000-0003-2680-005X"
},
{
"family_name": "Carnall",
"given_name": "Adam C.",
"orcid": "0000-0002-1482-5818"
},
{
"family_name": "Cullen",
"given_name": "Fergus",
"orcid": "0000-0002-3736-476X"
},
{
"family_name": "Dav\u00e9",
"given_name": "Romeel",
"orcid": "0000-0003-2842-9434"
},
{
"family_name": "Dunlop",
"given_name": "James S."
},
{
"family_name": "Ellis",
"given_name": "Richard S.",
"orcid": "0000-0001-7782-7071",
"clpid": "Ellis-R-S"
},
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"orcid": "0000-0003-4264-3381"
},
{
"family_name": "Furlanetto",
"given_name": "Steven R.",
"orcid": "0000-0002-0658-1243"
},
{
"family_name": "Glazebrook",
"given_name": "Karl",
"orcid": "0000-0002-3254-9044"
},
{
"family_name": "Illingworth",
"given_name": "Garth D.",
"orcid": "0000-0002-8096-2837"
},
{
"family_name": "Jones",
"given_name": "Tucker",
"orcid": "0000-0001-5860-3419"
},
{
"family_name": "Kriek",
"given_name": "Mariska",
"orcid": "0000-0002-7613-9872"
},
{
"family_name": "McLeod",
"given_name": "Derek J.",
"orcid": "0000-0003-4368-3326"
},
{
"family_name": "McLure",
"given_name": "Ross J."
},
{
"family_name": "Narayanan",
"given_name": "Desika",
"orcid": "0000-0002-7064-4309"
},
{
"family_name": "Oesch",
"given_name": "Pascal",
"orcid": "0000-0001-5851-6649"
},
{
"family_name": "Pahl",
"given_name": "Anthony J.",
"orcid": "0000-0003-4464-4505"
},
{
"family_name": "Pettini",
"given_name": "Max"
},
{
"family_name": "Schaerer",
"given_name": "Daniel",
"orcid": "0000-0001-7144-7182"
},
{
"family_name": "Stark",
"given_name": "Daniel P.",
"orcid": "0000-0001-6106-5172"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Tang",
"given_name": "Mengtao",
"orcid": "0000-0001-5940-338X"
},
{
"family_name": "Clarke",
"given_name": "Leonardo",
"orcid": "0000-0003-1249-6392"
},
{
"family_name": "Donnan",
"given_name": "Callum T.",
"orcid": "0000-0002-7622-0208"
},
{
"family_name": "Kehoe",
"given_name": "Emily"
}
],
"abstract": "\n
We present results on the emission-line properties of z = 1.4–7.5 star-forming galaxies in the Assembly of Ultradeep Rest-optical Observations Revealing Astrophysics (AURORA) Cycle 1 JWST/NIRSpec program. Based on its depth, continuous wavelength coverage from 1 to 5 μm, and medium spectral resolution (R ∼ 1000), AURORA includes detections of a large suite of nebular emission lines spanning a broad range in rest-frame wavelength. We investigate the locations of AURORA galaxies in multiple different emission-line diagrams, including traditional BPT diagrams of [O iii]λ5007/Hβ versus [N ii]λ6583/Hα, [S ii]λλ6717, 6731/Hα, and [O i]λ6300/Hα, and the ionization–metallicity diagram of [O iii]λ5007/[O ii]λ3727 (O32) versus ([O iii]λ5007+[O ii]λ3727)/Hβ (R23). We also consider a bluer rest-frame ionization–metallicity diagram introduced recently to characterize z > 10 galaxies, [Ne iii]λ3869/[O ii]λ3727 versus ([Ne iii]λ3869+[O ii]λ3727)/Hδ, as well as longer-wavelength diagnostic diagrams extending into the rest-frame near-IR: [O iii]λ5007/Hβ versus [S iii]λλ9069, 9532/[S ii]λλ6717, 6731 (S32), and He iλ1.083 μm/Paγ and [S iii]λ9532/Paγ versus [Fe ii]λ1.257μm/Paβ. With a significant boost in signal-to-noise ratio and large, representative samples of individual galaxy detections, the AURORA emission-line diagrams presented here definitively confirm a physical picture in which chemically young, α-enhanced, massive stars photoionize the interstellar medium (ISM) in distant galaxies with a harder ionizing spectrum at fixed nebular metallicity than in their z ∼ 0 counterparts. We also uncover previously unseen evolution prior to z ∼ 2 in the [O iii]λ5007/Hβ versus [N ii]λ6583/Hα diagram, which motivates deep NIRSpec observations at even higher redshift. Finally, we present the first statistical sample of rest-frame near-IR emission-line diagnostics in star-forming galaxies at high redshift. In order to truly interpret rest-frame near-IR line ratios including [Fe ii]λ1.257 μm, we must obtain better constraints on dust depletion in the high-redshift ISM.
\n
\n
We present Keck Cosmic Web Imager integral-field unit observations around extended Lyα halos of 27 typical star-forming galaxies with redshifts 2.0 < z < 3.2 drawn from the MOSFIRE Deep Evolution Field survey. We examine the average Lyα surface brightness profiles in bins of star formation rate (SFR), stellar mass (M*), age, stellar continuum reddening, SFR surface density (ΣSFR), and ΣSFR normalized by stellar mass (ΣsSFR). The scale lengths of the halos correlate with stellar mass, age, and stellar continuum reddening and anticorrelate with SFR, ΣSFR, and ΣsSFR. These results are consistent with a scenario in which the down-the-barrel fraction of Lyα emission is modulated by the low-column-density channels in the interstellar medium, and in which the neutral gas covering fraction is related to the physical properties of the galaxies. Specifically, we find that this covering fraction increases with stellar mass, age, and E(B − V) and decreases with SFR, ΣSFR, and ΣsSFR. We also find that the resonantly scattered Lyα emission suffers greater attenuation than the (nonresonant) stellar continuum emission, and that the difference in attenuation increases with stellar mass, age, and stellar continuum reddening, and decreases with ΣsSFR. These results imply that more reddened galaxies have more dust in their circumgalactic medium.
\n
We report for the first time a relationship between galaxy kinematics and net Lyman-α equivalent width (net Lyα EW) in star-forming galaxies during the epoch of peak cosmic star formation. Building on the previously reported broadband imaging segregation of Lyα-emitting and Lyα-absorbing Lyman break galaxies (LBGs) at z ∼ 2 (Paper I in this series) and previously at z ∼ 3, we use the Lyα spectral type classification method to study the relationship between net Lyα EW and nebular emission-line kinematics in samples of z ∼ 2 and z ∼ 3 LBGs drawn from the literature for which matching rest-frame UV photometry, consistently measured net Lyα EWs, and kinematic classifications from integral field unit spectroscopy are available. We show that z ∼ 2 and z ∼ 3 LBGs segregate in colour-magnitude space according to their kinematic properties and Lyman-α spectral type and conclude that LBGs with Lyα dominant in absorption (aLBGs) are almost exclusively rotation-dominated (presumably disc-like) systems, and LBGs with Lyα dominant in emission (eLBGs) characteristically have dispersion-dominated kinematics. We quantify the relationship between the strength of rotational dynamic support (as measured using v_(obs)/2σ_(int) and vrot/σ0) and net Lyα EW for subsets of our kinematic sample where these data are available, and demonstrate the consistency of our result with other properties that scale with net Lyα EW and kinematics. Based on these findings, we suggest a method by which large samples of rotation- and dispersion-dominated galaxies might be selected using broadband imaging in as few as three filters and/or net Lyα EW alone. If confirmed with larger samples, application of this method will enable an understanding of galaxy kinematic behaviour over large scales in datasets from current and future large-area and all-sky photometric surveys that will select hundreds of millions of LBGs in redshift ranges from z ∼ 2−6 across many hundreds to thousands of Mpc. Finally, we speculate that the combination of our result linking net Lyα EW and nebular emission-line kinematics with the known large-scale clustering behaviour of Lyα-absorbing and Lyα-emitting LBGs is evocative of an emergent bimodality of early galaxies that is consistent with a nascent morphology-density relation at z ∼ 2−3.
",
"doi": "10.1017/pasa.2023.61",
"issn": "1323-3580",
"publisher": "Cambridge University Press (CUP)",
"publication": "Publications of the Astronomical Society of Australia",
"publication_date": "2023-11-30",
"volume": "41",
"pages": "e005"
},
{
"id": "authors:qyj02-2sf87",
"collection": "authors",
"collection_id": "qyj02-2sf87",
"cite_using_url": "https://authors.library.caltech.edu/records/qyj02-2sf87",
"type": "article",
"title": "CECILIA: The Faint Emission Line Spectrum of z \u223c 2\u20133 Star-forming Galaxies",
"author": [
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322"
},
{
"family_name": "Brammer",
"given_name": "Gabriel B.",
"orcid": "0000-0003-2680-005X"
},
{
"family_name": "Maseda",
"given_name": "Michael V.",
"orcid": "0000-0003-0695-4414"
},
{
"family_name": "Raptis",
"given_name": "Menelaos",
"orcid": "0009-0008-2226-5241"
},
{
"family_name": "Rogers",
"given_name": "Noah S. J.",
"orcid": "0000-0002-0361-8223"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chen \u9648",
"given_name": "Yuguang \u6631\u5149",
"orcid": "0000-0003-4520-5395"
},
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X"
}
],
"abstract": "e present the first results from Chemical Evolution Constrained Using Ionized Lines in Interstellar Aurorae (CECILIA), a Cycle 1 JWST NIRSpec/MSA program that uses ultra-deep ∼30 hr G235M/F170LP observations to target multiple electron temperature-sensitive auroral lines in the spectra of 33 galaxies at z ∼ 1–3. Using a subset of 23 galaxies, we construct two ∼600 object-hour composite spectra, both with and without the stellar continuum, and use these to investigate the characteristic rest-optical (λrest ≈ 5700–8500 Å) spectrum of star-forming galaxies at the peak epoch of cosmic star formation. Emission lines of eight different elements (H, He, N, O, Si, S, Ar, and Ni) are detected, with most of these features observed to be \u22723% the strength of Hα. We report the characteristic strength of three auroral features ([N ii]λ5756, [S iii]λ6313, and [O ii]λλ7322, 7332), as well as other semi-strong and faint emission lines, including forbidden [Ni ii]λλ7380, 7414 and permitted O iλ8449, some of which have never before been observed outside of the local Universe. Using these measurements, we find Te[N ii] = 13,630 ± 2540 K, representing the first measurement of electron temperature using [N ii] in the high-redshift Universe. We also see evidence for broad line emission with a FWHM of 536−167+45 km s−1; the broad component of Hα is 6.01%–28.31% the strength of the narrow component and likely arises from star-formation-driven outflows. Finally, we briefly comment on the feasibility of obtaining large samples of faint emission lines using JWST in the future.
",
"doi": "10.3847/2041-8213/ad07dc",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2023-11-01",
"series_number": "1",
"volume": "958",
"issue": "1",
"pages": "L11"
},
{
"id": "authors:45tb2-2he34",
"collection": "authors",
"collection_id": "45tb2-2he34",
"cite_using_url": "https://authors.library.caltech.edu/records/45tb2-2he34",
"type": "article",
"title": "Lyman-\u03b1 at cosmic noon I: Ly\u03b1 spectral type selection of z \u223c 2 \u2013 3 Lyman break galaxies with broadband imaging",
"author": [
{
"family_name": "Foran",
"given_name": "Garry",
"orcid": "0000-0002-1916-5425"
},
{
"family_name": "Cooke",
"given_name": "Jeff"
},
{
"family_name": "Reddy",
"given_name": "Naveen",
"orcid": "0000-0001-9687-4973"
},
{
"family_name": "Steidel",
"given_name": "Charles",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice",
"orcid": "0000-0003-3509-4855"
}
],
"abstract": "High-redshift Lyman break galaxies (LBGs) are efficiently selected in deep images using as few as three broadband filters, and have been shown to have multiple intrinsic and small- to large-scale environmental properties related to Lyman-α. In this paper we demonstrate a statistical relationship between net Lyman-α equivalent width (net Lyα EW) and the optical broadband photometric properties of LBGs at z ∼ 2. We show that LBGs with the strongest net Lyα EW in absorption (aLBGs) and strongest net Lyα EW in emission (eLBGs) separate into overlapping but discrete distributions in (U_n−R) colour and R-band magnitude space, and use this segregation behaviour to determine photometric selection criteria by which sub-samples with a desired Lyα spectral type can be selected using data from as few as three broadband optical filters. We propose application of our result to current and future large-area and all-sky photometric surveys that will select hundreds of millions of LBGs across many hundreds to thousands of Mpc, and for which spectroscopic follow-up to obtain Lyα spectral information is prohibitive. To this end, we use spectrophotometry of composite spectra derived from a sample of 798 LBGs divided into quartiles on the basis of net Lyα EW to calculate selection criteria for the isolation of Lyα-absorbing and Lyα-emitting populations of z ∼ 3 LBGs using ugri broadband photometric data from the Vera Rubin Observatory Legacy Survey of Space and Time (LSST).
",
"doi": "10.1017/pasa.2023.48",
"issn": "1323-3580",
"publisher": "Cambridge University Press (CUP)",
"publication": "Publications of the Astronomical Society of Australia",
"publication_date": "2023-09-28",
"volume": "40",
"pages": "e052"
},
{
"id": "authors:37san-rnc03",
"collection": "authors",
"collection_id": "37san-rnc03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230531-151922700.2",
"type": "article",
"title": "A Glimpse of the Stellar Populations and Elemental Abundances of Gravitationally Lensed, Quiescent Galaxies at z \u2273 1 with Keck Deep Spectroscopy",
"author": [
{
"family_name": "Zhuang",
"given_name": "Zhuyun",
"orcid": "0000-0002-1945-2299",
"clpid": "Zhuang-Zhuyun"
},
{
"family_name": "Leethochawalit",
"given_name": "Nicha",
"orcid": "0000-0003-4570-3159",
"clpid": "Leethochawalit-Nicha"
},
{
"family_name": "Kirby",
"given_name": "Evan N.",
"orcid": "0000-0001-6196-5162",
"clpid": "Kirby-E-N"
},
{
"family_name": "Nightingale",
"given_name": "J. W.",
"orcid": "0000-0002-8987-7401",
"clpid": "Nightingale-James-W"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Glazebrook",
"given_name": "Karl",
"orcid": "0000-0002-3254-9044",
"clpid": "Glazebrook-Karl"
},
{
"family_name": "Barone",
"given_name": "Tania M.",
"orcid": "0000-0002-2784-564X",
"clpid": "Barone-Tania-M"
},
{
"family_name": "Skobe",
"given_name": "Hannah",
"orcid": "0000-0003-0516-3485",
"clpid": "Skobe-Hannah"
},
{
"family_name": "Sweet",
"given_name": "Sarah M.",
"orcid": "0000-0002-1576-2505",
"clpid": "Sweet-Sarah-M"
},
{
"family_name": "Nanayakkara",
"given_name": "Themiya",
"orcid": "0000-0003-2804-0648",
"clpid": "Nanayakkara-Themiya"
},
{
"family_name": "Allen",
"given_name": "Rebecca J.",
"orcid": "0000-0002-7278-9528",
"clpid": "Allen-Rebecca-J"
},
{
"family_name": "G. C.",
"given_name": "Keerthi Vasan",
"orcid": "0000-0002-2645-679X",
"clpid": "G-C-Keerthi-Vasan"
},
{
"family_name": "Jones",
"given_name": "Tucker",
"orcid": "0000-0001-5860-3419",
"clpid": "Jones-Tucker-A"
},
{
"family_name": "Kacprzak",
"given_name": "Glenn G.",
"orcid": "0000-0003-1362-9302",
"clpid": "Kacprzak-Glenn-G"
},
{
"family_name": "Tran",
"given_name": "Kim-Vy H.",
"orcid": "0000-0001-9208-2143",
"clpid": "Tran-Kim-Vy-H"
},
{
"family_name": "Jacobs",
"given_name": "Colin",
"orcid": "0000-0003-4239-4055",
"clpid": "Jacobs-Colin"
}
],
"abstract": "Gravitational lenses can magnify distant galaxies, allowing us to discover and characterize the stellar populations of intrinsically faint, quiescent galaxies that are otherwise extremely difficult to directly observe at high redshift from ground-based telescopes. Here, we present the spectral analysis of two lensed, quiescent galaxies at z \u2273 1 discovered by the ASTRO 3D Galaxy Evolution with Lenses survey: AGEL1323 (M_* \u223c 10^(11.1)M_\u2299, z = 1.016, \u03bc \u223c 14.6) and AGEL0014 (M_* \u223c 10^(11.5)M_\u2299, z = 1.374, \u03bc \u223c 4.3). We measured the age, [Fe/H], and [Mg/Fe] of the two lensed galaxies using deep, rest-frame-optical spectra (S/N \u2273 40 \u00c5\u207b\u00b9) obtained on the Keck I telescope. The ages of AGEL1323 and AGEL0014 are 5.6^(+0.8)_(\u22120.8) Gyr and 3.1^(+0.8)_(\u22120.3) Gyr, respectively, indicating that most of the stars in the galaxies were formed less than 2 Gyr after the Big Bang. Compared to nearby quiescent galaxies of similar masses, the lensed galaxies have lower [Fe/H] and [Mg/H]. Surprisingly, the two galaxies have comparable [Mg/Fe] to similar-mass galaxies at lower redshifts, despite their old ages. Using a simple analytic chemical evolution model connecting the instantaneously recycled element Mg with the mass-loading factors of outflows averaged over the entire star formation history, we found that the lensed galaxies may have experienced enhanced outflows during their star formation compared to lower-redshift galaxies, which may explain why they quenched early.",
"doi": "10.3847/1538-4357/acc79b",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2023-05-10",
"series_number": "2",
"volume": "948",
"issue": "2",
"pages": "Art. No. 132"
},
{
"id": "authors:j0qjc-8wf35",
"collection": "authors",
"collection_id": "j0qjc-8wf35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230420-956212500.3",
"type": "article",
"title": "The connection between the escape of ionizing radiation and galaxy properties at z \u223c 3 in the Keck Lyman continuum spectroscopic survey",
"author": [
{
"family_name": "Pahl",
"given_name": "Anthony J.",
"orcid": "0000-0003-4464-4505",
"clpid": "Pahl-Anthony-J"
},
{
"family_name": "Shapley",
"given_name": "Alice",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-Alice-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-Naveen-A"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-Gwen-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-Allison-L"
}
],
"abstract": "The connection between the escape fraction of ionizing radiation (f_(esc)) and the properties of galaxies, such as stellar mass (\u2060M_\u2217\u2060), age, star-formation rate (SFR), and dust content, are key inputs for reionization models, but many of these relationships remain untested at high redshift. We present an analysis of a sample of 96 z \u223c 3 galaxies from the Keck Lyman Continuum Spectroscopic Survey (KLCS). These galaxies have both sensitive Keck/LRIS spectroscopic measurements of the Lyman continuum (LyC) region, and multiband photometry that places constraints on stellar population parameters. We construct composite spectra from subsamples binned as a function of galaxy property and quantify the ionizing-photon escape for each composite. We find a significant anti-correlation between f_(esc) and M_\u2217\u2060, consistent with predictions from cosmological zoom-in simulations. We also find significant anti-correlation between f_(esc) and E(B\u2212V), encoding the underlying physics of LyC escape in our sample. We also find no significant correlation between fesc and either stellar age or specific SFR (= SFR/M_\u2217\u2060), challenging interpretations that synchronize recent star formation and favorable conditions for ionizing escape. The galaxy properties now shown to correlate with fesc in the KLCS are Ly\u03b1 equivalent width, UV Luminosity, M_\u2217\u2060, SFR, and E(B\u2212V), but not age or sSFR. This comprehensive analysis of galaxy properties and LyC escape at high redshift will be used to guide future models and observations of the reionization epoch.",
"doi": "10.1093/mnras/stad774",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2023-05",
"series_number": "3",
"volume": "521",
"issue": "3",
"pages": "3247-3259"
},
{
"id": "authors:z784y-84t72",
"collection": "authors",
"collection_id": "z784y-84t72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230601-111032400.7",
"type": "article",
"title": "UV and Ly\u03b1 Halos of Ly\u03b1 Emitters across Environments at z = 2.84",
"author": [
{
"family_name": "Kikuta",
"given_name": "Satoshi",
"orcid": "0000-0003-3214-9128",
"clpid": "Kikuta-Satoshi"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"orcid": "0000-0003-1747-2891",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Inoue",
"given_name": "Shigeki",
"orcid": "0000-0001-8819-6877",
"clpid": "Inoue-Shigeki"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Cen",
"given_name": "Renyue",
"orcid": "0000-0001-8531-9536",
"clpid": "Cen-Renyue"
},
{
"family_name": "Zheng",
"given_name": "Zheng",
"orcid": "0000-0003-1887-6732",
"clpid": "Zheng-Zheng"
},
{
"family_name": "Yajima",
"given_name": "Hidenobu",
"orcid": "0000-0002-1319-3433",
"clpid": "Yajima-Hidenobu"
},
{
"family_name": "Momose",
"given_name": "Rieko",
"orcid": "0000-0002-8857-2905",
"clpid": "Momose-Rieko"
},
{
"family_name": "Imanishi",
"given_name": "Masatoshi",
"orcid": "0000-0001-6186-8792",
"clpid": "Imanishi-Masatoshi"
},
{
"family_name": "Komiyama",
"given_name": "Yutaka",
"orcid": "0000-0002-3852-6329",
"clpid": "Komiyama-Yutaka"
}
],
"abstract": "We present UV and Ly\u03b1 radial surface brightness (SB) profiles of Ly\u03b1 emitters (LAEs) at z = 2.84 detected with the Hyper Suprime-Cam on the Subaru Telescope. The depth of our data, together with the wide-field coverage including a protocluster, enable us to study the dependence of Ly\u03b1 halos (LAHs) on various galaxy properties, including Mpc scale environments. UV and Ly\u03b1 images of 3490 LAEs are extracted, and stacking the images yields SB sensitivity of ~ 1 x 10\u207b\u00b2\u2070 erg s\u207b\u00b9 cm\u207b\u00b2 arcsec\u207b\u00b2 in Ly\u03b1, reaching the expected level of optically thick gas illuminated by the UV background at z \u223c 3. Fitting of the two-component exponential function gives the scale-lengths of 1.56 \u00b1 0.01 and 10.4 \u00b1 0.3 pkpc. Dividing the sample according to their photometric properties, we find that, while the dependence of halo scale-length on environment outside of the protocluster core is not clear, LAEs in the central regions of protoclusters appear to have very large LAHs, which could be caused by combined effects of source overlapping and diffuse Ly\u03b1 emission from cool intergalactic gas permeating the forming protocluster core irradiated by active members. For the first time, we identify UV halos around bright LAEs that are probably due to a few lower-mass satellite galaxies. Through comparison with recent numerical simulations, we conclude that, while scattered Ly\u03b1 photons from the host galaxies are dominant, star formation in satellites evidently contributes to LAHs, and that fluorescent Ly\u03b1 emission may be boosted within protocluster cores at cosmic noon and/or near bright QSOs.",
"doi": "10.3847/1538-4357/acbf30",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2023-04-20",
"series_number": "2",
"volume": "947",
"issue": "2",
"pages": "Art. No. 75"
},
{
"id": "authors:ah8yb-53f32",
"collection": "authors",
"collection_id": "ah8yb-53f32",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230314-844891400.3",
"type": "article",
"title": "Characterizing the circumgalactic medium of quasars at z \u223c 2.2 through H\u2009\u03b1 and Ly\u2009\u03b1 emission",
"author": [
{
"family_name": "Langen",
"given_name": "Vivienne",
"orcid": "0000-0002-9523-3880",
"clpid": "Langen-Vivienne"
},
{
"family_name": "Cantalupo",
"given_name": "Sebastiano",
"orcid": "0000-0001-5804-1428",
"clpid": "Cantalupo-Sebastiano"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
},
{
"family_name": "Pezzulli",
"given_name": "Gabriele",
"orcid": "0000-0003-0736-7879",
"clpid": "Pezzulli-Gabriele"
},
{
"family_name": "Gallego",
"given_name": "Sofia G.",
"orcid": "0000-0002-8825-8107",
"clpid": "Gallego-Sofia-G"
}
],
"abstract": "The discovery of giant quasar Ly\u2009\u03b1 nebulae at z > 2 has opened up the possibility to directly study in emission the Circumgalactic and Intergalactic Medium (CGM/IGM). However, the resonant nature of the Ly\u2009\u03b1 line and its different emission mechanisms hamper the ability to constrain both the kinematics and physical properties of the CGM/IGM. Here, we present results of a pilot project aiming at the detection of CGM H\u2009\u03b1 emission, a line which does not suffer from these limitations. To this end, we first used KCWI to detect Ly\u2009\u03b1 emission around three bright quasars with 2.25 < z < 2.27, a range which is free from bright IR sky lines for H\u2009\u03b1, and then selected the most extended nebula for H\u2009\u03b1 follow-up with MOSFIRE. Within the MOSFIRE slit, we detected H\u2009\u03b1 emission extending up to 20 physical kpc with a total H\u2009\u03b1 flux of F_(H\u2009\u03b1) = (9.5\u00a0\u00b1\u00a00.9) \u00d7 10\u207b\u00b9\u2078 erg s\u207b\u00b9, cm\u207b\u00b2. Considering the Ly\u2009\u03b1 flux in the same region, we found F_(Ly\u2009\u03b1)/F_(H\u2009\u03b1) = 3.7\u00a0\u00b1\u00a00.3 consistent with that obtained for the Slug Nebula at z = 2.275 and with recombination radiation. This implies high densities or a very broad density distribution within the CGM of high-redshift quasars. Moreover, the H\u2009\u03b1 line profile suggests the presence of multiple emitting components overlapping along our line of\u00a0sight and relatively quiescent kinematics, which seems incompatible with either quasar outflows capable of escaping the potential well of the host halo or disc-like rotation in a massive halo (>10\u00b9\u00b2 M_\u2299).",
"doi": "10.1093/mnras/stac3205",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2023-03",
"series_number": "4",
"volume": "519",
"issue": "4",
"pages": "5099-5113"
},
{
"id": "authors:eht42-gm086",
"collection": "authors",
"collection_id": "eht42-gm086",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220928-285212100.17",
"type": "article",
"title": "CLASSY. II. A Technical Overview of the COS Legacy Archive Spectroscopic Survey",
"author": [
{
"family_name": "James",
"given_name": "Bethan L.",
"orcid": "0000-0003-4372-2006",
"clpid": "James-Bethan-L"
},
{
"family_name": "Berg",
"given_name": "Danielle A.",
"orcid": "0000-0002-4153-053X"
},
{
"family_name": "King",
"given_name": "Teagan",
"orcid": "0000-0003-0834-4150"
},
{
"family_name": "Sahnow",
"given_name": "David J.",
"orcid": "0000-0001-9594-161X"
},
{
"family_name": "Mingozzi",
"given_name": "Matilde",
"orcid": "0000-0003-2589-762X"
},
{
"family_name": "Chisholm",
"given_name": "John",
"orcid": "0000-0002-0302-2577"
},
{
"family_name": "Heckman",
"given_name": "Timothy",
"orcid": "0000-0003-1127-7497"
},
{
"family_name": "Martin",
"given_name": "Crystal L.",
"orcid": "0000-0001-9189-7818"
},
{
"family_name": "Stark",
"given_name": "Dan P."
},
{
"family_name": "Aloisi",
"given_name": "Alessandra",
"orcid": "0000-0003-4137-882X"
},
{
"family_name": "Amor\u00edn",
"given_name": "Ricardo O.",
"orcid": "0000-0001-5758-1000"
},
{
"family_name": "Arellano-C\u00f3rdova",
"given_name": "Karla Z.",
"orcid": "0000-0002-2644-3518"
},
{
"family_name": "Bayliss",
"given_name": "Matthew",
"orcid": "0000-0003-1074-4807"
},
{
"family_name": "Bordoloi",
"given_name": "Rongmon",
"orcid": "0000-0002-3120-7173"
},
{
"family_name": "Brinchmann",
"given_name": "Jarle",
"orcid": "0000-0003-4359-8797"
},
{
"family_name": "Charlot",
"given_name": "St\u00e9phane",
"orcid": "0000-0003-3458-2275"
},
{
"family_name": "Chen",
"given_name": "Zuyi",
"orcid": "0000-0002-2178-5471"
},
{
"family_name": "Chevallard",
"given_name": "Jacopo",
"orcid": "0000-0002-7636-0534"
},
{
"family_name": "Clark",
"given_name": "Ilyse",
"orcid": "0000-0003-3334-4267"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758"
},
{
"family_name": "Feltre",
"given_name": "Anna",
"orcid": "0000-0001-6865-2871"
},
{
"family_name": "Hayes",
"given_name": "Matthew",
"orcid": "0000-0001-8587-218X"
},
{
"family_name": "Henry",
"given_name": "Alaina",
"orcid": "0000-0002-6586-4446"
},
{
"family_name": "Hernandez",
"given_name": "Svea",
"orcid": "0000-0003-4857-8699"
},
{
"family_name": "Jaskot",
"given_name": "Anne",
"orcid": "0000-0002-6790-5125"
},
{
"family_name": "Kewley",
"given_name": "Lisa J.",
"orcid": "0000-0001-8152-3943"
},
{
"family_name": "Kumari",
"given_name": "Nimisha",
"orcid": "0000-0002-5320-2568"
},
{
"family_name": "Leitherer",
"given_name": "Claus",
"orcid": "0000-0003-2685-4488"
},
{
"family_name": "Llerena",
"given_name": "Mario",
"orcid": "0000-0003-1354-4296"
},
{
"family_name": "Maseda",
"given_name": "Michael",
"orcid": "0000-0003-0695-4414"
},
{
"family_name": "Nanayakkara",
"given_name": "Themiya",
"orcid": "0000-0003-2804-0648"
},
{
"family_name": "Ouchi",
"given_name": "Masami",
"orcid": "0000-0002-1049-6658"
},
{
"family_name": "Plat",
"given_name": "Adele",
"orcid": "0000-0003-0390-0656"
},
{
"family_name": "Pogge",
"given_name": "Richard W.",
"orcid": "0000-0003-1435-3053"
},
{
"family_name": "Ravindranath",
"given_name": "Swara",
"orcid": "0000-0002-5269-6527"
},
{
"family_name": "Rigby",
"given_name": "Jane R.",
"orcid": "0000-0002-7627-6551"
},
{
"family_name": "Scarlata",
"given_name": "Claudia",
"orcid": "0000-0002-9136-8876"
},
{
"family_name": "Senchyna",
"given_name": "Peter",
"orcid": "0000-0002-9132-6561"
},
{
"family_name": "Skillman",
"given_name": "Evan D.",
"orcid": "0000-0003-0605-8732"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Sugahara",
"given_name": "Yuma",
"orcid": "0000-0001-6958-7856"
},
{
"family_name": "Wilkins",
"given_name": "Stephen M.",
"orcid": "0000-0003-3903-6935"
},
{
"family_name": "Wofford",
"given_name": "Aida",
"orcid": "0000-0001-8289-3428"
},
{
"family_name": "Xu",
"given_name": "Xinfeng",
"orcid": "0000-0002-9217-7051"
},
{
"literal": "CLASSY Team"
}
],
"abstract": "The COS Legacy Archive Spectroscopic SurveY (CLASSY) is designed to provide the community with a spectral atlas of 45 nearby star-forming galaxies that were chosen to cover similar properties to those seen at high z (z > 6). The prime high-level science product of CLASSY is accurately coadded UV spectra, ranging from \u223c1000 to 2000 \u00c5, derived from a combination of archival and new data obtained with HST's Cosmic Origins Spectrograph (COS). This paper details the multistage technical processes of creating this prime data product and the methodologies involved in extracting, reducing, aligning, and coadding far-ultraviolet and near-ultraviolet (NUV) spectra. We provide guidelines on how to successfully utilize COS observations of extended sources, despite COS being optimized for point sources, and best-practice recommendations for the coaddition of UV spectra in general. Moreover, we discuss the effects of our reduction and coaddition techniques in the scientific application of the CLASSY data. In particular, we find that accurately accounting for flux calibration offsets can affect the derived properties of the stellar populations, while customized extractions of NUV spectra for extended sources are essential for correctly diagnosing the metallicity of galaxies via C iii] nebular emission. Despite changes in spectral resolution of up to \u223c25% between individual data sets (due to changes in the COS line-spread function), no adverse affects were observed on the difference in velocity width and outflow velocities of isolated absorption lines when measured in the final combined data products, owing in part to our signal-to-noise regime of S/N < 20.",
"doi": "10.3847/1538-4365/ac8008",
"issn": "0067-0049",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Supplement Series",
"publication_date": "2022-10",
"series_number": "2",
"volume": "262",
"issue": "2",
"pages": "Art. No. 37"
},
{
"id": "authors:kswgq-bxq72",
"collection": "authors",
"collection_id": "kswgq-bxq72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220926-576554400.10",
"type": "article",
"title": "Searching for the connection between ionizing-photon escape and the surface density of star formation at z \u223c 3",
"author": [
{
"family_name": "Pahl",
"given_name": "Anthony J.",
"orcid": "0000-0003-4464-4505",
"clpid": "Pahl-Anthony-J"
},
{
"family_name": "Shapley",
"given_name": "Alice",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-Naveen-A"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
}
],
"abstract": "The connection between the escape fraction of ionizing photons (f_(esc)) and star formation rate surface density (\u03a3_(SFR)) is a key input for reionization models, but remains untested at high redshift. We analyse 35 z \u223c 3 galaxies from the Keck Lyman Continuum Survey (KLCS) covered by deep, rest far-UV spectra of the Lyman continuum (LyC) and high-resolution HST V_(606) imaging, enabling estimates of both f_(esc) and rest-UV sizes. Using S\u00e9rsic profile fits to HST images and spectral-energy distribution fits to multiband photometry, we measure effective sizes and SFRs for the galaxies in our sample, and separate the sample into two bins of \u03a3_(SFR). Based on composite spectra, we estimate \u3008f_(esc)\u3009 for both \u03a3_(SFR) subsamples, finding no significant difference in \u3008f_(esc)\u3009 between the two. To test the representativeness of the KLCS HST sample and robustness of this result, we attempt to recover the well-established correlation between f_(esc) and Ly\u03b1 equivalent width. This correlation is not significant within the KLCS HST sample, indicating that the sample is insufficient for correlating f_(esc) and galaxy properties such as \u03a3_(SFR). We perform stacking simulations using the KLCS parent sample to determine the optimal sample size for robust probes of the f_(esc)-\u03a3_(SFR) connection to inform future observing programs. For a program with a selection independent of ionizing properties, \u226590 objects are required; for one preferentially observing strongly-leaking LyC sources, \u226558 objects are required. More generally, measuring the connection between f_(esc) and \u03a3_(SFR) requires a larger, representative sample spanning a wide dynamic range in galaxies properties such as \u03a3_(SFR).",
"doi": "10.1093/mnras/stac1767",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2022-10",
"series_number": "2",
"volume": "516",
"issue": "2",
"pages": "2062-2073"
},
{
"id": "authors:q6bbq-hda57",
"collection": "authors",
"collection_id": "q6bbq-hda57",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220908-183409314",
"type": "article",
"title": "An AGN with an Ionized Gas Outflow in a Massive Quiescent Galaxy in a Protocluster at z = 3.09",
"author": [
{
"family_name": "Kubo",
"given_name": "Mariko",
"orcid": "0000-0002-7598-5292",
"clpid": "Kubo-Mariko"
},
{
"family_name": "Umehata",
"given_name": "Hideki",
"orcid": "0000-0003-1937-0573",
"clpid": "Umehata-Hideki"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"orcid": "0000-0003-1747-2891",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Kajisawa",
"given_name": "Masaru",
"orcid": "0000-0002-1732-6387",
"clpid": "Kajisawa-Masaru"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Yamada",
"given_name": "Toru",
"clpid": "Yamada-Toru"
},
{
"family_name": "Tanaka",
"given_name": "Ichi",
"orcid": "0000-0002-4937-4738",
"clpid": "Tanaka-Ichi"
},
{
"family_name": "Hatsukade",
"given_name": "Bunyo",
"orcid": "0000-0001-6469-8725",
"clpid": "Hatsukade-Bunyo"
},
{
"family_name": "Tamura",
"given_name": "Yoichi",
"orcid": "0000-0003-4807-8117",
"clpid": "Tamura-Yoichi"
},
{
"family_name": "Nakanishi",
"given_name": "Kouichiro",
"orcid": "0000-0002-6939-0372",
"clpid": "Nakanishi-Kouichiro"
},
{
"family_name": "Kohno",
"given_name": "Kotaro",
"orcid": "0000-0002-4052-2394",
"clpid": "Kohno-Kotaro"
},
{
"family_name": "Lee",
"given_name": "Kianhong",
"orcid": "0000-0003-4814-0101",
"clpid": "Lee-Kianhong"
},
{
"family_name": "Matsuda",
"given_name": "Keiichi",
"clpid": "Matsuda-Keiichi"
},
{
"family_name": "Ao",
"given_name": "Yiping",
"orcid": "0000-0003-3139-2724",
"clpid": "Ao-Yiping"
},
{
"family_name": "Nagao",
"given_name": "Tohru",
"orcid": "0000-0002-7402-5441",
"clpid": "Nagao-Tohru"
},
{
"family_name": "Yun",
"given_name": "Min S.",
"orcid": "0000-0001-7095-7543",
"clpid": "Yun-Min-S"
}
],
"abstract": "We report the detection of an ionized gas outflow from an X-ray active galactic nucleus hosted in a massive quiescent galaxy in a protocluster at z = 3.09 (J221737.29+001823.4). It is a type-2 QSO with broad (W_80 > 1000 km s^(\u22121)) and strong (log(L[OIII]/erg s^(\u22121)) \u2248 43.4) [O III]\u03bb\u03bb 4959,5007 emission lines detected by slit spectroscopy in three-position angles using Multi-Object Infra-Red Camera and Spectrograph (MOIRCS) on the Subaru telescope and the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck-I telescope. In the all slit directions, [O III] emission is extended to \u223c15 physical kpc and indicates a powerful outflow spreading over the host galaxy. The inferred ionized gas mass outflow rate is 22 \u00b1 3 M_\u2299 yr^(\u22121). Although it is a radio source, according to the line diagnostics using H\u03b2, [O II], and [O III], photoionization by the central QSO is likely the dominant ionization mechanism rather than shocks caused by radio jets. On the other hand, the spectral energy distribution of the host galaxy is well characterized as a quiescent galaxy that has shut down star formation several hundred Myr ago. Our results suggest a scenario that QSOs are powered after the shutdown of the star formation and help complete the quenching of massive quiescent galaxies at high redshift.",
"doi": "10.3847/1538-4357/ac7f2d",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2022-08-01",
"series_number": "2",
"volume": "935",
"issue": "2",
"pages": "89"
},
{
"id": "authors:91v8z-6wm14",
"collection": "authors",
"collection_id": "91v8z-6wm14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220728-730128000",
"type": "article",
"title": "The COS Legacy Archive Spectroscopy Survey (CLASSY) Treasury Atlas",
"author": [
{
"family_name": "Berg",
"given_name": "Danielle A.",
"orcid": "0000-0002-4153-053X",
"clpid": "Berg-Danielle-A"
},
{
"family_name": "James",
"given_name": "Bethan L.",
"orcid": "0000-0003-4372-2006"
},
{
"family_name": "King",
"given_name": "Teagan",
"orcid": "0000-0003-0834-4150"
},
{
"family_name": "McDonald",
"given_name": "Meaghan",
"orcid": "0000-0003-0557-3433"
},
{
"family_name": "Chen",
"given_name": "Zuyi",
"orcid": "0000-0002-2178-5471"
},
{
"family_name": "Chisholm",
"given_name": "John",
"orcid": "0000-0002-0302-2577"
},
{
"family_name": "Heckman",
"given_name": "Timothy",
"orcid": "0000-0001-6670-6370"
},
{
"family_name": "Martin",
"given_name": "Crystal L.",
"orcid": "0000-0001-9189-7818"
},
{
"family_name": "Stark",
"given_name": "Dan P.",
"orcid": "0000-0001-6106-5172"
},
{
"family_name": "Aloisi",
"given_name": "Alessandra",
"orcid": "0000-0003-4137-882X"
},
{
"family_name": "Amor\u00edn",
"given_name": "Ricardo O.",
"orcid": "0000-0001-5758-1000"
},
{
"family_name": "Arellano-C\u00f3rdova",
"given_name": "Karla Z.",
"orcid": "0000-0003-2589-762X"
},
{
"family_name": "Bayliss",
"given_name": "Matthew",
"orcid": "0000-0003-1074-4807"
},
{
"family_name": "Bordoloi",
"given_name": "Rongmon",
"orcid": "0000-0002-3120-7173"
},
{
"family_name": "Brinchmann",
"given_name": "Jarle",
"orcid": "0000-0003-4359-8797"
},
{
"family_name": "Charlot",
"given_name": "St\u00e9phane",
"orcid": "0000-0003-3458-2275"
},
{
"family_name": "Chevallard",
"given_name": "Jacopo",
"orcid": "0000-0002-7636-0534"
},
{
"family_name": "Clark",
"given_name": "Ilyse",
"orcid": "0000-0003-3334-4267"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758"
},
{
"family_name": "Feltre",
"given_name": "Anna",
"orcid": "0000-0001-6865-2871"
},
{
"family_name": "Gronke",
"given_name": "Max",
"orcid": "0000-0003-2491-060X"
},
{
"family_name": "Hayes",
"given_name": "Matthew",
"orcid": "0000-0001-8587-218X"
},
{
"family_name": "Henry",
"given_name": "Alaina",
"orcid": "0000-0002-6586-4446"
},
{
"family_name": "Hernandez",
"given_name": "Svea",
"orcid": "0000-0003-4857-8699"
},
{
"family_name": "Jaskot",
"given_name": "Anne",
"orcid": "0000-0002-6790-5125"
},
{
"family_name": "Jones",
"given_name": "Tucker",
"orcid": "0000-0001-5860-3419"
},
{
"family_name": "Kewley",
"given_name": "Lisa J.",
"orcid": "0000-0001-8152-3943"
},
{
"family_name": "Kumari",
"given_name": "Nimisha",
"orcid": "0000-0002-5320-2568"
},
{
"family_name": "Leitherer",
"given_name": "Claus",
"orcid": "0000-0003-2685-4488"
},
{
"family_name": "Llerena",
"given_name": "Mario",
"orcid": "0000-0003-1354-4296"
},
{
"family_name": "Maseda",
"given_name": "Michael",
"orcid": "0000-0003-0695-4414"
},
{
"family_name": "Nanayakkara",
"given_name": "Themiya",
"orcid": "0000-0003-2804-0648"
},
{
"family_name": "Ouchi",
"given_name": "Masami",
"orcid": "0000-0002-1049-6658"
},
{
"family_name": "Plat",
"given_name": "Adele",
"orcid": "0000-0003-0390-0656"
},
{
"family_name": "Pogge",
"given_name": "Richard W.",
"orcid": "0000-0003-1435-3053"
},
{
"family_name": "Ravindranath",
"given_name": "Swara",
"orcid": "0000-0002-5269-6527"
},
{
"family_name": "Rigby",
"given_name": "Jane R.",
"orcid": "0000-0002-7627-6551"
},
{
"family_name": "Sanders",
"given_name": "Ryan",
"orcid": "0000-0003-4792-9119"
},
{
"family_name": "Scarlata",
"given_name": "Claudia",
"orcid": "0000-0002-9136-8876"
},
{
"family_name": "Senchyna",
"given_name": "Peter",
"orcid": "0000-0002-9132-6561"
},
{
"family_name": "Skillman",
"given_name": "Evan D.",
"orcid": "0000-0003-0605-8732"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636"
},
{
"family_name": "Sugahara",
"given_name": "Yuma",
"orcid": "0000-0001-6958-7856"
},
{
"family_name": "Wilkins",
"given_name": "Stephen M.",
"orcid": "0000-0003-3903-6935"
},
{
"family_name": "Wofford",
"given_name": "Aida",
"orcid": "0000-0001-8289-3428"
},
{
"family_name": "Xu",
"given_name": "Xinfeng",
"orcid": "0000-0002-9217-7051"
},
{
"literal": "CLASSY Team"
}
],
"abstract": "Far-ultraviolet (FUV; \u223c1200\u20132000 \u00c5) spectra are fundamental to our understanding of star-forming galaxies, providing a unique window on massive stellar populations, chemical evolution, feedback processes, and reionization. The launch of the James Webb Space Telescope will soon usher in a new era, pushing the UV spectroscopic frontier to higher redshifts than ever before; however, its success hinges on a comprehensive understanding of the massive star populations and gas conditions that power the observed UV spectral features. This requires a level of detail that is only possible with a combination of ample wavelength coverage, signal-to-noise, spectral-resolution, and sample diversity that has not yet been achieved by any FUV spectral database. We present the Cosmic Origins Spectrograph Legacy Spectroscopic Survey (CLASSY) treasury and its first high-level science product, the CLASSY atlas. CLASSY builds on the Hubble Space Telescope (HST) archive to construct the first high-quality (S/N_(1500 \u00c5) \u2273 5/resel), high-resolution (R \u223c 15,000) FUV spectral database of 45 nearby (0.002 z M_\u22c6(M_\u2299)) M_\u2299 yr\u207b\u00b9) < +1.6), direct gas-phase metallicity (7.0 < 12 + log(O/H) < 8.8), ionization (0.5 < O\u2083\u2082 < 38.0), reddening (0.02 < E(B \u2212 V) < 0.67), and nebular density (10 < n\u2091 (cm\u207b\u00b3) < 1120). CLASSY is biased to UV-bright star-forming galaxies, resulting in a sample that is consistent with the z \u223c 0 mass\u2013metallicity relationship, but is offset to higher star formation rates by roughly 2 dex, similar to z \u2273 2 galaxies. This unique set of properties makes the CLASSY atlas the benchmark training set for star-forming galaxies across cosmic time.",
"doi": "10.3847/1538-4365/ac6c03",
"issn": "0067-0049",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Supplement Series",
"publication_date": "2022-08",
"series_number": "2",
"volume": "261",
"issue": "2",
"pages": "Art. No. 31"
},
{
"id": "authors:2wdj2-v8v82",
"collection": "authors",
"collection_id": "2wdj2-v8v82",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220727-38096000",
"type": "article",
"title": "CLASSY III. The Properties of Starburst-driven Warm Ionized Outflows",
"author": [
{
"family_name": "Xu",
"given_name": "Xinfeng",
"orcid": "0000-0002-9217-7051",
"clpid": "Xu-Xinfeng"
},
{
"family_name": "Heckman",
"given_name": "Timothy",
"orcid": "0000-0001-6670-6370",
"clpid": "Heckman-Timothy-M"
},
{
"family_name": "Henry",
"given_name": "Alaina",
"orcid": "0000-0002-6586-4446",
"clpid": "Henry-Alaina-L"
},
{
"family_name": "Berg",
"given_name": "Danielle A.",
"orcid": "0000-0002-4153-053X",
"clpid": "Berg-Danielle-A"
},
{
"family_name": "Chisholm",
"given_name": "John",
"orcid": "0000-0002-0302-2577",
"clpid": "Chisholm-John"
},
{
"family_name": "James",
"given_name": "Bethan L.",
"orcid": "0000-0003-4372-2006",
"clpid": "James-Bethan-L"
},
{
"family_name": "Martin",
"given_name": "Crystal L.",
"orcid": "0000-0001-9189-7818",
"clpid": "Martin-Crystal-L"
},
{
"family_name": "Stark",
"given_name": "Daniel P.",
"orcid": "0000-0001-6106-5172",
"clpid": "Stark-Daniel-P"
},
{
"family_name": "Aloisi",
"given_name": "Alessandra",
"orcid": "0000-0003-4137-882X",
"clpid": "Aloisi-Alessandra"
},
{
"family_name": "Amor\u00edn",
"given_name": "Ricardo O.",
"orcid": "0000-0001-5758-1000",
"clpid": "Amor\u00edn-Ricardo-O"
},
{
"family_name": "Arellano-C\u00f3rdova",
"given_name": "Karla Z.",
"orcid": "0000-0003-2589-762X",
"clpid": "Arellano-C\u00f3rdova-Karla-Z"
},
{
"family_name": "Bordoloi",
"given_name": "Rongmon",
"orcid": "0000-0002-3120-7173",
"clpid": "Bordoloi-Rongmon"
},
{
"family_name": "Charlot",
"given_name": "St\u00e9phane",
"orcid": "0000-0003-3458-2275",
"clpid": "Chrlot-St\u00e9phane"
},
{
"family_name": "Chen",
"given_name": "Zuyi",
"orcid": "0000-0002-2178-5471",
"clpid": "Chen-Zuyi"
},
{
"family_name": "Hayes",
"given_name": "Matthew",
"orcid": "0000-0001-8587-218X",
"clpid": "Hayes-Matthew"
},
{
"family_name": "Sugahara",
"given_name": "Yuma",
"orcid": "0000-0001-6958-7856",
"clpid": "Sugahara-Yuma"
},
{
"family_name": "Kewley",
"given_name": "Lisa J.",
"orcid": "0000-0001-8152-3943",
"clpid": "Kewley-Lisa-J"
},
{
"family_name": "Ouchi",
"given_name": "Masami",
"orcid": "0000-0002-1049-6658",
"clpid": "Ouchi-Masami"
},
{
"family_name": "Scarlata",
"given_name": "Claudia",
"orcid": "0000-0002-9136-8876",
"clpid": "Scarlata-Claudia-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We report the results of analyses of galactic outflows in a sample of 45 low-redshift starburst galaxies in the COS Legacy Archive Spectroscopic SurveY (CLASSY), augmented by five additional similar starbursts with Cosmic Origins Spectrograph (COS) data. The outflows are traced by blueshifted absorption lines of metals spanning a wide range of ionization potential. The high quality and broad spectral coverage of CLASSY data enable us to disentangle the absorption due to the static interstellar medium (ISM) from that due to outflows. We further use different line multiplets and doublets to determine the covering fraction, column density, and ionization state as a function of velocity for each outflow. We measure the outflow's mean velocity and velocity width, and find that both correlate in a highly significant way with the star formation rate, galaxy mass, and circular velocity over ranges of four orders of magnitude for the first two properties. We also estimate outflow rates of metals, mass, momentum, and kinetic energy. We find that, at most, only about 20% of silicon created and ejected by supernovae in the starburst is carried out in the warm phase we observe. The outflows' mass-loading factor increases steeply and inversely with both circular and outflow velocity (log\u2013log slope \u223c\u22121.6), and reaches \u223c10 for dwarf galaxies. We find that the outflows typically carry about 10%\u2013100% of the momentum injected by massive stars and about 1%\u201320% of the kinetic energy. We show that these results place interesting constraints on, and new insights into, models and simulations of galactic winds.",
"doi": "10.3847/1538-4357/ac6d56",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2022-07-10",
"series_number": "2",
"volume": "933",
"issue": "2",
"pages": "Art. No. 222"
},
{
"id": "authors:9dmga-rhb38",
"collection": "authors",
"collection_id": "9dmga-rhb38",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210825-184654591",
"type": "article",
"title": "Where outflows meet inflows: gas kinematics in SSA22 Ly \u03b1 blob 2 decoded by advanced radiative transfer modelling",
"author": [
{
"family_name": "Li",
"given_name": "Zhihui",
"orcid": "0000-0001-5113-7558",
"clpid": "Li-Zhihui"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Gronke",
"given_name": "Max",
"orcid": "0000-0003-2491-060X",
"clpid": "Gronke-Max"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"orcid": "0000-0003-1747-2891",
"clpid": "Matsuda-Yuichi"
}
],
"abstract": "We present new spectroscopic observations of Ly \u03b1 (Ly \u03b1) Blob 2 (z \u223c 3.1). We observed extended Ly \u03b1 emission in three distinct regions, where the highest Ly \u03b1 surface brightness (SB) centre is far away from the known continuum sources. We searched through the MOSFIRE slits that cover the high Ly \u03b1 SB regions, but were unable to detect any significant nebular emission near the highest SB centre. We further mapped the flux ratio of the blue peak to the red peak and found it is anticorrelated with Ly \u03b1 SB with a power-law index of \u223c \u20130.4. We used radiative transfer models with both multiphase, clumpy, and shell geometries and successfully reproduced the diverse Ly \u03b1 morphologies. We found that most spectra suggest outflow-dominated kinematics, while 4/15 spectra imply inflows. A significant correlation exists between parameter pairs, and the multiphase, clumpy model may alleviate previously reported discrepancies. We also modelled Ly \u03b1 spectra at different positions simultaneously and found that the variation of the inferred clump outflow velocities can be approximately explained by line-of-sight projection effects. Our results support the 'central powering + scattering' scenario, i.e. the Ly \u03b1 photons are generated by a central powering source and then scatter with outflowing, multiphase H\u2009 I gas while propagating outwards. The infalling of cool gas near the blob outskirts shapes the observed blue-dominated Ly \u03b1 profiles, but its energy contribution to the total Ly \u03b1 luminosity is less than 10 per\u2009cent, i.e. minor compared to the photoionization by star-forming galaxies and/or AGNs.",
"doi": "10.1093/mnras/stac958",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2022-07",
"series_number": "3",
"volume": "513",
"issue": "3",
"pages": "3414-3428"
},
{
"id": "authors:4pn50-77y72",
"collection": "authors",
"collection_id": "4pn50-77y72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220802-742857000",
"type": "article",
"title": "Reconciling the results of the z \u223c 2 MOSDEF and KBSS-MOSFIRE Surveys",
"author": [
{
"family_name": "Runco",
"given_name": "Jordan N.",
"orcid": "0000-0003-4852-8958",
"clpid": "Runco-Jordan-N"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-Naveen-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-Alice-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Sanders",
"given_name": "Ryan L.",
"orcid": "0000-0003-4792-9119",
"clpid": "Sanders-Ryan-L"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-Allison-L"
},
{
"family_name": "Coil",
"given_name": "Alison L.",
"orcid": "0000-0002-2583-5894",
"clpid": "Coil-Alison-L"
},
{
"family_name": "Kriek",
"given_name": "Mariska",
"orcid": "0000-0002-7613-9872",
"clpid": "Kriek-Mariska"
},
{
"family_name": "Mobasher",
"given_name": "Bahram",
"clpid": "Mobasher-Bahram"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-Max"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-Gwen-C"
},
{
"family_name": "Siana",
"given_name": "Brian",
"orcid": "0000-0002-4935-9511",
"clpid": "Siana-Brian-D"
},
{
"family_name": "Topping",
"given_name": "Michael W.",
"orcid": "0000-0001-8426-1141",
"clpid": "Topping-Michael-W"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-Ryan-F"
},
{
"family_name": "Freeman",
"given_name": "William R.",
"orcid": "0000-0003-3559-5270",
"clpid": "Freeman-William-R"
},
{
"family_name": "Shivaei",
"given_name": "Irene",
"orcid": "0000-0003-4702-7561",
"clpid": "Shivaei-Irene"
},
{
"family_name": "Azadi",
"given_name": "Mojegan",
"orcid": "0000-0001-6004-9728",
"clpid": "Azadi-Mojegan"
},
{
"family_name": "Price",
"given_name": "Sedona H.",
"orcid": "0000-0002-0108-4176",
"clpid": "Price-Sedona-H"
},
{
"family_name": "Leung",
"given_name": "Gene C. K.",
"orcid": "0000-0002-9393-6507",
"clpid": "Leung-Gene-C-K"
},
{
"family_name": "Fetherolf",
"given_name": "Tara",
"orcid": "0000-0002-3551-279X",
"clpid": "Fetherolf-Tara"
},
{
"family_name": "de\u00a0Groot",
"given_name": "Laura",
"clpid": "de-Groot-Laura"
},
{
"family_name": "Zick",
"given_name": "Tom",
"clpid": "Zick-Tom"
},
{
"family_name": "Fornasini",
"given_name": "Francesca M.",
"orcid": "0000-0002-9286-9963",
"clpid": "Fornasini-Francesca-M"
},
{
"family_name": "Barro",
"given_name": "Guillermo",
"orcid": "0000-0001-6813-875X",
"clpid": "Barro-Guillermo"
}
],
"abstract": "The combination of the MOSDEF and KBSS-MOSFIRE surveys represents the largest joint investment of Keck/MOSFIRE time to date, with \u223c3000 galaxies at 1.4 \u2272 z \u2272 3.8, roughly half of which are at z \u223c 2. MOSDEF is photometric- and spectroscopic-redshift selected with a rest-optical magnitude limit, while KBSS-MOSFIRE is primarily selected based on rest-UV colours and a rest-UV magnitude limit. Analysing both surveys in a uniform manner with consistent spectral-energy-distribution (SED) models, we find that the MOSDEF z \u223c 2 targeted sample has higher median M* and redder rest U\u2212V colour than the KBSS-MOSFIRE z \u223c 2 targeted sample, and smaller median SED-based SFR and sSFR (SFR(SED) and sSFR(SED)). Specifically, MOSDEF targeted a larger population of red galaxies with U\u2212V and V\u2212J \u22651.25, while KBSS-MOSFIRE contains more young galaxies with intense star formation. Despite these differences in the z \u223c 2 targeted samples, the subsets of the surveys with multiple emission lines detected and analysed in previous work are much more similar. All median host-galaxy properties with the exception of stellar population age \u2013 i.e. M*, SFR(SED), sSFR(SED), AV, and UVJ colours \u2013 agree within the uncertainties. Additionally, when uniform emission-line fitting and stellar Balmer absorption correction techniques are applied, there is no significant offset between both samples in the [O\u2009iii]\u03bb5008/H\u2009\u03b2 versus [N\u2009ii]\u03bb6585/H\u2009\u03b1 diagnostic diagram, in contrast to previously reported discrepancies. We can now combine the MOSDEF and KBSS-MOSFIRE surveys to form the largest z \u223c 2 sample with moderate-resolution rest-optical spectra and construct the fundamental scaling relations of star-forming galaxies during this important epoch.",
"doi": "10.1093/mnras/stac1115",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2022-07",
"series_number": "3",
"volume": "513",
"issue": "3",
"pages": "3871-3892"
},
{
"id": "authors:e6nbf-yb608",
"collection": "authors",
"collection_id": "e6nbf-yb608",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220307-189105000",
"type": "article",
"title": "Empirical Constraints on Core-collapse Supernova Yields Using Very Metal-poor Damped Ly\u03b1 Absorbers",
"author": [
{
"family_name": "Nu\u00f1ez",
"given_name": "Evan H.",
"orcid": "0000-0001-5595-757X",
"clpid": "Nu\u00f1ez-Evan-H"
},
{
"family_name": "Kirby",
"given_name": "Evan N.",
"orcid": "0000-0001-6196-5162",
"clpid": "Kirby-E-N"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We place empirical constraints on the yields from zero- and low-metallicity core-collapse supernovae (CCSNe) using abundances measured in very metal-poor (VMP; [Fe/H] \u2264 \u22122) damped Ly\u03b1 absorbers (DLAs). For some abundance ratios ([N,Al,S/Fe]), VMP DLAs constrain the metal yields of the first SNe more reliably than VMP stars. We compile a large sample of high-S/N VMP DLAs from over 30 yr of literature, most with high-resolution spectral measurements. We infer the initial-mass-function-averaged CCSNe yield from the median values from the DLA abundance ratios of C, N, O, Al, Si, S, and Fe (over Fe and O). We assume that the DLAs are metal-poor enough that they represent galaxies in their earliest stages of evolution, when CCSNe are the only nucleosynthetic sources of the metals we analyze. We compare five sets of zero- and low-metallicity theoretical yields to the empirical yields derived in this work. We find that the five models agree with the DLA yields for ratios containing Si and S. Only one model (Heger & Woosley 2010, hereafter HW10) reproduced the DLA values for N, and one other model (Limongi & Chieffi 2018, hereafter LC18) reproduced [N/O]. We found little change in the theoretical yields with the adoption of an SN explosion landscape (where certain progenitor masses collapse into black holes, contributing no yields) onto HW10, but fixing explosion energy to progenitor mass results in wide disagreements between the predictions and DLA abundances. We investigate the adoption of a simple, observationally motivated initial distribution of rotational velocities for LC18 and find a slight improvement.",
"doi": "10.3847/1538-4357/ac470e",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2022-03-01",
"series_number": "1",
"volume": "927",
"issue": "1",
"pages": "Art. No. 64"
},
{
"id": "authors:ybnrp-k4s60",
"collection": "authors",
"collection_id": "ybnrp-k4s60",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220209-266204000",
"type": "article",
"title": "The Effects of Stellar Population and Gas Covering Fraction on the Emergent Ly\u03b1 Emission of High-redshift Galaxies",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-Naveen-A"
},
{
"family_name": "Topping",
"given_name": "Michael W.",
"clpid": "Topping-Michael-W"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-Alice-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Sanders",
"given_name": "Ryan L.",
"orcid": "0000-0003-4792-9119",
"clpid": "Sanders-Ryan-L"
},
{
"family_name": "Du",
"given_name": "Xinnan",
"orcid": "0000-0001-5554-5444",
"clpid": "Du-Xinnan"
},
{
"family_name": "Coil",
"given_name": "Alison L.",
"orcid": "0000-0002-2583-5894",
"clpid": "Coil-Alison-L"
},
{
"family_name": "Mobasher",
"given_name": "Bahram",
"clpid": "Mobasher-Bahram"
},
{
"family_name": "Price",
"given_name": "Sedona H.",
"orcid": "0000-0002-0108-4176",
"clpid": "Price-Sedona-H"
},
{
"family_name": "Shivaei",
"given_name": "Irene",
"orcid": "0000-0003-4702-7561",
"clpid": "Shivaei-Irene"
}
],
"abstract": "We perform joint modeling of the composite rest-frame far-UV and optical spectra of redshift 1.85 \u2264 z \u2264 3.49 star-forming galaxies to deduce key properties of the massive stars, ionized interstellar medium (ISM), and neutral ISM, with the aim of investigating the principal factors affecting the production and escape of Ly\u03b1 photons. Our sample consists of 136 galaxies with deep Keck/LRIS and MOSFIRE spectra covering, respectively, Ly\u03b2 through C iii] \u03bb\u03bb1907, 1909 and [O ii], [Ne iii], H\u03b2, [O iii], H\u03b1, [N ii], and [S ii]. Spectral and photoionization modeling indicates that the galaxies are uniformly consistent with stellar population synthesis models that include the effects of stellar binarity. Over the dynamic range of our sample, there is little variation in stellar and nebular abundance with Ly\u03b1 equivalent width, W_\u03bb(Ly\u03b1), and only a marginal anticorrelation between age and W_\u03bb(Ly\u03b1). The inferred range of ionizing spectral shapes is insufficient to solely account for the variation in W_\u03bb(Ly\u03b1); rather, the covering fraction of optically thick H i appears to be the principal factor modulating the escape of Ly\u03b1, with most of the Ly\u03b1 photons in down-the-barrel observations of galaxies escaping through low column density or ionized channels in the ISM. Our analysis shows that a high star-formation-rate surface density, \u03a3_(SFR), particularly when coupled with a low galaxy potential (i.e., low stellar mass), can aid in reducing the covering fraction and ease the escape of Ly\u03b1 photons. We conclude with a discussion of the implications of our results for the escape of ionizing radiation at high redshift.",
"doi": "10.3847/1538-4357/ac3b4c",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2022-02-10",
"series_number": "1",
"volume": "926",
"issue": "1",
"pages": "Art. No. 31"
},
{
"id": "authors:7rgwn-p8n07",
"collection": "authors",
"collection_id": "7rgwn-p8n07",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220203-318352000",
"type": "article",
"title": "Chemical Abundance Scaling Relations for Multiple Elements in z \u2243 2\u20133 Star-forming Galaxies",
"author": [
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-Allison-L"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-Gwen-C"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-Ryan-F"
}
],
"abstract": "The chemical abundance patterns of gas and stars in galaxies are powerful probes of galaxies' star formation histories and the astrophysics of galaxy assembly but are challenging to measure with confidence in distant galaxies. In this paper, we report the first measurements of the correlation between stellar mass (M_*) and multiple tracers of chemical enrichment (including O, N, and Fe) in individual z \u223c 2\u20133 galaxies, using a sample of 195 star-forming galaxies from the Keck Baryonic Structure Survey. The galaxies' chemical abundances are inferred using photoionization models capable of reconciling high-redshift galaxies' observed extreme rest-UV and rest-optical spectroscopic properties. We find that the M_*\u2013O/H relation for our sample is relatively shallow, with moderately large scatter, and is offset \u223c0.35 dex higher than the corresponding M_*\u2013Fe/H relation. The two relations have very similar slopes, indicating a high level of \u03b1-enhancement\u2014O/Fe \u2248 2.2 \u00d7 (O/Fe)_\u2299\u2014across two decades in M_*. The M_*\u2013N/H relation has the steepest slope and largest intrinsic scatter, which likely results from the fact that many z \u223c 2 galaxies are observed near or past the transition from \"primary\" to \"secondary\" N production, and may reflect uncertainties in the astrophysical origin of N. Together, these results suggest that z \u223c 2 galaxies are old enough to have seen substantial enrichment from intermediate-mass stars, but are still young enough that Type Ia supernovae have not had time to contribute significantly to their enrichment.",
"doi": "10.3847/1538-4357/ac38a3",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2022-02-01",
"series_number": "2",
"volume": "925",
"issue": "2",
"pages": "Art. No. 116"
},
{
"id": "authors:9ctyx-2jw96",
"collection": "authors",
"collection_id": "9ctyx-2jw96",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210825-184651133",
"type": "article",
"title": "The KBSS\u2013KCWI survey: the connection between extended Ly\u2009\u03b1 haloes and galaxy azimuthal angle at z \u223c 2\u20133",
"author": [
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-Dawn-K"
},
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-David-R"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-Ryan-F"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-Naveen-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-Alice-E"
},
{
"family_name": "Pahl",
"given_name": "Anthony J.",
"orcid": "0000-0003-4464-4505",
"clpid": "Pahl-Anthony-J"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-Allison-L"
},
{
"family_name": "Lamb",
"given_name": "Noah R.",
"orcid": "0000-0002-2052-822X",
"clpid": "Lamb-Noah-R"
},
{
"family_name": "Li",
"given_name": "Zhihui",
"orcid": "0000-0001-5113-7558",
"clpid": "Li-Zhihui"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-Gwen-C"
}
],
"abstract": "We present the first statistical analysis of kinematically resolved, spatially extended Ly\u03b1 emission around z = 2\u20133 galaxies in the Keck Baryonic Structure Survey (KBSS) using the Keck Cosmic Web Imager (KCWI). Our sample of 59 star-forming galaxies (z_(med) = 2.29) comprises the subset with typical KCWI integration times of \u223c5 h and with existing imaging data from the Hubble Space Telescope and/or adaptive optics-assisted integral field spectroscopy. The high-resolution images were used to evaluate the azimuthal dependence of the diffuse Ly\u03b1 emission with respect to the stellar continuum within projected galactocentric distances of \u227230 proper kpc. We introduce cylindrically projected 2D spectra (CP2D) that map the averaged Ly\u03b1 spectral profile over a specified range of azimuthal angle, as a function of impact parameter around galaxies. The averaged CP2D spectrum of all galaxies shows clear signatures of Ly\u03b1 resonant scattering by outflowing gas. We stacked the CP2D spectra of individual galaxies over ranges of azimuthal angle with respect to their major axes. The extended Ly\u03b1 emission along the galaxy principal axes is statistically indistinguishable, with residual asymmetry of \u22642 per\u2009cent (\u223c2\u03c3) of the integrated Ly\u03b1 emission. The symmetry implies that the Ly\u03b1 scattering medium is dominated by outflows in all directions within 30 kpc. Meanwhile, we find that the blueshifted component of Ly\u03b1 emission is marginally stronger along galaxy minor axes for galaxies with relatively weak Ly\u03b1 emission. We speculate that this weak directional dependence of Ly\u03b1 emission becomes discernible only when the Ly\u03b1 escape fraction is low. These discoveries highlight the need for similar analyses in simulations with Ly\u03b1 radiative transfer modelling.",
"doi": "10.1093/mnras/stab2383",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2021-11",
"series_number": "1",
"volume": "508",
"issue": "1",
"pages": "19-43"
},
{
"id": "authors:0m2tq-aec75",
"collection": "authors",
"collection_id": "0m2tq-aec75",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211011-195252309",
"type": "article",
"title": "A Massive Quiescent Galaxy Confirmed in a Protocluster at z = 3.09",
"author": [
{
"family_name": "Kubo",
"given_name": "Mariko",
"orcid": "0000-0002-7598-5292",
"clpid": "Kubo-Mariko"
},
{
"family_name": "Umehata",
"given_name": "Hideki",
"orcid": "0000-0003-1937-0573",
"clpid": "Umehata-Hideki"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"orcid": "0000-0003-1747-2891",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Kajisawa",
"given_name": "Masaru",
"orcid": "0000-0002-1732-6387",
"clpid": "Kajisawa-Masaru"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Yamada",
"given_name": "Toru",
"clpid": "Yamada-Toru"
},
{
"family_name": "Tanaka",
"given_name": "Ichi",
"orcid": "0000-0002-4937-4738",
"clpid": "Tanaka-Ichi"
},
{
"family_name": "Hatsukade",
"given_name": "Bunyo",
"orcid": "0000-0001-6469-8725",
"clpid": "Hatsukade-Bunyo"
},
{
"family_name": "Tamura",
"given_name": "Yoichi",
"orcid": "0000-0003-4807-8117",
"clpid": "Tamura-Yoichi"
},
{
"family_name": "Nakanishi",
"given_name": "Kouichiro",
"orcid": "0000-0002-6939-0372",
"clpid": "Nakanishi-Kouichiro"
},
{
"family_name": "Kohno",
"given_name": "Kotaro",
"orcid": "0000-0002-4052-2394",
"clpid": "Kohno-Kotaro"
},
{
"family_name": "Lee",
"given_name": "Kianhong",
"orcid": "0000-0003-4814-0101",
"clpid": "Lee-Kianhong"
},
{
"family_name": "Matsuda",
"given_name": "Keiichi",
"clpid": "Matsuda-Keiichi"
}
],
"abstract": "We report a massive quiescent galaxy at z_(spec) = 3.0922^(+0.008)_(\u22120.004) spectroscopically confirmed at a protocluster in the SSA22 field by detecting the Balmer and Ca II absorption features with the multi-object spectrometer for infrared exploration on the Keck I telescope. This is the most distant quiescent galaxy confirmed in a protocluster to date. We fit the optical to mid-infrared photometry and spectrum simultaneously with spectral energy distribution (SED) models of parametric and nonparametric star formation histories (SFHs). Both models fit the observed SED well and confirm that this object is a massive quiescent galaxy with a stellar mass of log(M\u22c6/M_\u2299) = 11.26^(+0.03)_(\u22120.04) and 11.54^(+0.03)_(\u22120.00), and a star formation rate of SFR/M_\u2299 yr\u207b\u00b9 < 0.3 and = 0.01^(+0.03)_(\u22120.01) for parametric and nonparametric models, respectively. The SFH from the former modeling is described as an instantaneous starburst whereas that of the latter modeling is longer-lived, but both models agree with a sudden quenching of the star formation at \u223c0.6 Gyr ago. This massive quiescent galaxy is confirmed in an extremely dense group of galaxies predicted as a progenitor of a brightest cluster galaxy formed via multiple mergers in cosmological numerical simulations. We discover three new plausible [O III]\u03bb5007 emitters at 3.0791 \u2264 z_(spec) \u2264 3.0833 serendipitously detected around the target. Two of them just between the target and its nearest massive galaxy are possible evidence of their interactions. They suggest the future great size and stellar mass evolution of this massive quiescent galaxy via mergers.",
"doi": "10.3847/1538-4357/ac0cf8",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2021-09-20",
"series_number": "1",
"volume": "919",
"issue": "1",
"pages": "Art. No. 6"
},
{
"id": "authors:eth6n-fq102",
"collection": "authors",
"collection_id": "eth6n-fq102",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210914-225410693",
"type": "article",
"title": "ALMA Observations of Ly\u03b1 Blob 1: Multiple Major Mergers and Widely Distributed Interstellar Media",
"author": [
{
"family_name": "Umehata",
"given_name": "Hideki",
"orcid": "0000-0003-1937-0573",
"clpid": "Umehata-Hideki"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Hayes",
"given_name": "Matthew",
"orcid": "0000-0001-8587-218X",
"clpid": "Hayes-Matthew"
},
{
"family_name": "Scott",
"given_name": "Douglas",
"orcid": "0000-0002-6878-9840",
"clpid": "Scott-Douglas"
},
{
"family_name": "Swinbank",
"given_name": "A. M.",
"orcid": "0000-0003-1192-5837",
"clpid": "Swinbank-A-Mark"
},
{
"family_name": "Ivison",
"given_name": "R. J.",
"orcid": "0000-0001-5118-1313",
"clpid": "Ivison-Rob-J"
},
{
"family_name": "Nagao",
"given_name": "Toru",
"clpid": "Nagao-Toru"
},
{
"family_name": "Kubo",
"given_name": "Mariko",
"orcid": "0000-0002-7598-5292",
"clpid": "Kubo-Mariko"
},
{
"family_name": "Nakanishi",
"given_name": "Kouichiro",
"orcid": "0000-0002-6939-0372",
"clpid": "Nakanishi-Kouichiro"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"orcid": "0000-0003-1747-2891",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Ikarashi",
"given_name": "Soh",
"clpid": "Ikarashi-Soh"
},
{
"family_name": "Tamura",
"given_name": "Yoichi",
"orcid": "0000-0003-4807-8117",
"clpid": "Tamura-Yoichi"
},
{
"family_name": "Geach",
"given_name": "J. E.",
"orcid": "0000-0003-4964-4635",
"clpid": "Geach-James-E"
}
],
"abstract": "We present observations of a giant Ly\u03b1 blob (LAB) in the SSA22 protocluster at z = 3.1, SSA22-LAB1, taken with the Atacama Large Millimeter/submillimeter Array. Dust continuum, along with [C ii] 158 \u03bcm and CO(4\u20133) line emission have been detected in LAB1, showing complex morphology and kinematics across a \u223c100 kpc central region. Seven galaxies at z = 3.0987\u20133.1016 in the surroundings are identified in [C ii] and dust continuum emission, with two of them potential companions or tidal structures associated with the most massive galaxies. Spatially resolved [C ii] and infrared luminosity ratios for the widely distributed media (L_[C\u026a\u026a]/L_(IR) \u2248 10\u207b\u00b2\u221210\u207b\u00b3) suggest that the observed extended interstellar media are likely to have originated from star formation activity and the contribution from shocked gas is probably not dominant. LAB1 is found to harbor a total molecular gas mass M_(mol) = (8.7 \u00b1 2.0) \u00d7 10\u00b9\u2070 M_\u2299, concentrated in the core region of the Ly\u03b1-emitting area. While (primarily obscured) star formation activity in the LAB1 core is one of the most plausible power sources for the Ly\u03b1 emission, multiple major mergers found in the core may also play a role in making LAB1 exceptionally bright and extended in Ly\u03b1 as a result of cooling radiation induced by gravitational interactions.",
"doi": "10.3847/1538-4357/ac1106",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2021-09-10",
"series_number": "2",
"volume": "918",
"issue": "2",
"pages": "Art. No. 69"
},
{
"id": "authors:2n4cj-13937",
"collection": "authors",
"collection_id": "2n4cj-13937",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210821-170423382",
"type": "article",
"title": "An uncontaminated measurement of the escaping Lyman continuum at z \u223c 3",
"author": [
{
"family_name": "Pahl",
"given_name": "Anthony J.",
"orcid": "0000-0003-4464-4505",
"clpid": "Pahl-Anthony-J"
},
{
"family_name": "Shapley",
"given_name": "Alice",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-Alice-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-Naveen-A"
}
],
"abstract": "Observations of reionization-era analogues at z \u223c 3 are a powerful tool for constraining reionization. Rest-ultraviolet observations are particularly useful, in which both direct and indirect tracers of ionizing-photon production and escape can be observed. We analyse a sample of 124 z \u223c 3 galaxies from the Keck Lyman Continuum Spectroscopic Survey, with sensitive spectroscopic measurements of the Lyman continuum region. We present a method of removing foreground contamination from our sample using high-resolution, multiband Hubble Space Telescope imaging. We re-measure the global properties of the cleaned sample of 13 individually detected Lyman continuum sources and 107 individually undetected sources, including a sample-averaged absolute escape fraction of f_(esc, abs) = 0.06 \u00b1 0.01 and a sample-averaged ratio of ionizing to non-ionizing ultraviolet flux density of \u3008f\u2089\u2080\u2080/f\u2081\u2085\u2080\u2080\u3009_(out) = 0.040 \u00b1 0.006, corrected for attenuation from the intergalactic and circumgalactic media. Based on composite spectra, we also recover a strong positive correlation between \u3008f\u2089\u2080\u2080/f\u2081\u2085\u2080\u2080\u3009_(out) and Ly\u03b1 equivalent width (W_\u03bb(Ly\u03b1\u2060)) and a negative correlation between \u3008f\u2089\u2080\u2080/f\u2081\u2085\u2080\u2080\u3009_(out) and UV luminosity. As in previous work, we interpret the relationship between \u3008f\u2089\u2080\u2080/f\u2081\u2085\u2080\u2080\u3009_(out) and W_\u03bb(Ly\u03b1\u2060) in terms of the modulation of the escape of ionizing radiation from star-forming galaxies based on the covering fraction of neutral gas. We also use a W_\u03bb(Ly\u03b1\u2060)-weighted \u3008f\u2089\u2080\u2080/f\u2081\u2085\u2080\u2080\u3009_(out) to estimate an ionizing emissivity from star-forming galaxies at z \u223c 3 as \u03f5_(LyC) \u2243 5.5 \u00d7 10\u00b2\u2074 erg\u2009s\u207b\u00b9\u2009Hz\u207b\u00b9\u2009Mpc\u207b\u00b3. This estimate, evaluated using the uncontaminated sample of this work, affirms that the contribution of galaxies to the ionizing background at z \u223c 3 is comparable to that of active galactic nuclei.",
"doi": "10.1093/mnras/stab1374",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2021-08",
"series_number": "2",
"volume": "505",
"issue": "2",
"pages": "2447-2467"
},
{
"id": "authors:pzcpm-wq594",
"collection": "authors",
"collection_id": "pzcpm-wq594",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200908-075612693",
"type": "article",
"title": "Revisiting the gas kinematics in SSA22 Lyman-\u03b1 Blob 1 with radiative transfer modelling in a multiphase, clumpy medium",
"author": [
{
"family_name": "Li",
"given_name": "Zhihui",
"orcid": "0000-0001-5113-7558",
"clpid": "Li-Zhihui"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Gronke",
"given_name": "Max",
"orcid": "0000-0003-2491-060X",
"clpid": "Gronke-Max"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
}
],
"abstract": "We present new observations of Lyman-\u03b1 (Ly\u03b1) Blob 1 (LAB1) in the SSA22 protocluster region (z = 3.09) using the Keck Cosmic Web Imager and Keck Multi-object Spectrometer for Infrared Exploration. We have created a narrow-band Ly\u03b1 image and identified several prominent features. By comparing the spatial distributions and intensities of Ly\u03b1 and H\u03b2, we find that recombination of photo-ionized H\u2009I gas followed by resonant scattering is sufficient to explain all the observed Ly\u03b1/H\u03b2 ratios. We further decode the spatially resolved Ly\u03b1 profiles using both moment maps and radiative transfer modelling. By fitting a set of multiphase, 'clumpy' models to the observed Ly\u03b1 profiles, we manage to reasonably constrain many parameters, namely the H\u2009I number density in the interclump medium (ICM), the cloud volume filling factor, the random velocity and outflow velocity of the clumps, the H\u2009I outflow velocity of the ICM, and the local systemic redshift. Our model has successfully reproduced the diverse Ly\u03b1 morphologies, and the main results are: (1) the observed Ly\u03b1 spectra require relatively few clumps per line of sight as they have significant fluxes at the line centre; (2) the velocity dispersion of the clumps yields a significant broadening of the spectra as observed; (3) the clump bulk outflow can also cause additional broadening if the H\u2009I in the ICM is optically thick; (4) and the H\u2009I in the ICM is responsible for the absorption feature close to the Ly\u03b1 line centre.",
"doi": "10.1093/mnras/staa3951",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2021-04",
"series_number": "2",
"volume": "502",
"issue": "2",
"pages": "2389-2408"
},
{
"id": "authors:bwww3-z8y74",
"collection": "authors",
"collection_id": "bwww3-z8y74",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200626-150116926",
"type": "article",
"title": "The Keck Baryonic Structure Survey: using foreground/background galaxy pairs to trace the structure and kinematics of circumgalactic neutral hydrogen at z \u223c 2",
"author": [
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Hummels",
"given_name": "Cameron B.",
"orcid": "0000-0002-3817-8133",
"clpid": "Hummels-Cameron-B"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-Gwen-C"
},
{
"family_name": "Dong",
"given_name": "Bili",
"clpid": "Dong-Bill"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-Ryan-F"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"orcid": "0000-0002-4710-4814",
"clpid": "Bogosavljevi\u0107-Milan"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-Dawn-K"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-Max"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-Naveen-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-Alice-E"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-Allison-L"
},
{
"family_name": "Theios",
"given_name": "Rachel L.",
"orcid": "0000-0002-4236-1037",
"clpid": "Theios-Rachel-L"
},
{
"family_name": "Faucher-Gigu\u00e8re",
"given_name": "Claude-Andr\u00e9",
"orcid": "0000-0002-4900-6628",
"clpid": "Faucher-Gigu\u00e8re-Claude-Andr\u00e9"
},
{
"family_name": "Hopkins",
"given_name": "Philip F.",
"orcid": "0000-0003-3729-1684",
"clpid": "Hopkins-P-F"
},
{
"family_name": "Kere\u0161",
"given_name": "Du\u0161an",
"orcid": "0000-0002-1666-7067",
"clpid": "Kere\u0161-Du\u0161an"
}
],
"abstract": "We present new measurements of the spatial distribution and kinematics of neutral hydrogen in the circumgalactic and intergalactic medium surrounding star-forming galaxies at z \u223c 2. Using the spectra of \u22433000 galaxies with redshifts \u3008z\u3009 = 2.3 \u00b1 0.4 from the Keck Baryonic Structure Survey, we assemble a sample of more than 200\u2009000 distinct foreground-background pairs with projected angular separations of 3\u2013500 arcsec and spectroscopic redshifts, with \u3008z_(fg)\u3009 = 2.23 and \u3008zbg\u3009 = 2.57 (foreground, background redshifts, respectively.) The ensemble of sightlines and foreground galaxies is used to construct a 2D map of the mean excess HI Ly\u03b1 optical depth relative to the intergalactic mean as a function of projected galactocentric distance (20 \u2272 D_(tran)/pkpc \u2272 4000) and line-of-sight velocity. We obtain accurate galaxy systemic redshifts, providing significant information on the line-of-sight kinematics of HI gas as a function of projected distance D_(tran). We compare the map with cosmological zoom-in simulation, finding qualitative agreement between them. A simple two-component (accretion, outflow) analytical model generally reproduces the observed line-of-sight kinematics and projected spatial distribution of HI. The best-fitting model suggests that galaxy-scale outflows with initial velocity v_(out) \u2243 600 km s\u207b\u00b9 dominate the kinematics of circumgalactic HI out to D_(tran) \u2243 50 kpc, while HI at D_(tran) \u2273 100 kpc is dominated by infall with characteristic v_(in) \u2272 circular velocity. Over the impact parameter range 80 \u2272 D_(tran)/pkpc \u2272 200, the HI line-of-sight velocity range reaches a minimum, with a corresponding flattening in the rest-frame Ly\u03b1 equivalent width. These observations can be naturally explained as the transition between outflow-dominated and accretion-dominated flows. Beyond D_(tran) \u2243 300\u2009pkpc (\u223c1\u2009cMpc), the line-of-sight kinematics are dominated by Hubble expansion.",
"doi": "10.1093/mnras/staa2808",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2020-12",
"series_number": "2",
"volume": "499",
"issue": "2",
"pages": "1721-1746"
},
{
"id": "authors:t11b8-q4p25",
"collection": "authors",
"collection_id": "t11b8-q4p25",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201021-160146951",
"type": "article",
"title": "The MOSDEF Survey: The First Direct Measurements of the Nebular Dust Attenuation Curve at High Redshift",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Kriek",
"given_name": "Mariska",
"orcid": "0000-0002-7613-9872",
"clpid": "Kriek-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shivaei",
"given_name": "Irene",
"orcid": "0000-0003-4702-7561",
"clpid": "Shivaei-Irene"
},
{
"family_name": "Sanders",
"given_name": "Ryan L.",
"orcid": "0000-0003-4792-9119",
"clpid": "Sanders-Ryan-L"
},
{
"family_name": "Mobasher",
"given_name": "Bahram",
"clpid": "Mobasher-B"
},
{
"family_name": "Coil",
"given_name": "Alison L.",
"orcid": "0000-0002-2583-5894",
"clpid": "Coil-A-L"
},
{
"family_name": "Siana",
"given_name": "Brian",
"orcid": "0000-0002-4935-9511",
"clpid": "Siana-Brian-D"
},
{
"family_name": "Freeman",
"given_name": "William R.",
"orcid": "0000-0003-3559-5270",
"clpid": "Freeman-W-R"
},
{
"family_name": "Azadi",
"given_name": "Mojegan",
"orcid": "0000-0001-6004-9728",
"clpid": "Azadi-M"
},
{
"family_name": "Fetherolf",
"given_name": "Tara",
"orcid": "0000-0002-3551-279X",
"clpid": "Fetherolf-T"
},
{
"family_name": "Leung",
"given_name": "Gene",
"orcid": "0000-0002-9393-6507",
"clpid": "Leung-Gene-C-K"
},
{
"family_name": "Price",
"given_name": "Sedona H.",
"orcid": "0000-0002-0108-4176",
"clpid": "Price-S-H"
},
{
"family_name": "Zick",
"given_name": "Tom",
"clpid": "Zick-T"
}
],
"abstract": "We use a sample of 532 star-forming galaxies at redshifts z \u2243 1.4\u20132.6 with deep rest-frame optical spectra from the MOSFIRE Deep Evolution Field (MOSDEF) survey to place the first constraints on the nebular attenuation curve at high redshift. Based on the first five low-order Balmer emission lines detected in the composite spectra of these galaxies (H\u03b1 through H\u03b5), we derive a nebular attenuation curve that is similar in shape to that of the Galactic extinction curve, suggesting that the dust covering fraction and absorption/scattering properties along the lines of sight to massive stars at high redshift are similar to those of the average Milky Way sight line. The curve derived here implies nebular reddening values that are, on average, systematically larger than those derived for the stellar continuum. In the context of stellar population synthesis models that include the effects of stellar multiplicity, the difference in reddening of the nebular lines and stellar continuum may imply molecular cloud crossing timescales that are a factor of \u2273 3x longer than those inferred for local molecular clouds, star formation rates that are constant or increasing with time such that newly formed and dustier OB associations always dominate the ionizing flux, and/or that the dust responsible for reddening the nebular emission may be associated with nonmolecular (i.e., ionized and neutral) phases of the interstellar medium. Our analysis points to a variety of investigations of the nebular attenuation curve that will be enabled with the next generation of ground- and space-based facilities.",
"doi": "10.3847/1538-4357/abb674",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2020-10-20",
"series_number": "2",
"volume": "902",
"issue": "2",
"pages": "Art. No. 123"
},
{
"id": "authors:j58d0-01206",
"collection": "authors",
"collection_id": "j58d0-01206",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191213-105036789",
"type": "article",
"title": "Predicting Ly\u03b1 Emission from Galaxies via Empirical Markers of Production and Escape in the KBSS",
"author": [
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
},
{
"family_name": "Theios",
"given_name": "Rachel L.",
"orcid": "0000-0002-4236-1037",
"clpid": "Theios-R-L"
}
],
"abstract": "Ly\u03b1 emission is widely used to detect and confirm high-redshift galaxies and characterize the evolution of the intergalactic medium (IGM). However, many galaxies do not display Ly\u03b1 emission in typical spectroscopic observations, and intrinsic Ly\u03b1 emitters represent a potentially biased set of high-redshift galaxies. In this work, we analyze a set of 703 galaxies at 2 \u227e z \u227e 3 with both Ly\u03b1 spectroscopy and measurements of other rest-frame ultraviolet and optical properties in order to develop an empirical model for Ly\u03b1 emission from galaxies and understand how the probability of Ly\u03b1 emission depends on other observables. We consider several empirical proxies for the efficiency of Ly\u03b1 photon production, as well as the subsequent escape of these photons through their local interstellar medium. We find that the equivalent width of metal-line absorption and the O3 ratio of rest-frame optical nebular lines are advantageous empirical proxies for Ly\u03b1 escape and production, respectively. We develop a new quantity, X_(LIS)^(O3), that combines these two properties into a single predictor of net Ly\u03b1 emission, which we find describes ~90% of the observed variance in Ly\u03b1 equivalent width when accounting for our observational uncertainties. We also construct conditional probability distributions demonstrating that galaxy selection based on measurements of galaxy properties yield samples of galaxies with widely varying probabilities of net Ly\u03b1 emission. The application of the empirical models and probability distributions described here may be used to infer the selection biases of current galaxy surveys and evaluate the significance of high-redshift Ly\u03b1 (non)detections in studies of reionization and the IGM.",
"doi": "10.3847/1538-4357/ab4993",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2019-12-10",
"series_number": "1",
"volume": "887",
"issue": "1",
"pages": "Art. No. 85"
},
{
"id": "authors:9ff3a-y8a36",
"collection": "authors",
"collection_id": "9ff3a-y8a36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191031-141639995",
"type": "article",
"title": "Column Density, Kinematics, and Thermal State of Metal-bearing Gas within the Virial Radius of z \u223c 2 Star-forming Galaxies in the Keck Baryonic Structure Survey",
"author": [
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Hummels",
"given_name": "Cameron B.",
"orcid": "0000-0002-3817-8133",
"clpid": "Hummels-C-B"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
}
],
"abstract": "We present results from the Keck Baryonic Structure Survey (KBSS) including the first detailed measurements of the column densities, kinematics, and internal energy of metal-bearing gas within the virial radius (35\u2013100 physical kpc) of eight ~L* galaxies at z ~ 2. From our full sample of 130 metal-bearing absorbers, we infer that halo gas is kinematically complex when viewed in singly, doubly, and triply ionized species. Broad O vi and C iv absorbers are detected at velocities similar to the lower-ionization gas but with a very different kinematic structure, indicating that the circumgalactic medium (CGM) is multiphase. There is a high covering fraction of metal-bearing gas within 100 kpc, including highly ionized gas such as O vi; however, observations of a single galaxy probed by a lensed background QSO suggest the size of metal-bearing clouds is small (<400 pc for all but the O vi-bearing gas). The mass in metals found within the halo is substantial, equivalent to \u227325% of the metal mass within the interstellar medium. The gas kinematics unambiguously show that 70% of galaxies with detected metal absorption have some unbound metal-enriched gas, suggesting galactic winds may commonly eject gas from halos at z ~ 2. When modeled assuming that ions with different ionization potentials can originate within a single gaseous structure, significant thermal broadening is detected in CGM absorbers that dominates the internal energy of the gas. Some 40% of the detected gas has temperatures in the range 10^(4.5-5.5) K where cooling times are short, suggesting the CGM is dynamic, with constant heating or cooling to produce this short-lived thermal phase.",
"doi": "10.3847/1538-4357/ab4255",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2019-11-01",
"series_number": "1",
"volume": "885",
"issue": "1",
"pages": "Art. No. 61"
},
{
"id": "authors:0ynak-kmy93",
"collection": "authors",
"collection_id": "0ynak-kmy93",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191004-072437663",
"type": "article",
"title": "Gas filaments of the cosmic web located around active galaxies in a protocluster",
"author": [
{
"family_name": "Umehata",
"given_name": "H.",
"clpid": "Umehata-Hideki"
},
{
"family_name": "Fumagalli",
"given_name": "M.",
"orcid": "0000-0001-6676-3842",
"clpid": "Fumagalli-M"
},
{
"family_name": "Smail",
"given_name": "I.",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Matsuda",
"given_name": "Y.",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Swinbank",
"given_name": "A. M.",
"clpid": "Swinbank-A-M"
},
{
"family_name": "Cantalupo",
"given_name": "S.",
"orcid": "0000-0001-5804-1428",
"clpid": "Cantalupo-S"
},
{
"family_name": "Sykes",
"given_name": "C.",
"clpid": "Sykes-C-M"
},
{
"family_name": "Ivison",
"given_name": "R. J.",
"orcid": "0000-0001-5118-1313",
"clpid": "Ivison-R-J"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Vernet",
"given_name": "J.",
"orcid": "0000-0002-8639-8560",
"clpid": "Vernet-Joel"
},
{
"family_name": "Yamada",
"given_name": "T.",
"clpid": "Yamada-Toru"
},
{
"family_name": "Tamura",
"given_name": "Y.",
"clpid": "Tamura-Yoichi"
},
{
"family_name": "Kubo",
"given_name": "M.",
"clpid": "Kubo-Mariko"
},
{
"family_name": "Nakanishi",
"given_name": "K.",
"orcid": "0000-0002-6939-0372",
"clpid": "Nakanishi-Kouichiro"
},
{
"family_name": "Kajisawa",
"given_name": "M.",
"orcid": "0000-0002-1732-6387",
"clpid": "Kajisawa-Masaru"
},
{
"family_name": "Hatsukade",
"given_name": "B.",
"clpid": "Hatsukade-Bunyo"
},
{
"family_name": "Kohno",
"given_name": "K.",
"orcid": "0000-0002-4052-2394",
"clpid": "Kohno-Kotaro"
}
],
"abstract": "Cosmological simulations predict that the Universe contains a network of intergalactic gas filaments, within which galaxies form and evolve. However, the faintness of any emission from these filaments has limited tests of this prediction. We report the detection of rest-frame ultraviolet Lyman-\u03b1 radiation from multiple filaments extending more than one megaparsec between galaxies within the SSA22 protocluster at a redshift of 3.1. Intense star formation and supermassive black-hole activity is occurring within the galaxies embedded in these structures, which are the likely sources of the elevated ionizing radiation powering the observed Lyman-\u03b1 emission. Our observations map the gas in filamentary structures of the type thought to fuel the growth of galaxies and black holes in massive protoclusters.",
"doi": "10.1126/science.aaw5949",
"issn": "0036-8075",
"publisher": "American Association for the Advancement of Science",
"publication": "Science",
"publication_date": "2019-10-04",
"series_number": "6461",
"volume": "366",
"issue": "6461",
"pages": "97-100"
},
{
"id": "authors:gt4jr-22n21",
"collection": "authors",
"collection_id": "gt4jr-22n21",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190912-081725307",
"type": "article",
"title": "Two sub-millimetre bright protoclusters bounding the epoch of peak star-formation activity",
"author": [
{
"family_name": "Lacaille",
"given_name": "Kevin M.",
"orcid": "0000-0001-9870-5663",
"clpid": "Lacaille-Kevin-M"
},
{
"family_name": "Chapman",
"given_name": "Scott C.",
"clpid": "Chapman-Scott-C"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Blain",
"given_name": "A. W.",
"orcid": "0000-0001-7489-5167",
"clpid": "Blain-Andrew-W"
},
{
"family_name": "Geach",
"given_name": "J.",
"orcid": "0000-0003-4964-4635",
"clpid": "Geach-James-E"
},
{
"family_name": "Golob",
"given_name": "A.",
"clpid": "Golob-Anneya"
},
{
"family_name": "Gurwell",
"given_name": "M.",
"orcid": "0000-0003-0685-3621",
"clpid": "Gurwell-Mark-A"
},
{
"family_name": "Ivison",
"given_name": "R. J.",
"orcid": "0000-0001-5118-1313",
"clpid": "Ivison-Rob-J"
},
{
"family_name": "Reddy",
"given_name": "N.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-Naveen-A"
},
{
"family_name": "Sawicki",
"given_name": "M.",
"orcid": "0000-0002-7712-7857",
"clpid": "Sawicki-Marcin"
}
],
"abstract": "We present James Clerk Maxwell Telescope Submillimetre Common-User Bolometer Array 2 (SCUBA-2) 850 and 450 \u03bcm observations (\u03c3_(850) \u223c 0.5 mJy, \u03c3_(450) \u223c 5 mJy) of the HS1549+19 and HS1700+64 survey fields containing two of the largest known galaxy overdensities at z = 2.85 and 2.30, respectively. We detect 56 sub-millimetre galaxies (SMGs) with SNR > 4 over \u223c50 arcmin^2 at 850 \u03bcm with flux densities of 3\u201317 mJy. The number counts indicate overdensities in the 3-arcmin diameter core region (\u223c1.5 Mpc at z = 2.5) of 6^(+4)_(\u22122)\u00d7 (HS1549) and 4^(+6)_(\u22122)\u00d7 (HS1700) compared to blank field surveys. Within these core regions, we spectroscopically confirm that approximately one-third of the SMGs lie at the protocluster redshifts for both HS1549 and HS1700. We use statistical identifications of other SMGs in the wider fields to constrain an additional four candidate protocluster members in each system. We combine multiwavelength estimates of the star-formation rates (SFRs) from Lyman-break dropout- and narrow-band-selected galaxies, and the SCUBA-2 SMGs, to estimate total SFRs of 12\u2009500 \u00b1 2800 M\u2299 yr^(\u22121) (4900 \u00b1 1200 M\u2299 yr^(\u22121)) in HS1549 (HS1700), and SFR densities (SFRDs) within the central 1.5-Mpc diameter of each protocluster to be 3000 \u00b1 900 M\u2299\u2009yr^(\u22121) Mpc^(\u22123) (1300 \u00b1 400 M\u2299 yr^(\u22121) Mpc^(\u22123)) in the HS1549 (HS1700) protocluster, \u223c10^4 \u00d7 larger than the global SFRDs found at their respective epochs, due to the concentration of star-forming galaxies in the small volume of the dense cluster cores. Our results suggest centrally concentrated starbursts within protoclusters may be a relatively common scenario for the build-up of mass in rich clusters assembling at z \u2273 2.",
"doi": "10.1093/mnras/stz1742",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2019-09",
"series_number": "2",
"volume": "488",
"issue": "2",
"pages": "1790-1812"
},
{
"id": "authors:2kcz7-hqx13",
"collection": "authors",
"collection_id": "2kcz7-hqx13",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190424-101356136",
"type": "article",
"title": "Multi-filament gas inflows fuelling young star-forming galaxies",
"author": [
{
"family_name": "Martin",
"given_name": "D. Christopher",
"orcid": "0000-0002-8650-1644",
"clpid": "Martin-D-Christopher"
},
{
"family_name": "O'Sullivan",
"given_name": "Donal",
"orcid": "0000-0002-4959-9179",
"clpid": "O'Sullivan-Donal"
},
{
"family_name": "Matuszewski",
"given_name": "Mateusz",
"clpid": "Matuszewski-M"
},
{
"family_name": "Hamden",
"given_name": "Erika T.",
"clpid": "Hamden-E-T"
},
{
"family_name": "Dekel",
"given_name": "Avishai",
"orcid": "0000-0003-4174-0374",
"clpid": "Dekel-Avishai"
},
{
"family_name": "Lapiner",
"given_name": "Sharon",
"clpid": "Lapiner-Sharon"
},
{
"family_name": "Morrissey",
"given_name": "Patrick",
"orcid": "0000-0001-8177-1023",
"clpid": "Morrissey-P"
},
{
"family_name": "Neill",
"given_name": "James D.",
"orcid": "0000-0002-0466-1119",
"clpid": "Neill-J-D"
},
{
"family_name": "Cantalupo",
"given_name": "Sebastiano",
"orcid": "0000-0001-5804-1428",
"clpid": "Cantalupo-S"
},
{
"family_name": "Prochaska",
"given_name": "Jason Xavier",
"orcid": "0000-0002-7738-6875",
"clpid": "Prochaska-J-X"
},
{
"family_name": "Steidel",
"given_name": "Charles",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Moore",
"given_name": "Anna",
"orcid": "0000-0002-2894-6936",
"clpid": "Moore-A-M"
},
{
"family_name": "Ceverino",
"given_name": "Daniel",
"orcid": "0000-0002-8680-248X",
"clpid": "Ceverino-D"
},
{
"family_name": "Primack",
"given_name": "Joel",
"orcid": "0000-0001-5091-5098",
"clpid": "Primack-J-R"
},
{
"family_name": "Rizzi",
"given_name": "Luca",
"orcid": "0000-0003-0882-2327",
"clpid": "Rizzi-L"
}
],
"abstract": "Theory suggests that there are two primary modes of accretion through which dark-matter halos acquire the gas to form and fuel galaxies: hot- and cold-flow accretion. In cold-flow accretion, gas streams along cosmic web filaments to the centre of the halo, allowing for the efficient delivery of star-forming fuel. Recently, two quasar-illuminated H\u2009I Lyman \u0251 (Ly\u03b1)-emitting objects were reported to have properties of cold, rotating structures. However, the spatial and spectral resolution available was insufficient to constrain the radial flows associated with connecting filaments. With the Keck Cosmic Web Imager (KCWI), we now have eight times the spatial resolution, permitting the detection of these inspiralling flows. To detect these inflows, we introduce a suite of models that incorporate zonal radial flows, demonstrate their performance on a numerical simulation that exhibits cold-flow accretion, and show that they are an excellent match to KCWI velocity maps of two Ly\u03b1 emitters observed around high-redshift quasars. These multi-filament inflow models kinematically isolate zones of radial inflow that correspond to extended filamentary emission. The derived gas flux and inflow path is sufficient to fuel the inferred central galaxy star-formation rate and angular momentum. Thus, our kinematic emission maps provide strong evidence that the inflow of gas from the cosmic web is building galaxies at the peak of star formation.",
"doi": "10.1038/s41550-019-0791-2",
"issn": "2397-3366",
"publisher": "Nature Publishing Group",
"publication": "Nature Astronomy",
"publication_date": "2019-09",
"series_number": "9",
"volume": "3",
"issue": "9",
"pages": "822-831"
},
{
"id": "authors:y6a34-1ey90",
"collection": "authors",
"collection_id": "y6a34-1ey90",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191025-154919609",
"type": "article",
"title": "Ly\u03b1 view around a z = 2.84 hyperluminous QSO at a node of the cosmic web",
"author": [
{
"family_name": "Kikuta",
"given_name": "Satoshi",
"clpid": "Kikuta-Satoshi"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Cen",
"given_name": "Renyue",
"clpid": "Cen-Renyue"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Yagi",
"given_name": "Masafumi",
"clpid": "Yagi-Masafumi"
},
{
"family_name": "Hayashino",
"given_name": "Tomoki",
"clpid": "Hahashino-Tomoki"
},
{
"family_name": "Imanishi",
"given_name": "Masatoshi",
"orcid": "0000-0001-6186-8792",
"clpid": "Imanishi-Masatoshi"
},
{
"family_name": "Komiyama",
"given_name": "Yutaka",
"clpid": "Komiyama-Yutaka"
},
{
"family_name": "Momose",
"given_name": "Rieko",
"clpid": "Momose-Rieko"
},
{
"family_name": "Saito",
"given_name": "Tomoki",
"clpid": "Saito-Tomoki"
}
],
"abstract": "We report on the results of deep and wide-field (1.1\u2009deg\u00b2) narrow-band observations with Subaru/Hyper Suprime-Cam (HSC) of a field around a hyperluminous QSO (HLQSO), HS1549+1549+1919, residing in a protocluster at z = 2.84, to map the large-scale structure of Ly\u03b1 emitters (LAEs). One HSC pointing enables us to detect 3490 LAEs and 76 extended Ly\u03b1 blobs (LABs), probing diverse environments from voids to protoclusters. The HLQSO is found to be near the center of the protocluster, which corresponds to the intersection of \u223c100 comoving Mpc-scale structures of LAEs. LABs are basically distributed along the large-scale structure, with larger ones particularly clustering around the HLQSO, confirming a previously noted tendency of LABs to prefer denser environments. Moreover, the shapes of LABs near the HLQSO appear to be aligned with the large-scale structure. Finally, a deep Ly\u03b1 image reveals a diffuse Ly\u03b1 nebula along a filamentary structure with no luminous UV/sub-mm counterpart. We suggest that the diffuse nebula is due to a cold filament with high clumping factor illuminated by the QSO, with the required high clumpiness provided by unresolved residing halos of mass \u226410\u2079\u207b\u00b9\u2070 M_\u2299\u2060.",
"doi": "10.1093/pasj/psz055",
"issn": "0004-6264",
"publisher": "Astronomical Society of Japan",
"publication": "Publications of the Astronomical Society of Japan",
"publication_date": "2019-06",
"series_number": "3",
"volume": "71",
"issue": "3",
"pages": "Art. No. L2"
},
{
"id": "authors:fdnhb-wtz64",
"collection": "authors",
"collection_id": "fdnhb-wtz64",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190523-111840539",
"type": "article",
"title": "SCUBA-2 web survey: I. Observations of CO(3\u20132) in hyper-luminous QSO fields",
"author": [
{
"family_name": "Hill",
"given_name": "Ryley",
"clpid": "Hill-Ryley"
},
{
"family_name": "Chapman",
"given_name": "Scott C.",
"clpid": "Chapman-Scott-C"
},
{
"family_name": "Scott",
"given_name": "Douglas",
"orcid": "0000-0002-6878-9840",
"clpid": "Scott-Douglas"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Krips",
"given_name": "Melanie",
"clpid": "Krips-Melanie"
},
{
"family_name": "Babul",
"given_name": "Arif",
"orcid": "0000-0003-1746-9529",
"clpid": "Babul-Arif"
},
{
"family_name": "Berg",
"given_name": "Trystyn",
"orcid": "0000-0002-2606-5078",
"clpid": "Berg-Trystyn"
},
{
"family_name": "Bertoldi",
"given_name": "Frank",
"orcid": "0000-0002-1707-1775",
"clpid": "Bertoldi-Frank"
},
{
"family_name": "Gao",
"given_name": "Yu",
"orcid": "0000-0003-0007-2197",
"clpid": "Gao-Yu"
},
{
"family_name": "Lacaille",
"given_name": "Kevin",
"orcid": "0000-0001-9870-5663",
"clpid": "Lacaille-Kevin-M"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Ross",
"given_name": "Colin",
"clpid": "Ross-Colin"
},
{
"family_name": "Rudie",
"given_name": "Gwen",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-Gwen-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-Ryan-F"
}
],
"abstract": "A primary goal of the Submillimetre Common User Bolometer Array-2 web survey is to perform tomography of the early intergalactic medium by studying systems containing some of the brightest quasi-stellar objects (QSOs; 2.5 < z < 3.0) and nearby submillimetre galaxies (SMGs). As a first step, this paper aims to characterize the galaxies that host the QSOs. To achieve this, a sample of 13 hyper-luminous (\u2060L_(AGN) > 10^(14) L\u2299) QSOs with previous submillimetre continuum detections were followed up with CO(3\u20132) observations using the NOrthern Extended Millimeter Array interferometer. All but two of the QSOs are detected in CO(3\u20132); for one non-detection, our observations show a tentative 2\u03c3 line at the expected position and redshift, and for the other non-detection we find only continuum flux density an order of magnitude brighter than the other sources. In three of the fields, a companion potentially suitable for tomography is detected in CO line emission within 25\u2009arcsec of the QSO. We derive gas masses, dynamical masses, and far-infrared luminosities, and show that the QSOs in our sample have similar properties compared to less luminous QSOs and SMGs in the literature, despite the fact that their black hole masses (which are proportional to L_(AGN)) are 1\u20132 orders of magnitude larger. We discuss two interpretations of these observations: this is due to selection effects, such as preferential face-on viewing angles and picking out objects in the tail ends of the scatter in host-galaxy mass and black hole mass relationships; or the black hole masses have been overestimated because the accretion rates are super-Eddington.",
"doi": "10.1093/mnras/stz429",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2019-05",
"series_number": "1",
"volume": "485",
"issue": "1",
"pages": "753-769"
},
{
"id": "authors:stdpm-0na72",
"collection": "authors",
"collection_id": "stdpm-0na72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181129-135233204",
"type": "article",
"title": "Dust Attenuation, Star Formation, and Metallicity in z ~ 2-3 Galaxies \n from KBSS-MOSFIRE",
"author": [
{
"family_name": "Theios",
"given_name": "Rachel L.",
"orcid": "0000-0002-4236-1037",
"clpid": "Theios-R-L"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
}
],
"abstract": "We present a detailed analysis of 317 2.0 \u2264 z \u2264 2.7 star-forming galaxies from the Keck Baryonic Structure Survey. Using complementary spectroscopic observations with Keck/LRIS and Keck/MOSFIRE, as well as spectral energy distribution (SED) fits to broadband photometry, we examine the joint rest-UV and rest-optical properties of the same galaxies, including stellar and nebular dust attenuation, metallicity, and star formation rate (SFR). The inferred parameters of the stellar population (reddening, age, SFR, and stellar mass) are strongly dependent on the details of the assumed stellar population model and the shape of the attenuation curve. Nebular reddening is generally larger than continuum reddening, but with large scatter. Compared to local galaxies, high-redshift galaxies have lower gas-phase metallicities (and/or higher nebular excitation) at fixed nebular reddening, and higher nebular reddening at fixed stellar mass, consistent with gas fractions that increase with redshift. We find that continuum reddening is correlated with 12 + log(O/H)_(O3N2) at 3.0\u03c3 significance, whereas nebular reddening is correlated with only 1.1\u03c3 significance. This may reflect the dependence of both continuum reddening and O3N2 on the shape of the ionizing radiation field produced by the massive stars. Finally, we show that H\u03b1-based and SED-based estimates of SFR exhibit significant scatter relative to one another, and on average agree only for particular combinations of spectral synthesis models and attenuation curves. We find that the SMC extinction curve predicts consistent SFRs if we assume the subsolar (0.14 Z\u2299) binary star models that are favored for high-redshift galaxies.",
"doi": "10.3847/1538-4357/aaf386",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2019-01-20",
"series_number": "1",
"volume": "871",
"issue": "1",
"pages": "Art. No. 128"
},
{
"id": "authors:t59zs-kmb59",
"collection": "authors",
"collection_id": "t59zs-kmb59",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181129-135236660",
"type": "article",
"title": "The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at z \u223c 3",
"author": [
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
}
],
"abstract": "We present results of a deep spectroscopic survey quantifying the statistics of the escape of ionizing radiation from star-forming galaxies at z ~ 3. We measure the ratio of ionizing to non-ionizing UV flux density \u3008f_(900)/f_(1500) \u3009_(obs), where f_(900) is the mean flux density evaluated over the range [880, 910] \u00c5. We quantify the emergent ratio of ionizing to non-ionizing UV flux density by analyzing high signal-to-noise ratio composite spectra formed from subsamples with common observed properties and numbers sufficient to reduce the statistical uncertainty in the modeled IGM+CGM correction to obtain precise values of \u3008f_(900)/f_(1500) \u3009_(out), including a full-sample average \u3008f_(900)/f_(1500) \u3009_(out) = 0.057 \u00b1 0.006. We show that \u3008f_(900)/f_(1500) \u3009_(out) increases monotonically with W_ \u03bb(Ly\u03b1), inducing an inverse correlation with UV luminosity as a by-product. We fit the composite spectra using stellar spectral synthesis together with models of the ISM in which a fraction f c of the stellar continuum is covered by gas with column density N_(H1). We show that the composite spectra simultaneously constrain the intrinsic properties of the stars (L_(900)/L_(1500))_(int) along with f_c , N_(H1), E(B - V), and f_(esc,abs), the absolute escape fraction of ionizing photons. We find a sample-averaged f-(esc,abs) = 0.09 \u00b1 0.01, with subsamples falling along a linear relation \u3008f_(esc,abs) \u3009 \u2243\n0.75[W_ \u03bb(Ly\u03b1)/110 \u00c5]. Using the far-UV luminosity function, the distribution function n(W(Ly\u03b1)), and the relationship between W_ \u03bb(Ly\u03b1) and f_(900)/f_(1500) \u3009_(out), we estimate the total ionizing emissivity of z ~ 3 star-forming galaxies with M_(uv) \u2264 \u221219.5, which exceeds the contribution of quasi-stellar objects by a factor of ~3, and accounts for ~50% of the total \u03f5_(LyC) at z ~ 3 estimated using indirect methods.",
"doi": "10.3847/1538-4357/aaed28",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2018-12-20",
"series_number": "2",
"volume": "869",
"issue": "2",
"pages": "Art. No. 123"
},
{
"id": "authors:6xg2f-w4a38",
"collection": "authors",
"collection_id": "6xg2f-w4a38",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181129-110052473",
"type": "article",
"title": "Measuring the Physical Conditions in High-redshift Star-forming Galaxies: Insights from KBSS-MOSFIRE",
"author": [
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "We use photoionization models that are designed to reconcile the joint rest-UV-optical spectra of high-z star-forming galaxies to self-consistently infer the gas chemistry and nebular ionization and excitation conditions for ~150 galaxies from the Keck Baryonic Structure Survey (KBSS), using only observations of their rest-optical nebular spectra. We find that the majority of z ~ 2\u20133 KBSS galaxies are moderately O-rich, with an interquartile range in 12 + log(O/H) = 8.29\u20138.56, and have significantly sub-solar Fe enrichment, with an interquartile range of [Fe/H] = [\u22120.79, \u22120.53], which contributes additional evidence in favor of super-solar O/Fe in high-z galaxies. The model-inferred ionization parameters and N/O are strongly correlated with common strong-line indices (such as O32 and N2O2), with the latter exhibiting similar behavior to local extragalactic H ii regions. In contrast, diagnostics commonly used for measuring gas-phase O/H (such as N2 and O3N2) show relatively large scatter with the overall amount of oxygen present in the gas and behave differently than observed at z ~ 0. We provide a new calibration for using R23 to measure O/H in typical high-z galaxies, although it is most useful for relatively O-rich galaxies; combining O32 and R23 does not yield a more effective calibration. Finally, we consider the implications for the intrinsic correlations between physical conditions across the galaxy sample and find that N/O varies with O/H in high-z galaxies in a manner that is almost identical to local H ii regions. However, we do not find a strong anti-correlation between ionization parameter and metallicity (O/H or Fe/H) in high-z galaxies, which is one of the principal bases for using strong-line ratios to infer oxygen abundance.",
"doi": "10.3847/1538-4357/aae1a5",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2018-12-01",
"series_number": "2",
"volume": "868",
"issue": "2",
"pages": "Art. No. 117"
},
{
"id": "authors:kk3q3-vy571",
"collection": "authors",
"collection_id": "kk3q3-vy571",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181023-082855040",
"type": "article",
"title": "Imaging Spectroscopy of Ionized Gaseous Nebulae around Optically Faint AGNs at Redshift z \u223c 2",
"author": [
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
}
],
"abstract": "We present Keck/OSIRIS laser guide-star assisted adaptive optics (LGSAO) integral-field spectroscopy of [O III] \u03bb5007 nebular emission from 12 galaxies hosting optically faint (R = 20\u201325; \u03bd L_\u03bd ~ 10^(44) \u2013 10^(46) erg s^(\u22121)) active galactic nuclei (AGNs) at redshift z ~ 2\u20133. In combination with deep Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) rest-frame optical imaging, Keck/MOSFIRE rest-optical spectroscopy, and Keck/KCWI rest-UV integral-field spectroscopy, we demonstrate that both the continuum and emission-line structures of these sources exhibit a wide range of morphologies, from compact, isolated point sources to double-AGN merging systems with extensive ~50 kpc tidal tails. One of the 12 galaxies previously known to exhibit a proximate damped Ly\u03b1 system coincident in redshift with the galaxy shows evidence for both an extended [O III] narrow-line emission region and spatially offset Ly\u03b1 emission (with morphologically distinct blueshifted and redshifted components) indicative of large-scale gas flows photoionized by the central AGN. We do not find widespread evidence of star formation in the host galaxies surrounding these AGNs; the [O III] velocity dispersions tend to be high (\u03c3 = 100\u2013500 km s^(-1)), the continuum morphologies are much more compact than a mass-matched star-forming comparison sample, and the diagnostic nebular emission-line ratios are dominated by an AGN-like ionizing spectrum. The sample is most consistent with a population of AGNs that radiate at approximately their Eddington limit and photoionize extended [O III] nebulae whose characteristic sizes scale approximately as the square root of the AGN luminosity.",
"doi": "10.3847/1538-4357/aae156",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2018-10-20",
"series_number": "2",
"volume": "866",
"issue": "2",
"pages": "Art. No. 119"
},
{
"id": "authors:egwej-8z636",
"collection": "authors",
"collection_id": "egwej-8z636",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180808-145514148",
"type": "article",
"title": "The Kinematics of Extended Ly\u03b1 Emission in a Low-mass, Low-metallicity Galaxy at z = 2.3",
"author": [
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chen",
"given_name": "Yuguang",
"orcid": "0000-0003-4520-5395",
"clpid": "Chen-Yuguang"
}
],
"abstract": "Ly\u03b1 photons are resonantly scattered by neutral hydrogen, and may therefore trace both the spatial extent and the kinematics of the gas surrounding galaxies. We present new observations of the extended Ly\u03b1 halo of Q2343-BX418, a low-mass (M\u22c6 = 5 x 10^8 M\u2299), low-metallicity (Z \u2248 0.25 Z\u2299) star-forming galaxy at z = 2.3. Using the Keck Cosmic Web Imager (KCWI), the blue-sensitive optical integral field spectrograph recently installed on the Keck II telescope, we detect Ly\u03b1 in emission to a radius of 23 kpc, and measure an exponential scale length of 6 kpc in the outer region of the extended halo. We study the double-peaked spectroscopic Ly\u03b1 profile in individual spectral pixels (\"spaxels\") over a ~25 \u00d7 30 kpc region, finding significant variations in the peak ratio and peak separation. The profile is dominated by the red peak in the central regions, while in the outskirts of the extended halo the red and blue peak strengths are roughly equal; these observations are consistent with a model in which the peak ratio is largely determined by the radial component of the outflow velocity. We find a gradient of 300 km s^(-1) in the Ly\u03b1 peak separation across the extended halo, indicating variations in the column density, covering fraction, or velocity range of the gas. These new observations emphasize the need for realistic, spatially resolved models of Ly\u03b1 radiative transfer in the halos of galaxies.",
"doi": "10.3847/2041-8213/aacff6",
"issn": "2041-8213",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2018-07-20",
"series_number": "1",
"volume": "862",
"issue": "1",
"pages": "Art. No. L10"
},
{
"id": "authors:vak9j-gtx16",
"collection": "authors",
"collection_id": "vak9j-gtx16",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180801-164036045",
"type": "article",
"title": "HDUV: The Hubble Deep UV Legacy Survey",
"author": [
{
"family_name": "Oesch",
"given_name": "P. A.",
"orcid": "0000-0001-5851-6649",
"clpid": "Oesch-P-A"
},
{
"family_name": "Montes",
"given_name": "M.",
"orcid": "0000-0001-7847-0393",
"clpid": "Montes-M"
},
{
"family_name": "Reddy",
"given_name": "N.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Bouwens",
"given_name": "R. J.",
"orcid": "0000-0002-4989-2471",
"clpid": "Bouwens-R-J"
},
{
"family_name": "Illingworth",
"given_name": "G. D.",
"orcid": "0000-0002-8096-2837",
"clpid": "Illingworth-G-D"
},
{
"family_name": "Magee",
"given_name": "D.",
"clpid": "Magee-D-K"
},
{
"family_name": "Atek",
"given_name": "H.",
"orcid": "0000-0002-7570-0824",
"clpid": "Atek-H"
},
{
"family_name": "Carollo",
"given_name": "C. M.",
"orcid": "0000-0003-1624-7609",
"clpid": "Carollo-C-Marcella"
},
{
"family_name": "Cibinel",
"given_name": "A.",
"orcid": "0000-0003-4578-514X",
"clpid": "Cibinel-A"
},
{
"family_name": "Franx",
"given_name": "M.",
"orcid": "0000-0002-8871-3026",
"clpid": "Franx-M"
},
{
"family_name": "Holden",
"given_name": "B.",
"orcid": "0000-0002-6153-3076",
"clpid": "Holden-B-P"
},
{
"family_name": "Labb\u00e9",
"given_name": "I.",
"orcid": "0000-0002-2057-5376",
"clpid": "Labb\u00e9-I"
},
{
"family_name": "Nelson",
"given_name": "E. J.",
"orcid": "0000-0002-7524-374X",
"clpid": "Nelson-E-J"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "van Dokkum",
"given_name": "P. G.",
"orcid": "0000-0002-8282-9888",
"clpid": "van-Dokkum-P-G"
},
{
"family_name": "Morselli",
"given_name": "L.",
"clpid": "Morselli-L"
},
{
"family_name": "Naidu",
"given_name": "R. P.",
"orcid": "0000-0003-3997-5705",
"clpid": "Naidu-R-P"
},
{
"family_name": "Wilkins",
"given_name": "S.",
"clpid": "Wilkins-S"
}
],
"abstract": "We present the Hubble Deep UV Legacy Survey (HDUV), a 132-orbit imaging program with the WFC3/UVIS camera on board the Hubble Space Telescope (HST). The HDUV extends and builds on the few previous UV imaging surveys in the two GOODS/CANDELS-Deep fields to provide deep images over a total area of ~100 arcmin2 in the two filters F275W and F336W. Our release also includes all the F275W imaging data taken by the CANDELS survey, which were aligned using a novel approach and combined with the HDUV survey data. By reaching depths of 27.5\u201328.0 mag (5\u03c3 in 0farcs4 apertures), these are the deepest high-resolution UV data over such a large area taken to date. Such unique UV imaging enables a wide range of science by the community. A few of the main goals of the HDUV survey are as follows: (1) to provide a complete sample of faint star-forming galaxies at z ~ 1\u20133; (2) to constrain the ionizing photon escape fraction from galaxies at z ~ 2\u20133; and (3) to track the build-up of bulges and the disappearance of clumpy disk galaxies through reliable internal stellar population properties at sub-kiloparsec resolution out to z ~ 3. The addition of the HDUV data further enhances the legacy value of the two GOODS/CANDELS-Deep fields, which now include deep 11-band HST imaging, as well as very deep ancillary data from X-ray to radio, enabling unique multi-wavelength studies. Here, we provide an overview of the survey design, describe the data reduction, and highlight a few basic analyses of the images that are available to the community as high-level science products, via the Mikulski Archive for Space Telescopes.",
"doi": "10.3847/1538-4365/aacb30",
"issn": "0067-0049",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Supplement Series",
"publication_date": "2018-07",
"series_number": "1",
"volume": "237",
"issue": "1",
"pages": "Art. No. 12"
},
{
"id": "authors:2q37d-d1838",
"collection": "authors",
"collection_id": "2q37d-d1838",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180613-094038182",
"type": "article",
"title": "The Redshift Evolution of Rest-UV Spectroscopic Properties in Lyman-break Galaxies at z ~ 2\u20134",
"author": [
{
"family_name": "Du",
"given_name": "Xinnan",
"clpid": "Du-Xinnan"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Jones",
"given_name": "Tucker",
"orcid": "0000-0001-5860-3419",
"clpid": "Jones-T"
},
{
"family_name": "Stark",
"given_name": "Daniel P.",
"clpid": "Stark-D-P"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Ellis",
"given_name": "Richard S.",
"orcid": "0000-0001-7782-7071",
"clpid": "Ellis-R-S"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "We present the first comprehensive evolutionary analysis of the rest-frame UV spectroscopic properties of star-forming galaxies at z ~ 2\u20134. We match samples at different redshifts in UV luminosity and stellar mass, and perform systematic measurements of spectral features and stellar population modeling. By creating composite spectra grouped according to Ly\u03b1 equivalent width (EW) and various galaxy properties, we study the evolutionary trends among Ly\u03b1, low- and high-ionization interstellar (LIS and HIS) absorption features, and integrated galaxy properties. We also examine the redshift evolution of Ly\u03b1 and LIS absorption kinematics, and fine-structure emission EWs. The connections among the strengths of Ly\u03b1, LIS lines, and dust extinction are redshift independent, as is the decoupling of the Ly\u03b1 and HIS line strengths, and the bulk outflow kinematics as traced by the LIS lines. Stronger Ly\u03b1 emission is observed at higher redshift at fixed UV luminosity, stellar mass, SFR, and age. Much of this variation in the average Ly\u03b1 strength with redshift, and the variation in Ly\u03b1 strength at fixed redshift, can be explained in terms of variations in the neutral gas covering fraction and/or dust content in the ISM and CGM. However, based on the connection between Ly\u03b1 and C iii] emission strengths, we additionally find evidence for variations in the intrinsic production rate of Ly\u03b1 photons at the highest Ly\u03b1 EWs. The challenge now is to understand the observed evolution of the neutral gas covering fraction and dust extinction within a coherent model for galaxy formation, and make robust predictions for the escape of ionizing radiation at z > 6.",
"doi": "10.3847/1538-4357/aabfcf",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2018-06-10",
"series_number": "1",
"volume": "860",
"issue": "1",
"pages": "Art. No. 75"
},
{
"id": "authors:arbz6-cbp56",
"collection": "authors",
"collection_id": "arbz6-cbp56",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180509-152638878",
"type": "article",
"title": "Observational constraints on the physical nature of submillimetre source multiplicity: chance projections are common",
"author": [
{
"family_name": "Hayward",
"given_name": "Christopher C.",
"orcid": "0000-0003-4073-3236",
"clpid": "Hayward-C-C"
},
{
"family_name": "Chapman",
"given_name": "Scott C.",
"clpid": "Chapman-S-C"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Golob",
"given_name": "Anneya",
"clpid": "Golob-A"
},
{
"family_name": "Casey",
"given_name": "Caitlin M.",
"orcid": "0000-0002-0930-6466",
"clpid": "Casey-C-M"
},
{
"family_name": "Smith",
"given_name": "Daniel J. B.",
"clpid": "Smith-D-J-B"
},
{
"family_name": "Zitrin",
"given_name": "Adi",
"orcid": "0000-0002-0350-4488",
"clpid": "Zitrin-Adi"
},
{
"family_name": "Blain",
"given_name": "Andrew W.",
"orcid": "0000-0001-7489-5167",
"clpid": "Blain-A-W"
},
{
"family_name": "Bremer",
"given_name": "Malcolm N.",
"clpid": "Bremer-M-N"
},
{
"family_name": "Chen",
"given_name": "Chian-Chou",
"orcid": "0000-0002-3805-0789",
"clpid": "Chen-Chian-Chou"
},
{
"family_name": "Coppin",
"given_name": "Kristen E. K.",
"clpid": "Coppin-K-E-K"
},
{
"family_name": "Farrah",
"given_name": "Duncan",
"orcid": "0000-0003-1748-2010",
"clpid": "Farrah-D"
},
{
"family_name": "Ibar",
"given_name": "Eduardo",
"clpid": "Ibar-E"
},
{
"family_name": "Micha\u0142owski",
"given_name": "Micha\u0142 J.",
"orcid": "0000-0001-9033-4140",
"clpid": "Micha\u0142owski-M-J"
},
{
"family_name": "Sawicki",
"given_name": "Marcin",
"orcid": "0000-0002-7712-7857",
"clpid": "Sawicki-M"
},
{
"family_name": "Scott",
"given_name": "Douglas",
"orcid": "0000-0002-6878-9840",
"clpid": "Scott-D"
},
{
"family_name": "van der Werf",
"given_name": "Paul",
"orcid": "0000-0001-5434-5942",
"clpid": "van-der-Werf-P-P"
},
{
"family_name": "Fazio",
"given_name": "Giovanni G.",
"orcid": "0000-0002-0670-0708",
"clpid": "Fazio-G-G"
},
{
"family_name": "Geach",
"given_name": "James E.",
"orcid": "0000-0003-4964-4635",
"clpid": "Geach-J-E"
},
{
"family_name": "Gurwell",
"given_name": "Mark",
"orcid": "0000-0003-0685-3621",
"clpid": "Gurwell-M-A"
},
{
"family_name": "Petitpas",
"given_name": "Glen",
"clpid": "Petitpas-G-R"
},
{
"family_name": "Wilner",
"given_name": "David J.",
"orcid": "0000-0003-1526-7587",
"clpid": "Wilner-D-J"
}
],
"abstract": "Interferometric observations have demonstrated that a significant fraction of single-dish submillimetre (submm) sources are blends of multiple submm galaxies (SMGs), but the nature of this multiplicity, i.e. whether the galaxies are physically associated or chance projections, has not been determined. We performed spectroscopy of 11 SMGs in six multicomponent submm sources, obtaining spectroscopic redshifts for nine of them. For an additional two component SMGs, we detected continuum emission but no obvious features. We supplement our observed sources with four single-dish submm sources from the literature. This sample allows us to statistically constrain the physical nature of single-dish submm source multiplicity for the first time. In three (3/7, or 43^(+39__(\u221233) per cent at 95 percent confidence) of the single-dish sources for which the nature of the blending is unambiguous, the components for which spectroscopic redshifts are available are physically associated, whereas 4/7 (57^(+33)_(\u221239) per cent) have at least one unassociated component. When components whose spectra exhibit continuum but no features and for which the photometric redshift is significantly different from the spectroscopic redshift of the other component are also considered, 6/9 (67^(+26)_(\u221237) per cent) of the single-dish sources are comprised of at least one unassociated component SMG. The nature of the multiplicity of one single-dish source is ambiguous. We conclude that physically associated systems and chance projections both contribute to the multicomponent single-dish submm source population. This result contradicts the conventional wisdom that bright submm sources are solely a result of merger-induced starbursts, as blending of unassociated galaxies is also important.",
"doi": "10.1093/mnras/sty304",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2018-05-11",
"series_number": "2",
"volume": "476",
"issue": "2",
"pages": "2278-2287"
},
{
"id": "authors:9ag5t-p7362",
"collection": "authors",
"collection_id": "9ag5t-p7362",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180312-102710851",
"type": "article",
"title": "One Percent Determination of the Primordial Deuterium Abundance",
"author": [
{
"family_name": "Cooke",
"given_name": "Ryan J.",
"orcid": "0000-0001-7653-5827",
"clpid": "Cooke-R-J"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We report a reanalysis of a near-pristine absorption system, located at a redshift z_(abs) = 2.52564 toward the quasar Q1243+307, based on the combination of archival and new data obtained with the HIRES echelle spectrograph on the Keck telescope. This absorption system, which has an oxygen abundance [O/H] = \u22122.769 \u00b1 0.028 ( 1/600 of the solar abundance), is among the lowest metallicity systems currently known where a precise measurement of the deuterium abundance is afforded. Our detailed analysis of this system concludes, on the basis of eight D I absorption lines, that the deuterium abundance of this gas cloud is log_(10)(D/H) = -4.622 \u00b1 0.015, which is in very good agreement with the results previously reported by Kirkman et al., but with an improvement on the precision of this single measurement by a factor of ~3.5. Combining this new estimate with our previous sample of six high precision and homogeneously analyzed D/H measurements, we deduce that the primordial deuterium abundance is log_(10)(D/H)_P = -4.5974 \u00b1 0.0052 or, expressed as a linear quantity, 10^5(D/H)_P = 2.527 \u00b1 0.030; this value corresponds to a one percent determination of the primordial deuterium abundance. Combining our result with a big bang nucleosynthesis (BBN) calculation that uses the latest nuclear physics input, we find that the baryon density derived from BBN agrees to within 2\u03c3 of the latest results from the Planck cosmic microwave background data.",
"doi": "10.3847/1538-4357/aaab53",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2018-03-10",
"series_number": "2",
"volume": "855",
"issue": "2",
"pages": "Art. No. 102"
},
{
"id": "authors:0zej3-aam34",
"collection": "authors",
"collection_id": "0zej3-aam34",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180201-082359298",
"type": "article",
"title": "The HDUV Survey: A Revised Assessment of the Relationship between UV Slope and Dust Attenuation for High-redshift Galaxies",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Oesch",
"given_name": "Pascal A.",
"orcid": "0000-0001-5851-6649",
"clpid": "Oesch-P-A"
},
{
"family_name": "Bouwens",
"given_name": "Rychard J.",
"orcid": "0000-0002-4989-2471",
"clpid": "Bouwens-R-J"
},
{
"family_name": "Montes",
"given_name": "Mireia",
"orcid": "0000-0001-7847-0393",
"clpid": "Montes-M"
},
{
"family_name": "Illingworth",
"given_name": "Garth D.",
"orcid": "0000-0002-6668-2011",
"clpid": "Illingworth-G-D"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "van Dokkum",
"given_name": "Pieter G.",
"orcid": "0000-0002-8282-9888",
"clpid": "van-Dokkum-P-G"
},
{
"family_name": "Atek",
"given_name": "Hakim",
"orcid": "0000-0002-7570-0824",
"clpid": "Atek-H"
},
{
"family_name": "Carollo",
"given_name": "Marcella C.",
"orcid": "0000-0003-1624-7609",
"clpid": "Carollo-C-Marcella"
},
{
"family_name": "Cibinel",
"given_name": "Anna",
"orcid": "0000-0003-4578-514X",
"clpid": "Cibinel-A"
},
{
"family_name": "Holden",
"given_name": "Brad",
"orcid": "0000-0002-6153-3076",
"clpid": "Holden-B"
},
{
"family_name": "Labb\u00e9",
"given_name": "Ivo",
"orcid": "0000-0002-2057-5376",
"clpid": "Labb\u00e9-I"
},
{
"family_name": "Magee",
"given_name": "Dan",
"clpid": "Magee-D-K"
},
{
"family_name": "Morselli",
"given_name": "Laura",
"clpid": "Morselli-"
},
{
"family_name": "Nelson",
"given_name": "Erica J.",
"orcid": "0000-0002-7524-374X",
"clpid": "Nelson-E-J"
},
{
"family_name": "Wilkins",
"given_name": "Steve",
"clpid": "Wilkins-S"
}
],
"abstract": "We use a newly assembled sample of 3545 star-forming galaxies with secure spectroscopic, grism, and photometric redshifts at z = 1.5\u20132.5 to constrain the relationship between UV slope (\u03b2) and dust attenuation (L_(IR)/L_(UV) \u2261 IRX). Our sample significantly extends the range of L_(UV) and \u03b2 probed in previous UV-selected samples, including those as faint as M_(1600) = \u221217.4 (\u22430.05L_(UV)^*) and \u22122.6 \u227e \u03b2 \u227e 0.0. IRX is measured using stacks of deep Herschel data, and the results are compared with predictions of the IRX\u2212\u03b2 relation for different assumptions of the stellar population model and obscuration curve. We find that z = 1.5\u20132.5 galaxies have an IRX\u2212\u03b2 relation that is consistent with the predictions for an SMC curve if we invoke subsolar-metallicity models currently favored for high-redshift galaxies, while the commonly assumed starburst curve overpredicts the IRX at a given \u03b2 by a factor of \u22733. IRX is roughly constant with L_(UV) for L_(UV) \u2273 3 \u00d7 10^9 L_\u2299. Thus, the commonly observed trend of fainter galaxies having bluer \u03b2 may simply reflect bluer intrinsic slopes for such galaxies, rather than lower obscurations. The IRX\u2212\u03b2 relation for young/low-mass galaxies at z \u2273 2 implies a dust curve that is steeper than the SMC. The lower attenuations and higher ionizing photon output for low-metallicity stellar populations point to Lyman continuum production efficiencies, \u03be_(ion), that may be elevated by a factor of \u22482 relative to the canonical value for L^* galaxies, aiding in their ability to keep the universe ionized at z ~ 2.",
"doi": "10.3847/1538-4357/aaa3e7",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2018-01-20",
"series_number": "1",
"volume": "853",
"issue": "1",
"pages": "Art. No. 56"
},
{
"id": "authors:k90je-bxd26",
"collection": "authors",
"collection_id": "k90je-bxd26",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180118-133854987",
"type": "article",
"title": "Understanding Large-scale Structure in the SSA22 Protocluster Region Using Cosmological Simulations",
"author": [
{
"family_name": "Topping",
"given_name": "Michael W.",
"clpid": "Topping-M-W"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Naoz",
"given_name": "Smadar",
"orcid": "0000-0002-9802-9279",
"clpid": "Naoz-S"
},
{
"family_name": "Primack",
"given_name": "Joel R.",
"orcid": "0000-0001-5091-5098",
"clpid": "Primack-J-R"
}
],
"abstract": "We investigate the nature and evolution of large-scale structure within the SSA22 protocluster region at z = 3.09 using cosmological simulations. A redshift histogram constructed from current spectroscopic observations of the SSA22 protocluster reveals two separate peaks at z = 3.065 (blue) and z = 3.095 (red). Based on these data, we report updated overdensity and mass calculations for the SSA22 protocluster. We find \u03b4_(b.gal) = 4.8 \u00b1 1.8 and \u03b4_(r.gal) = 9.5 \u00b1 2.0 for the blue and red peaks, respectively, and \u03b4_(r.gal) = 7.6 \u00b1 1.4 for the entire region. These overdensities correspond to masses of M_b = (0.76 \u00b1 0.17) x 10^(15)h^(-1) M_\u2299 M_r = (2.15 \u00b1 0.32) x 10^(15)h^(-1) M_\u2299, and M_t = (3.19 \u00b1 0.40) x 10^(15)h^(-1),M_\u2299 for the red, blue, and total peaks, respectively. We use the Small MultiDark Planck (SMDPL) simulation to identify comparably massive z ~ 3 protoclusters, and uncover the underlying structure and ultimate fate of the SSA22 protocluster. For this analysis, we construct mock redshift histograms for each simulated z ~ 3 protocluster, quantitatively comparing them with the observed SSA22 data. We find that the observed double-peaked structure in the SSA22 redshift histogram corresponds not to a single coalescing cluster, but rather the proximity of a ~ 10^(15)h^(-1) M_\u2299 protocluster and at least one \u3009 10^(14)h^(-1) M_\u2299 cluster progenitor. Such associations in the SMDPL simulation are easily understood within the framework of hierarchical clustering of dark matter halos. We finally find that the opportunity to observe such a phenomenon is incredibly rare, with an occurrence rate of 7.4h^3 Gpc^(-3).",
"doi": "10.3847/1538-4357/aa9f0f",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2018-01-10",
"series_number": "2",
"volume": "852",
"issue": "2",
"pages": "Art. No. 134"
},
{
"id": "authors:9m469-m6z49",
"collection": "authors",
"collection_id": "9m469-m6z49",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170911-124424108",
"type": "article",
"title": "A comparison of observed and simulated absorption from H I, C IV, and Si IV around z \u2248 2 star-forming galaxies suggests redshift\u2013space distortions are due to inflows",
"author": [
{
"family_name": "Turner",
"given_name": "Monica L.",
"clpid": "Turner-M-L"
},
{
"family_name": "Schaye",
"given_name": "Joop",
"clpid": "Schaye-J"
},
{
"family_name": "Crain",
"given_name": "Robert A.",
"clpid": "Crain-R-A"
},
{
"family_name": "Rudie",
"given_name": "Gwen",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "Allison",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Theuns",
"given_name": "Tom",
"clpid": "Theuns-T"
}
],
"abstract": "We study H\u2009I and metal-line absorption around z \u2248 2 star-forming galaxies by comparing an analysis of data from the Keck Baryonic Structure Survey to mock spectra generated from the Evolution and Assembly of Galaxies and their Environments (EAGLE) cosmological, hydrodynamical simulations. We extract sightlines from the simulations and compare the properties of the absorption by H\u2009I, C IV, and Si IV around simulated and observed galaxies using pixel optical depths. We mimic the resolution, pixel size, and signal-to-noise ratio of the observations, as well as the distributions of impact parameters and galaxy redshift errors. We find that the EAGLE reference model is in excellent agreement with the observations. In particular, the simulation reproduces the high metal-line optical depths found at small galactocentric distances, the optical depth enhancements out to impact parameters of 2 proper Mpc, and the prominent redshift\u2013space distortions which we find are due to peculiar velocities rather than redshift errors. The agreement is best for halo masses \u223c10^(12.0) M\u2299, for which the observed and simulated stellar masses also agree most closely. We examine the median ion mass-weighted radial gas velocities around the galaxies, and find that most of the gas is infalling, with the infall velocity depending on halo rather than stellar mass. From this, we conclude that the observed redshift\u2013space distortions are predominantly caused by infall rather than outflows.",
"doi": "10.1093/mnras/stx1616",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2017-10",
"series_number": "1",
"volume": "471",
"issue": "1",
"pages": "690-705"
},
{
"id": "authors:s0bh9-zem78",
"collection": "authors",
"collection_id": "s0bh9-zem78",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170914-155935445",
"type": "article",
"title": "The HDUV Survey: Six Lyman Continuum Emitter Candidates at z \u223c 2 Revealed by HST UV Imaging",
"author": [
{
"family_name": "Naidu",
"given_name": "R. P.",
"orcid": "0000-0003-3997-5705",
"clpid": "Naidu-R-P"
},
{
"family_name": "Oesch",
"given_name": "P. A.",
"orcid": "0000-0001-5851-6649",
"clpid": "Oesch-P-A"
},
{
"family_name": "Reddy",
"given_name": "N.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Holden",
"given_name": "B.",
"orcid": "0000-0002-6153-3076",
"clpid": "Holden-B"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Montes",
"given_name": "M.",
"orcid": "0000-0001-7847-0393",
"clpid": "Montes-M"
},
{
"family_name": "Atek",
"given_name": "H.",
"orcid": "0000-0002-7570-0824",
"clpid": "Atek-H"
},
{
"family_name": "Bouwens",
"given_name": "R. J.",
"orcid": "0000-0002-4989-2471",
"clpid": "Bouwens-R-J"
},
{
"family_name": "Carollo",
"given_name": "C. M.",
"orcid": "0000-0003-1624-7609",
"clpid": "Carollo-C-Marcella"
},
{
"family_name": "Cibinel",
"given_name": "A.",
"orcid": "0000-0003-4578-514X",
"clpid": "Cibinel-A"
},
{
"family_name": "Illingworth",
"given_name": "G. D.",
"orcid": "0000-0002-8096-2837",
"clpid": "Illingworth-G-D"
},
{
"family_name": "Labb\u00e9",
"given_name": "I.",
"orcid": "0000-0002-2057-5376",
"clpid": "Labb\u00e9-I"
},
{
"family_name": "Magee",
"given_name": "D.",
"clpid": "Magee-D-K"
},
{
"family_name": "Morselli",
"given_name": "L.",
"clpid": "Morselli-L"
},
{
"family_name": "Nelson",
"given_name": "E. J.",
"orcid": "0000-0002-7524-374X",
"clpid": "Nelson-E-J"
},
{
"family_name": "van Dokkum",
"given_name": "P. G.",
"orcid": "0000-0002-8282-9888",
"clpid": "van-Dokkum-P-G"
},
{
"family_name": "Wilkins",
"given_name": "S.",
"clpid": "Wilkins-S"
}
],
"abstract": "We present six galaxies at z ~ 2 that show evidence of Lyman continuum (LyC) emission based on the newly acquired UV imaging of the Hubble Deep UV legacy survey (HDUV) conducted with the WFC3/UVIS camera on the Hubble Space Telescope (HST). At the redshift of these sources, the HDUV F275W images partially probe the ionizing continuum. By exploiting the HST multiwavelength data available in the HDUV/GOODS fields, models of the UV spectral energy distributions, and detailed Monte Carlo simulations of the intergalactic medium absorption, we estimate the absolute ionizing photon escape fractions of these galaxies to be very high\u2014typically >60% (>13% for all sources at 90% likelihood). Our findings are in broad agreement with previous studies that found only a small fraction of galaxies with high escape fraction. These six galaxies compose the largest sample yet of LyC leaking candidates at z ~ 2 whose inferred LyC flux has been observed at HST resolution. While three of our six candidates show evidence of hosting an active galactic nucleus, two of these are heavily obscured and their LyC emission appears to originate from star-forming regions rather than the central nucleus. Extensive multiwavelength data in the GOODS fields, especially the near-IR grism spectra from the 3D-HST survey, enable us to study the candidates in detail and tentatively test some recently proposed indirect methods to probe LyC leakage. High-resolution spectroscopic follow-up of our candidates will help constrain such indirect methods, which are our only hope of studying f_(esc) at z ~ 5 - 9 in the JWST era.",
"doi": "10.3847/1538-4357/aa8863",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2017-09-20",
"series_number": "1",
"volume": "847",
"issue": "1",
"pages": "Art. No. 12"
},
{
"id": "authors:e3x5h-tj078",
"collection": "authors",
"collection_id": "e3x5h-tj078",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170505-064608864",
"type": "article",
"title": "Discovery of the most metal-poor damped Lyman-\u03b1 system",
"author": [
{
"family_name": "Cooke",
"given_name": "Ryan J.",
"orcid": "0000-0001-7653-5827",
"clpid": "Cooke-R-J"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We report the discovery and analysis of the most metal-poor damped Lyman \u03b1 (DLA) system currently known, based on observations made with the Keck HIRES spectrograph. The metal paucity of this system has only permitted the determination of three element abundances: [C/H] = \u22123.43 \u00b1 0.06, [O/H] = \u22123.05 \u00b1 0.05 and [Si/H] = \u22123.21 \u00b1 0.05, as well as an upper limit on the abundance of iron: [Fe/H] \u2264 \u22122.81. This DLA is among the most carbon-poor environment currently known with detectable metals. By comparing the abundance pattern of this DLA to detailed models of metal-free nucleosynthesis, we find that the chemistry of the gas is consistent with the yields of a 20.5\u2009M_\u2299 metal-free star that ended its life as a core-collapse supernova; the abundances we measure are inconsistent with the yields of pair-instability supernovae. Such a tight constraint on the mass of the progenitor Population III star is afforded by the well-determined C/O ratio, which we show depends almost monotonically on the progenitor mass when the kinetic energy of the supernova explosion is Eexp \u2273 1.5 \u00d7 10^(51)\u2009erg. We find that the DLA presented here has just crossed the critical 'transition discriminant' threshold, rendering the DLA gas now suitable for low mass star formation. We also discuss the chemistry of this system in the context of recent models that suggest some of the most metal-poor DLAs are the precursors of the 'first galaxies', and are the antecedents of the ultrafaint dwarf galaxies.",
"doi": "10.1093/mnras/stx037",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2017-05",
"series_number": "1",
"volume": "467",
"issue": "1",
"pages": "802-811"
},
{
"id": "authors:q98a4-0x079",
"collection": "authors",
"collection_id": "q98a4-0x079",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170420-143345464",
"type": "article",
"title": "iPTF16geu: A multiply imaged, gravitationally lensed type Ia supernova",
"author": [
{
"family_name": "Goobar",
"given_name": "A.",
"orcid": "0000-0002-4163-4996",
"clpid": "Goobar-A"
},
{
"family_name": "Amanullah",
"given_name": "R.",
"orcid": "0000-0002-5559-9351",
"clpid": "Amanullah-R"
},
{
"family_name": "Kulkarni",
"given_name": "S. R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Nugent",
"given_name": "P. E.",
"orcid": "0000-0002-3389-0586",
"clpid": "Nugent-P-E"
},
{
"family_name": "Johansson",
"given_name": "J.",
"orcid": "0000-0001-5975-290X",
"clpid": "Johansson-J"
},
{
"family_name": "Steidel",
"given_name": "C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Lawrence",
"given_name": "D.",
"clpid": "Lawrence-D-J"
},
{
"family_name": "M\u00f6rtsell",
"given_name": "E.",
"clpid": "M\u00f6rtsell-E"
},
{
"family_name": "Quimby",
"given_name": "R.",
"orcid": "0000-0001-9171-5236",
"clpid": "Quimby-R-M"
},
{
"family_name": "Blagorodnova",
"given_name": "N.",
"orcid": "0000-0003-0901-1606",
"clpid": "Blagorodnova-N"
},
{
"family_name": "Brandeker",
"given_name": "A.",
"clpid": "Brandeker-A"
},
{
"family_name": "Cao",
"given_name": "Y.",
"orcid": "0000-0002-8036-8491",
"clpid": "Cao-Yi"
},
{
"family_name": "Cooray",
"given_name": "A.",
"orcid": "0000-0002-3892-0190",
"clpid": "Cooray-A"
},
{
"family_name": "Ferretti",
"given_name": "R.",
"orcid": "0000-0001-7814-5814",
"clpid": "Ferretti-R"
},
{
"family_name": "Fremling",
"given_name": "C.",
"orcid": "0000-0002-4223-103X",
"clpid": "Fremling-C"
},
{
"family_name": "Hangard",
"given_name": "L.",
"clpid": "Hangard-L"
},
{
"family_name": "Kasliwal",
"given_name": "M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Kupfer",
"given_name": "T.",
"orcid": "0000-0002-6540-1484",
"clpid": "Kupfer-T"
},
{
"family_name": "Lunnan",
"given_name": "R.",
"orcid": "0000-0001-9454-4639",
"clpid": "Lunnan-R"
},
{
"family_name": "Masci",
"given_name": "F.",
"orcid": "0000-0002-8532-9395",
"clpid": "Masci-F-J"
},
{
"family_name": "Miller",
"given_name": "A. A.",
"orcid": "0000-0001-9515-478X",
"clpid": "Miller-A-A"
},
{
"family_name": "Nayyeri",
"given_name": "H.",
"orcid": "0000-0001-8242-9983",
"clpid": "Nayyeri-H"
},
{
"family_name": "Neill",
"given_name": "J. D.",
"orcid": "0000-0002-0466-1119",
"clpid": "Neill-J-D"
},
{
"family_name": "Ofek",
"given_name": "E. O.",
"orcid": "0000-0002-6786-8774",
"clpid": "Ofek-E-O"
},
{
"family_name": "Papadogiannakis",
"given_name": "S.",
"orcid": "0000-0003-0783-3323",
"clpid": "Papadogiannakis-S"
},
{
"family_name": "Petrushevska",
"given_name": "T.",
"orcid": "0000-0003-4743-1679",
"clpid": "Petrushevska-T"
},
{
"family_name": "Ravi",
"given_name": "V.",
"orcid": "0000-0002-7252-5485",
"clpid": "Ravi-Vikram"
},
{
"family_name": "Sollerman",
"given_name": "J.",
"orcid": "0000-0003-1546-6615",
"clpid": "Sollerman-J"
},
{
"family_name": "Sullivan",
"given_name": "M.",
"orcid": "0000-0001-9053-4820",
"clpid": "Sullivan-Mark"
},
{
"family_name": "Taddia",
"given_name": "F.",
"orcid": "0000-0002-2387-6801",
"clpid": "Taddia-F"
},
{
"family_name": "Walters",
"given_name": "R.",
"orcid": "0000-0002-1835-6078",
"clpid": "Walters-R"
},
{
"family_name": "Wilson",
"given_name": "D. M.",
"orcid": "0000-0001-6002-423X",
"clpid": "Wilson-D-M"
},
{
"family_name": "Yan",
"given_name": "L.",
"orcid": "0000-0003-1710-9339",
"clpid": "Yan-Lin"
},
{
"family_name": "Yaron",
"given_name": "O.",
"orcid": "0000-0002-0301-8017",
"clpid": "Yaron-O"
}
],
"abstract": "We report the discovery of a multiply imaged, gravitationally lensed type Ia supernova, iPTF16geu (SN 2016geu), at redshift z = 0.409. This phenomenon was identified because the light from the stellar explosion was magnified more than 50 times by the curvature of space around matter in an intervening galaxy. We used high-spatial-resolution observations to resolve four images of the lensed supernova, approximately 0.3 arc seconds from the center of the foreground galaxy. The observations probe a physical scale of ~1 kiloparsec, smaller than is typical in other studies of extragalactic gravitational lensing. The large magnification and symmetric image configuration imply close alignment between the lines of sight to the supernova and to the lens. The relative magnifications of the four images provide evidence for substructures in the lensing galaxy.",
"doi": "10.1126/science.aal2729",
"issn": "0036-8075",
"publisher": "American Association for the Advancement of Science",
"publication": "Science",
"publication_date": "2017-04-21",
"series_number": "6335",
"volume": "356",
"issue": "6335",
"pages": "291-295"
},
{
"id": "authors:1jyw6-vm494",
"collection": "authors",
"collection_id": "1jyw6-vm494",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170421-131659519",
"type": "article",
"title": "Extreme Variability in a Broad Absorption Line Quasar",
"author": [
{
"family_name": "Stern",
"given_name": "Daniel",
"orcid": "0000-0003-2686-9241",
"clpid": "Stern-D"
},
{
"family_name": "Graham",
"given_name": "Matthew J.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Arav",
"given_name": "Nahum",
"clpid": "Arav-N"
},
{
"family_name": "Djorgovski",
"given_name": "S. G.",
"orcid": "0000-0002-0603-3087",
"clpid": "Djorgovski-S-G"
},
{
"family_name": "Chamberlain",
"given_name": "Carter",
"clpid": "Chamberlain-C"
},
{
"family_name": "Barth",
"given_name": "Aaron J.",
"orcid": "0000-0002-3026-0562",
"clpid": "Barth-A-J"
},
{
"family_name": "Donalek",
"given_name": "Ciro",
"clpid": "Donalek-C"
},
{
"family_name": "Drake",
"given_name": "Andrew J.",
"clpid": "Drake-A-J"
},
{
"family_name": "Glikman",
"given_name": "Eilat",
"orcid": "0000-0003-0489-3750",
"clpid": "Glikman-E"
},
{
"family_name": "Jun",
"given_name": "Hyunsung D.",
"orcid": "0000-0003-1470-5901",
"clpid": "Jun-Hyunsung-David"
},
{
"family_name": "Mahabal",
"given_name": "Ashish A.",
"orcid": "0000-0003-2242-0244",
"clpid": "Mahabal-A-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "CRTS J084133.15+200525.8 is an optically bright quasar at z = 2.345 that has shown extreme spectral variability over the past decade. Photometrically, the source had a visual magnitude of V ~ 17.3 between 2002 and 2008. Then, over the following five years, the source slowly brightened by approximately one magnitude, to V ~ 16.2. Only ~1 in 10,000 quasars show such extreme variability, as quantified by the extreme parameters derived for this quasar assuming a damped random walk model. A combination of archival and newly acquired spectra reveal the source to be an iron low-ionization broad absorption line quasar with extreme changes in its absorption spectrum. Some absorption features completely disappear over the 9 years of optical spectra, while other features remain essentially unchanged. We report the first definitive redshift for this source, based on the detection of broad H\u03b1 in a Keck/MOSFIRE spectrum. Absorption systems separated by several 1000 km s^(\u22121) in velocity show coordinated weakening in the depths of their troughs as the continuum flux increases. We interpret the broad absorption line variability to be due to changes in photoionization, rather than due to motion of material along our line of sight. This source highlights one sort of rare transition object that astronomy will now be finding through dedicated time-domain surveys.",
"doi": "10.3847/1538-4357/aa683c",
"issn": "1538-4357",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2017-04-20",
"series_number": "2",
"volume": "839",
"issue": "2",
"pages": "Art. No. 106"
},
{
"id": "authors:pj0zz-egp71",
"collection": "authors",
"collection_id": "pj0zz-egp71",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170221-162631848",
"type": "article",
"title": "Nebular Emission Line Ratios in z \u2243 2\u20133 Star-forming Galaxies with KBSS-MOSFIRE: Exploring the Impact of Ionization, Excitation, and Nitrogen-to-Oxygen Ratio",
"author": [
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
}
],
"abstract": "We present a detailed study of the rest-optical (3600\u20137000 \u00c5) nebular spectra of ~380 star-forming galaxies at z \u2243 2\u20133, obtained with Keck/Multi-object Spectrometer for Infrared Exploration (MOSFIRE) as part of the Keck Baryonic Structure Survey (KBSS). The KBSS-MOSFIRE sample is representative of star-forming galaxies at these redshifts, with stellar masses M_* = M^9 \u2013 M^(11.5) M_\u2299 and star formation rates SFR = 3\u20131000 M_\u2299 yr^(-1). We focus on robust measurements of many strong diagnostic emission lines for individual galaxies: [O II]\u03bb\u03bb3727, 3729, [Ne III]\u03bb3869, H\u03b2, [O III]\u03bb\u03bb 4960, 5008, [N II]\u03bb\u03bb 6549, 6585, H\u03b1, and [S II]\u03bb\u03bb6718, 6732. Comparisons with observations of typical local galaxies from the Sloan Digital Sky Survey and between subsamples of KBSS-MOSFIRE show that high-redshift galaxies exhibit a number of significant differences in addition to the well-known offset in log([O III]\u03bb5008/H\u03b2) and log([N II]\u03bb6585/H\u03b1). We argue that the primary difference between H II regions in z ~ 2.3 galaxies and those at z ~ 0 is an enhancement in the degree of nebular excitation, as measured by [O III]/H\u03b2 and R23 \u2261 log [([O III]\u03bb\u03bb4960, 5008+[O II]\u03bb\u03bb3727, 3729)/H\u03b2]. At the same time, KBSS-MOSFIRE galaxies are ~10 times more massive than z ~ 0 galaxies with similar ionizing spectra and have higher N/O (likely accompanied by higher O/H) at fixed excitation. These results indicate the presence of harder ionizing radiation fields at fixed N/O and O/H relative to typical z ~ 0 galaxies, consistent with Fe-poor stellar population models that include massive binaries, and highlight a population of massive, high-specific star formation rate galaxies at high redshift with systematically different star formation histories than galaxies of similar stellar mass today.",
"doi": "10.3847/1538-4357/836/2/164",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2017-02-17",
"series_number": "2",
"volume": "836",
"issue": "2",
"pages": "Art. No. 164"
},
{
"id": "authors:mpsdx-2xf13",
"collection": "authors",
"collection_id": "mpsdx-2xf13",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170127-143159985",
"type": "article",
"title": "PTF1 J082340.04+081936.5: A Hot Subdwarf B Star with a Low-mass White Dwarf Companion in an 87-minute Orbit",
"author": [
{
"family_name": "Kupfer",
"given_name": "Thomas",
"orcid": "0000-0002-6540-1484",
"clpid": "Kupfer-T"
},
{
"family_name": "van Roestel",
"given_name": "Jan",
"orcid": "0000-0002-2626-2872",
"clpid": "van-Roestel-J"
},
{
"family_name": "Brooks",
"given_name": "Jared",
"clpid": "Brooks-J"
},
{
"family_name": "Geier",
"given_name": "Stephan",
"orcid": "0000-0002-3948-9339",
"clpid": "Geier-S"
},
{
"family_name": "Marsh",
"given_name": "Tom R.",
"orcid": "0000-0002-2498-7589",
"clpid": "Marsh-T-R"
},
{
"family_name": "Groot",
"given_name": "Paul J.",
"orcid": "0000-0002-4488-726X",
"clpid": "Groot-P-J"
},
{
"family_name": "Bloemen",
"given_name": "Steven",
"clpid": "Bloemen-S"
},
{
"family_name": "Prince",
"given_name": "Thomas A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Bellm",
"given_name": "Eric",
"orcid": "0000-0001-8018-5348",
"clpid": "Bellm-E-C"
},
{
"family_name": "Heber",
"given_name": "Ulrich",
"orcid": "0000-0001-7798-6769",
"clpid": "Heber-U"
},
{
"family_name": "Bildsten",
"given_name": "Lars",
"clpid": "Bildsten-L"
},
{
"family_name": "Miller",
"given_name": "Adam A.",
"orcid": "0000-0001-9515-478X",
"clpid": "Miller-A-A"
},
{
"family_name": "Dyer",
"given_name": "Martin J.",
"clpid": "Dyer-M-J"
},
{
"family_name": "Dhillon",
"given_name": "Vik S.",
"clpid": "Dhillon-V-S"
},
{
"family_name": "Green",
"given_name": "Matthew",
"clpid": "Green-M"
},
{
"family_name": "Irawati",
"given_name": "Puji",
"clpid": "Irawati-P"
},
{
"family_name": "Laher",
"given_name": "Russ",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Littlefair",
"given_name": "Stuart P.",
"orcid": "0000-0001-7221-855X",
"clpid": "Littlefair-S-P"
},
{
"family_name": "Shupe",
"given_name": "David L.",
"orcid": "0000-0003-4401-0430",
"clpid": "Shupe-David-L"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rattansoon",
"given_name": "Somsawat",
"clpid": "Rattansoon-S"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "We present the discovery of the hot subdwarf B star (sdB) binary PTF1 J082340.04+081936.5. The system has an orbital period of P_(orb) = 87.49668(1) minutes (0.060761584(10) days), making it the second-most compact sdB binary known. The light curve shows ellipsoidal variations. Under the assumption that the sdB primary is synchronized with the orbit, we find a mass of M_(sdB) = 0.45_(-0.07)^(+0.09) M_\u2299, a companion white dwarf mass of M_(WD) = 0.46_(-0.09)^(+0.12) M_\u2299, and a mass ratio of q = M_(WD)/M_(sdB) = 1.03_(-0.08)^(+0.10). The future evolution was calculated using the MESA stellar evolution code. Adopting a canonical sdB mass of M_(sdB) = 0.47 M_\u2299, we find that the sdB still burns helium at the time it will fill its Roche lobe if the orbital period was less than 106 minutes at the exit from the last common envelope (CE) phase. For longer CE exit periods, the sdB will have stopped burning helium and turned into a C/O white dwarf at the time of contact. Comparing the spectroscopically derived log g and T_(eff) with our MESA models, we find that an sdB model with a hydrogen envelope mass of 5 x 10^(-4) M_\u2299 matches the measurements at a post-CE age of 94 Myr, corresponding to a post-CE orbital period of 109 minutes, which is close to the limit to start accretion while the sdB is still burning helium.",
"doi": "10.3847/1538-4357/835/2/131",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2017-02-01",
"series_number": "2",
"volume": "835",
"issue": "2",
"pages": "Art. No. 131"
},
{
"id": "authors:ypbf9-2gq76",
"collection": "authors",
"collection_id": "ypbf9-2gq76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170125-134707645",
"type": "article",
"title": "ALMA Deep Field in SSA22: Source Catalog and Number Counts",
"author": [
{
"family_name": "Umehata",
"given_name": "Hideki",
"orcid": "0000-0003-1937-0573",
"clpid": "Umehata-Hideki"
},
{
"family_name": "Tamura",
"given_name": "Yoichi",
"orcid": "0000-0003-4807-8117",
"clpid": "Tamura-Yoichi"
},
{
"family_name": "Kohno",
"given_name": "Kotaro",
"orcid": "0000-0002-4052-2394",
"clpid": "Kohno-Kotaro"
},
{
"family_name": "Ivison",
"given_name": "R. J.",
"orcid": "0000-0001-5118-1313",
"clpid": "Ivison-Rob-J"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Hatsukade",
"given_name": "Bunyo",
"orcid": "0000-0001-6469-8725",
"clpid": "Hatsukade-Bunyo"
},
{
"family_name": "Nakanishi",
"given_name": "Kouichiro",
"orcid": "0000-0002-6939-0372",
"clpid": "Nakanishi-Kouichiro"
},
{
"family_name": "Kato",
"given_name": "Yuta",
"clpid": "Kato-Yuta"
},
{
"family_name": "Ikarashi",
"given_name": "Soh",
"clpid": "Ikarashi-Soh"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"orcid": "0000-0003-1747-2891",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Fujimoto",
"given_name": "Seiji",
"orcid": "0000-0001-7201-5066",
"clpid": "Fujimoto-Seiji"
},
{
"family_name": "Iono",
"given_name": "Daisuke",
"orcid": "0000-0002-2364-0823",
"clpid": "Iono-Daisuke"
},
{
"family_name": "Lee",
"given_name": "Minju",
"clpid": "Lee-Minju"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Saito",
"given_name": "Tomoki",
"clpid": "Saito-Tomoki"
},
{
"family_name": "Alexander",
"given_name": "D. M.",
"orcid": "0000-0002-5896-6313",
"clpid": "Alexander-David-M"
},
{
"family_name": "Yun",
"given_name": "Min S.",
"orcid": "0000-0001-7095-7543",
"clpid": "Yun-Min-S"
},
{
"family_name": "Kubo",
"given_name": "Mariko",
"orcid": "0000-0002-7598-5292",
"clpid": "Kubo-Mariko"
}
],
"abstract": "We present results from a deep 2' \u00d7 3' (comoving scale of 3.7 Mpc \u00d7 5.5 Mpc at z = 3) survey at 1.1 mm, taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in the SSA22 field. We observe the core region of a z = 3.09 protocluster, achieving a typical rms sensitivity of 60 \u03bcJy beam^(\u22121) at a spatial resolution of 0\"7. We detect 18 robust ALMA sources at a signal-to-noise ratio (S/N) > 5. Comparison between the ALMA map and a 1.1 mm map, taken with the AzTEC camera on the Atacama Submillimeter Telescope Experiment (ASTE), indicates that three submillimeter sources discovered by the AzTEC/ASTE survey are resolved into eight individual submillimeter galaxies (SMGs) by ALMA. At least 10 of our 18 ALMA SMGs have spectroscopic redshifts of z sime 3.09, placing them in the protocluster. This shows that a number of dusty starburst galaxies are forming simultaneously in the core of the protocluster. The nine brightest ALMA SMGs with S/N > 10 have a median intrinsic angular size of 0.\"32_(-0.06)^(+0.13)(2.4_(-0.4^(+1.0 physical kpc at z = 3.09), which is consistent with previous size measurements of SMGs in other fields. As expected, the source counts show a possible excess compared to the counts in the general fields at S_(1.1mm) \u2265 1.0 mJy, due to the protocluster. Our contiguous mm mapping highlights the importance of large-scale structures on the formation of dusty starburst galaxies.",
"doi": "10.3847/1538-4357/835/1/98",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2017-01-20",
"series_number": "1",
"volume": "835",
"issue": "1",
"pages": "Art. No. 98"
},
{
"id": "authors:nbj1s-gbp47",
"collection": "authors",
"collection_id": "nbj1s-gbp47",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170120-133954598",
"type": "article",
"title": "ALMA Reveals Strong [C II] Emission in a Galaxy Embedded in a Giant Ly\u03b1 Blob at z = 3.1",
"author": [
{
"family_name": "Umehata",
"given_name": "Hideki",
"orcid": "0000-0003-1937-0573",
"clpid": "Umehata-Hideki"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"orcid": "0000-0003-1747-2891",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Tamura",
"given_name": "Yoichi",
"orcid": "0000-0003-4807-8117",
"clpid": "Tamura-Yoichi"
},
{
"family_name": "Kohno",
"given_name": "Kotaro",
"orcid": "0000-0002-4052-2394",
"clpid": "Kohno-Kotaro"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Ivison",
"given_name": "R. J.",
"orcid": "0000-0001-5118-1313",
"clpid": "Ivison-Rob-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chapman",
"given_name": "Scott C.",
"orcid": "0000-0002-8487-3153",
"clpid": "Chapman-Scott-C"
},
{
"family_name": "Geach",
"given_name": "James E.",
"orcid": "0000-0003-4964-4635",
"clpid": "Geach-James-E"
},
{
"family_name": "Hayes",
"given_name": "Matthew",
"orcid": "0000-0001-8587-218X",
"clpid": "Hayes-Matthew"
},
{
"family_name": "Nagao",
"given_name": "Tohru",
"orcid": "0000-0002-7402-5441",
"clpid": "Nagao-Tohru"
},
{
"family_name": "Ao",
"given_name": "Yiping",
"orcid": "0000-0003-3139-2724",
"clpid": "Ao-Yiping"
},
{
"family_name": "Kawabe",
"given_name": "Ryohei",
"orcid": "0000-0002-8049-7525",
"clpid": "Kawabe-Ryohei"
},
{
"family_name": "Yun",
"given_name": "Min S.",
"orcid": "0000-0001-7095-7543",
"clpid": "Yun-Min-S"
},
{
"family_name": "Hatsukade",
"given_name": "Bunyo",
"orcid": "0000-0001-6469-8725",
"clpid": "Hatsukade-Bunyo"
},
{
"family_name": "Kubo",
"given_name": "Mariko",
"orcid": "0000-0002-7598-5292",
"clpid": "Kubo-Mariko"
},
{
"family_name": "Kato",
"given_name": "Yuta",
"clpid": "Kato-Yuta"
},
{
"family_name": "Saito",
"given_name": "Tomoki",
"clpid": "Saito-Tomoki"
},
{
"family_name": "Ikarashi",
"given_name": "Soh",
"clpid": "Ikarashi-Soh"
},
{
"family_name": "Nakanishi",
"given_name": "Kouichiro",
"orcid": "0000-0002-6939-0372",
"clpid": "Nakanishi-Kouichiro"
},
{
"family_name": "Lee",
"given_name": "Minju",
"clpid": "Lee-Minju"
},
{
"family_name": "Izumi",
"given_name": "Takuma",
"clpid": "Izumi-Takuma"
},
{
"family_name": "Mori",
"given_name": "Masao",
"clpid": "Mori-Masao"
},
{
"family_name": "Ouchi",
"given_name": "Masami",
"orcid": "0000-0002-1049-6658",
"clpid": "Ouchi-Masami"
}
],
"abstract": "We report the result from observations conducted with the Atacama Large Millimeter/submillimeter Array (ALMA) to detect [C ii] 158 \u03bcm fine structure line emission from galaxies embedded in one of the most spectacular Ly\u03b1 blobs (LABs) at z = 3.1, SSA22-LAB1. Of three dusty star-forming galaxies previously discovered by ALMA 860 \u03bcm dust continuum survey toward SSA22-LAB1, we detected the [C ii] line from one, LAB1-ALMA3 at z = 3.0993 \u00b1 0.0004. No line emission was detected, associated with the other ALMA continuum sources or from three rest-frame UV/optical selected z_(spec) \u2243 3.1 galaxies within the field of view. For LAB1-ALMA3, we find relatively bright [C ii] emission compared to the infrared luminosity (L_([C ii])/L_(IR) \u2248 0.01) and an extremely high [C ii] 158 \u03bcm and [N ii] 205 \u03bcm emission line ratio (L_([C ii])/L_([N ii]) > 55). The relatively strong [C ii] emission may be caused by abundant photodissociation regions and sub-solar metallicity, or by shock heating. The origin of the unusually strong [C ii] emission could be causally related to the location within the giant LAB, although the relationship between extended Ly\u03b1 emission and interstellar medium conditions of associated galaxies is yet to be understand.",
"doi": "10.3847/2041-8213/834/2/L16",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2017-01-10",
"series_number": "2",
"volume": "834",
"issue": "2",
"pages": "Art. No. L16"
},
{
"id": "authors:f7j21-mm492",
"collection": "authors",
"collection_id": "f7j21-mm492",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-114300659",
"type": "article",
"title": "The Rest-frame Optical Spectroscopic Properties of Ly\u03b1-emitters at z~2.5: The Physical Origins of Strong Ly\u03b1 Emission",
"author": [
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
}
],
"abstract": "We present the rest-frame optical spectroscopic properties of 60 faint (R_(AB) ~ 27; L ~ 0.1 L_*) Ly\u03b1-selected galaxies (LAEs) at z \u2248 2.56. These LAEs also have rest-UV spectra of their Ly\u03b1 emission line morphologies, which trace the effects of interstellar and circumgalactic gas on the escape of Ly\u03b1 photons. We find that the LAEs have diverse rest-optical spectra, but their average spectroscopic properties are broadly consistent with the extreme low-metallicity end of the populations of continuum-selected galaxies selected at z \u2248 2\u20133. In particular, the LAEs have extremely high [O iii] \u03bb5008/H\u03b2 ratios (log([O iii]/H\u03b2) ~ 0.8) and low [N ii] \u03bb6585/H\u03b1 ratios (log([N ii]/H\u03b1) < 1.15). Coupled with a detection of the [O iii] \u03bb4364 auroral line, these measurements indicate that the star-forming regions in faint LAEs are characterized by high electron temperatures (T_e \u2248 1.8 \u00d7 10^4 K), low oxygen abundances (12 + log(O/H) \u2248 8.04, Z_(neb) \u2248 0.22Z_\u2299), and high excitations with respect to their more luminous continuum-selected analogs. Several of our faintest LAEs have line ratios consistent with even lower metallicities, including six with 12 + log(O/H) \u2248 6.9\u20137.4 (Z_(neb) \u2248 0.02\u20130.05Z_\u2299). We interpret these observations in light of new models of stellar evolution (including binary interactions) that have been shown to produce long-lived populations of hot, massive stars at low metallicities. We find that strong, hard ionizing continua are required to reproduce our observed line ratios, suggesting that faint galaxies are efficient producers of ionizing photons and important analogs of reionization-era galaxies. Furthermore, we investigate the physical trends accompanying Ly\u03b1 emission across the largest current sample of combined Ly\u03b1 and rest-optical galaxy spectroscopy, including both the 60 KBSS-Ly\u03b1 LAEs and 368 more luminous galaxies at similar redshifts. We find that the net Ly\u03b1 emissivity (parameterized by the Ly\u03b1 equivalent width) is strongly correlated with nebular excitation and ionization properties and weakly correlated with dust attenuation, suggesting that metallicity plays a strong role in determining the observed properties of these galaxies by modulating their stellar spectra, nebular excitation, and dust content.",
"doi": "10.3847/0004-637X/832/2/171",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2016-12-01",
"series_number": "2",
"volume": "832",
"issue": "2",
"pages": "Art. No. 171"
},
{
"id": "authors:r49qx-3rp08",
"collection": "authors",
"collection_id": "r49qx-3rp08",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161116-125343348",
"type": "article",
"title": "ALMA Observations of Ly\u03b1 Blob 1: Halo Substructure Illuminated from Within",
"author": [
{
"family_name": "Geach",
"given_name": "J. E.",
"orcid": "0000-0003-4964-4635",
"clpid": "Geach-J-E"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present new Atacama Large Millimeter/Submillimeter Array (ALMA) 850 \u03bcm continuum observations of the original Ly\u03b1 Blob (LAB) in the SSA22 field at z = 3.1 (SSA22-LAB01). The ALMA map resolves the previously identified submillimeter source into three components with a total flux density of S_(850) = 1.68 \u00b1 0.06 mJy, corresponding to a star-formation rate of ~150 M \u2299 yr^(\u22121). The submillimeter sources are associated with several faint (m \u2248 27 mag) rest-frame ultraviolet sources identified in Hubble Space Telescope Imaging Spectrograph (STIS) clear filter imaging (\u03bb \u2248 5850 \u00c5). One of these companions is spectroscopically confirmed with the Keck Multi-Object Spectrometer For Infra-Red Exploration to lie within 20 projected kpc and 250 km s^(\u22121) of one of the ALMA components. We postulate that some of these STIS sources represent a population of low-mass star-forming satellites surrounding the central submillimeter sources, potentially contributing to their growth and activity through accretion. Using a high-resolution cosmological zoom simulation of a 10^(13) M\u2299 halo at z = 3, including stellar, dust, and Ly\u03b1 radiative transfer, we can model the ALMA+STIS observations and demonstrate that Ly\u03b1 photons escaping from the central submillimeter sources are expected to resonantly scatter in neutral hydrogen, the majority of which is predicted to be associated with halo substructure. We show how this process gives rise to extended Ly\u03b1 emission with similar surface brightness and morphology to observed giant LABs.",
"doi": "10.3847/0004-637X/832/1/37",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2016-11-20",
"series_number": "1",
"volume": "832",
"issue": "1",
"pages": "Art. No. 37"
},
{
"id": "authors:16ggw-cw493",
"collection": "authors",
"collection_id": "16ggw-cw493",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-133421969",
"type": "article",
"title": "SN Refsdal: Classification as a Luminous and Blue SN 1987A-like Type II Supernova",
"author": [
{
"family_name": "Kelly",
"given_name": "P. L.",
"orcid": "0000-0003-3142-997X",
"clpid": "Kelly-P-L"
},
{
"family_name": "Brammer",
"given_name": "G.",
"clpid": "Brammer-G"
},
{
"family_name": "Selsing",
"given_name": "J.",
"clpid": "Selsing-J"
},
{
"family_name": "Foley",
"given_name": "R. J.",
"clpid": "Foley-R-J"
},
{
"family_name": "Hjorth",
"given_name": "J.",
"orcid": "0000-0002-4571-2306",
"clpid": "Hjorth-J"
},
{
"family_name": "Rodney",
"given_name": "S. A.",
"orcid": "0000-0003-1947-687X",
"clpid": "Rodney-S-A"
},
{
"family_name": "Christensen",
"given_name": "L.",
"clpid": "Christensen-L-E"
},
{
"family_name": "Strolger",
"given_name": "L.-G.",
"clpid": "Strolger-L-G"
},
{
"family_name": "Filippenko",
"given_name": "A. V.",
"orcid": "0000-0003-3460-0103",
"clpid": "Filippenko-A-V"
},
{
"family_name": "Treu",
"given_name": "T.",
"orcid": "0000-0002-8460-0390",
"clpid": "Treu-Tommaso"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "A.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Riess",
"given_name": "A. G.",
"clpid": "Riess-A-G"
},
{
"family_name": "Zitrin",
"given_name": "A.",
"orcid": "0000-0002-0350-4488",
"clpid": "Zitrin-Adi"
},
{
"family_name": "Schmidt",
"given_name": "K. B.",
"clpid": "Schmidt-K-B"
},
{
"family_name": "Brada\u010d",
"given_name": "M.",
"clpid": "Brada\u010d-M"
},
{
"family_name": "Jha",
"given_name": "S. W.",
"orcid": "0000-0001-8738-6011",
"clpid": "Jha-S-W"
},
{
"family_name": "Graham",
"given_name": "M. L.",
"orcid": "0000-0002-9154-3136",
"clpid": "Graham-M-L"
},
{
"family_name": "McCully",
"given_name": "C.",
"orcid": "0000-0001-5807-7893",
"clpid": "McCully-C"
},
{
"family_name": "Graur",
"given_name": "O.",
"clpid": "Graur-O"
},
{
"family_name": "Weiner",
"given_name": "B. J.",
"clpid": "Weiner-B-J"
},
{
"family_name": "Silverman",
"given_name": "J. M.",
"orcid": "0000-0003-3325-3365",
"clpid": "Silverman-J-M"
},
{
"family_name": "Taddia",
"given_name": "F.",
"orcid": "0000-0002-2387-6801",
"clpid": "Taddia-F"
}
],
"abstract": "We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN 1987A-like SNe, and we find strong evidence for a broad H\u03b1 P-Cygni profile and Na I D absorption in the HST grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe IIn, largely powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and strong H\u03b1 and Na I D absorption. From the grism spectrum, we measure an H\u03b1 expansion velocity consistent with those of SN 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the H\u03b1 emission of the WFC3 and X-shooter spectra, separated by ~2.5 months in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, photometry of SN Refsdal favors bluer B \u2212 V and V \u2212 R colors and one of the largest luminosities for the assumed range of potential magnifications. The evolution of the light curve at late times will provide additional evidence about the potential existence of any substantial circumstellar material. Using MOSFIRE and X-shooter spectra, we estimate a subsolar host-galaxy metallicity (8.3 \u00b1 0.1 dex and <8.4 dex, respectively) near the explosion site.",
"doi": "10.3847/0004-637X/831/2/205",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2016-11-10",
"series_number": "2",
"volume": "831",
"issue": "2",
"pages": "Art. No. 205"
},
{
"id": "authors:5f12m-5ze74",
"collection": "authors",
"collection_id": "5f12m-5ze74",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161027-140937011",
"type": "article",
"title": "The Lyman Continuum Escape Fraction of the Cosmic Horseshoe: A Test of Indirect Estimates",
"author": [
{
"family_name": "Vasei",
"given_name": "Kaveh",
"clpid": "Vasei-Kaveh"
},
{
"family_name": "Siana",
"given_name": "Brian",
"orcid": "0000-0002-4935-9511",
"clpid": "Siana-Brian-D"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Quider",
"given_name": "Anna M.",
"clpid": "Quider-A-M"
},
{
"family_name": "Alavi",
"given_name": "Anahita",
"orcid": "0000-0002-8630-6435",
"clpid": "Alavi-A"
},
{
"family_name": "Rafelski",
"given_name": "Marc",
"orcid": "0000-0002-9946-4731",
"clpid": "Rafelski-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Lewis",
"given_name": "Geraint F.",
"clpid": "Lewis-G-F"
}
],
"abstract": "High-redshift star-forming galaxies are likely responsible for the reionization of the universe, yet direct detection of their escaping ionizing (Lyman continuum [LyC]) photons has proven to be extremely challenging. In this study, we search for escaping LyC of the Cosmic Horseshoe, a gravitationally lensed, star-forming galaxy at z = 2.38 with a large magnification of ~24. Transmission at wavelengths of low-ionization interstellar absorption lines in the rest-frame ultraviolet suggests a patchy, partially transparent interstellar medium. This makes it an ideal candidate for direct detection of the LyC. We obtained a 10-orbit Hubble near-UV image using the Wide Field Camera 3 (WFC3)/UVIS F275W filter that probes wavelengths just below the Lyman limit at the redshift of the Horseshoe in an attempt to detect escaping LyC radiation. After fully accounting for the uncertainties in the opacity of the intergalactic medium (IGM) and accounting for the charge transfer inefficiency in the WFC3 CCDs, we find a 3 \u03c3 upper limit for the relative escape fraction of f_(esc,rel) < 0.08. This value is a factor of five lower than the value (0.4) predicted by the 40% transmission in the low-ion absorption lines. Though possible, it is unlikely that the nondetection is due to a high-opacity line of sight through the IGM < 20% chance). We discuss several possible causes for the discrepancy between the escape fraction and the covering fraction and consider the implications for future attempts at both direct LyC detection and indirect estimates of the escape fraction.",
"doi": "10.3847/0004-637X/831/1/38",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2016-11-01",
"series_number": "1",
"volume": "831",
"issue": "1",
"pages": "Art. No. 38"
},
{
"id": "authors:a2t40-09w45",
"collection": "authors",
"collection_id": "a2t40-09w45",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161012-142337724",
"type": "article",
"title": "A High Fraction of Ly\u03b1-Emitters Among Galaxies with Extreme Emission Line Ratios at z ~ 2",
"author": [
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
}
],
"abstract": "Star-forming galaxies form a sequence in the [O III] \u03bb5007/H\u03b2 versus [N II] \u03bb6584/H\u0251 diagnostic diagram, with low-metallicity, highly ionized galaxies falling in the upper left corner. Drawing from a large sample of UV-selected star-forming galaxies at z ~ 2 with rest-frame optical nebular emission line measurements from Keck-MOSFIRE, we select the extreme ~5% of the galaxies lying in this upper left corner, requiring log([NII]/H\u03b2) \u2a7d -1.1 and log([O III]/H\u03b2) \u2a7e/0.75. These cuts identify galaxies with 12 + log(O/H \u227e 8.0, when oxygen abundances are measured via the O3N2 diagnostic. We study the Ly\u03b1 properties of the resulting sample of 14 galaxies. The mean (median) rest-frame Ly\u03b1 equivalent width is 39 (36) \u00c5, and 11 of the 14 objects (79%) are Ly\u03b1 emitters (LAEs) with W_(Ly\u03b1) > 20 \u00c5. We compare the equivalent width distribution of a sample of 522 UV-selected galaxies at 2.0 < z < 2.6 identified without regard to their optical line ratios; this sample has mean (median) Ly\u03b1 equivalent width \u22121 (\u22124) \u00c5, and only 9% of these galaxies qualify as LAEs. The extreme galaxies typically have lower attenuation at Ly\u03b1 than those in the comparison sample and have ~50% lower median oxygen abundances. Both factors are likely to facilitate the escape of Ly\u03b1: in less dusty galaxies Ly\u03b1 photons are less likely to be absorbed during multiple scatterings, while the harder ionizing spectrum and higher ionization parameter associated with strong, low-metallicity star formation may reduce the covering fraction or column density of neutral hydrogen, further easing Ly\u03b1 escape. The use of nebular emission line ratios may prove useful in the identification of galaxies with low opacity to Ly\u03b1 photons across a range of redshifts.",
"doi": "10.3847/0004-637X/830/1/52",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2016-10-10",
"series_number": "1",
"volume": "830",
"issue": "1",
"pages": "Art. No. 52"
},
{
"id": "authors:pkhb8-e1y26",
"collection": "authors",
"collection_id": "pkhb8-e1y26",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160912-091542652",
"type": "article",
"title": "The Connection Between Reddening, Gas Covering Fraction, and the Escape of Ionizing Radiation at High Redshift",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
}
],
"abstract": "Using a large sample of spectroscopically confirmed z ~ 3 galaxies, we establish an empirical relationship between reddening (E(B-V), neutral gas covering fraction (f_(cov)HI), and the escape of ionizing (Lyman continuum, LyC) photons. Our sample includes 933 galaxies at z ~ 3,121 of which have deep spectroscopic observations (\u22737 hr) at 850 \u227e \u03bb_(rest) \u227e 1300 \u00c5 with the Low Resolution Imaging Spectrograph on Keck. The high covering fraction of outflowing optically thick HI indicated by the composite pectra of these galaxies implies that photoelectric absorption, rather than dust attenuation, dominates the depletion of LyC photons. By modeling the composite spectra as the combination of an unattenuated stellar spectrum including nebular continuum emission with one that is absorbed by HI and reddened by a line-of-sight extinction, we derive an empirical relationship between E(B-V) and f_(cov) HI. Galaxies with redder UV continua have larger covering fractions of HI characterized by higher line-of-sight extinctions. We develop a model which connects the ionizing escape fraction with E(B-V), and which may be used to estimate the ionizing escape fraction for an ensemble of galaxies. Alternatively, direct measurements of the escape fraction for our sample allow us to constrain the intrinsic LyC-to-UV flux density ratio to be \u3008900 \u00c5)/S(1500 \u00c5\u3009_(int) \u2273 0.20, a value that favors stellar population models that include weaker stellar winds, a flatter initial mass function, and/or binary evolution. Last, we demonstrate how the framework discussed here may be used to assess the pathways by which ionizing radiation escapes from high-redshift galaxies.",
"doi": "10.3847/0004-637X/828/2/108",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2016-09-10",
"series_number": "2",
"volume": "828",
"issue": "2",
"pages": "Art. No. 108"
},
{
"id": "authors:ndgt1-ssz15",
"collection": "authors",
"collection_id": "ndgt1-ssz15",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160912-133213600",
"type": "article",
"title": "Spectroscopic Measurements of the Far-Ultraviolet Dust Attenuation Curve at z~3",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
}
],
"abstract": "We present the first spectroscopic measurements of the shape of the far-ultraviolet (far-UV; \u03bb = 950-1500 \u00c5) dust attenuation curve at high redshift (z ~ 3). Our analysis employs rest-frame UV spectra of 933 galaxies at z ~ 3, 121 of which have very deep spectroscopic observations (\u22737hr) at \u03bb = 850 - 1300 \u00c5, with the Low Resolution Imaging Spectrograph on the Keck Telescope. By using an iterative approach in which we calculate the ratios of composite spectra in different bins of continuum color excess, E(B-V), we derive a dust curve that implies a lower attenuation in the far-UV for a given E(B-V) than those obtained with standard attenuation curves. We demonstrate that the UV composite spectra of z ~ 3 galaxies can be modeled well by assuming our new attenuation curve, a high covering fraction of Hi, and absorption from the Lyman\u2013Werner bands of H_2 with a small (\u227e20%) covering fraction. The low covering fraction of H_2 relative to that of the H_I and dust suggests that most of the dust in the ISM of typical galaxies at z ~ 3 is unrelated to the catalysis of H_2, and is associated with other phases of the ISM (i.e., the ionized and neutral gas). The far-UV dust curve implies a factor of \u2248 2 lower dust attenuation of Lyman continuum (ionizing) photons relative to those inferred from the most commonly assumed attenuation curves for L^* galaxies at z ~ 3. Our results may be utilized to assess the degree to which ionizing photons are attenuated in H ii regions or, more generally, in the ionized or low column density N(HI) \u227e 10^(17.2) cm^(\u22122) neutral ISM of high-redshift galaxies.",
"doi": "10.3847/0004-637X/828/2/107",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2016-09-10",
"series_number": "2",
"volume": "828",
"issue": "2",
"pages": "Art. No. 107"
},
{
"id": "authors:bzybh-hg986",
"collection": "authors",
"collection_id": "bzybh-hg986",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-073437352",
"type": "article",
"title": "Herschel protocluster survey: a search for dusty star-forming galaxies in protoclusters at z = 2\u20133",
"author": [
{
"family_name": "Kato",
"given_name": "Y.",
"clpid": "Kato-Y"
},
{
"family_name": "Matsuda",
"given_name": "Y.",
"clpid": "Matsuda-Yuichi"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Swinbank",
"given_name": "A. M.",
"clpid": "Swinbank-A-M"
},
{
"family_name": "Hatsukade",
"given_name": "B.",
"clpid": "Hatsukade-B"
},
{
"family_name": "Umehata",
"given_name": "H.",
"clpid": "Umehata-Hideki"
},
{
"family_name": "Tanaka",
"given_name": "I.",
"clpid": "Tanaka-I"
},
{
"family_name": "Saito",
"given_name": "T.",
"clpid": "Saito-T"
},
{
"family_name": "Iono",
"given_name": "D.",
"orcid": "0000-0002-2364-0823",
"clpid": "Iono-Daisuke"
},
{
"family_name": "Tamura",
"given_name": "Y.",
"clpid": "Tamura-Yoichi"
},
{
"family_name": "Kohno",
"given_name": "K.",
"orcid": "0000-0002-4052-2394",
"clpid": "Kohno-Kotaro"
},
{
"family_name": "Erb",
"given_name": "D. K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Lehmer",
"given_name": "B. D.",
"orcid": "0000-0003-2192-3296",
"clpid": "Lehmer-B-D"
},
{
"family_name": "Geach",
"given_name": "J. E.",
"orcid": "0000-0003-4964-4635",
"clpid": "Geach-J-E"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Alexander",
"given_name": "D. M.",
"orcid": "0000-0002-5896-6313",
"clpid": "Alexander-D-M"
},
{
"family_name": "Yamada",
"given_name": "T.",
"clpid": "Yamada-Toru"
},
{
"family_name": "Hayashino",
"given_name": "T.",
"clpid": "Hayashino-T"
}
],
"abstract": "We present a Herschel/SPIRE survey of three protoclusters at z = 2 \u2212 3 (2QZCluster, HS1700, SSA22). Based on the SPIRE colours (S_(350)/S_(250) and S_(500)/S_(350)) of 250 \u03bcm sources, we selected high redshift dusty star-forming galaxies potentially associated with the protoclusters. In the 2QZCluster field, we found a 4\u03c3 overdensity of six SPIRE sources around 4.5\u2032 (\u223c 2.2 Mpc) from a density peak of H\u03b1 emitters at z = 2.2. In the HS1700 field, we found a 5\u03c3 overdensity of eight SPIRE sources around 2.1\u2032 (\u223c 1.0 Mpc) from a density peak of LBGs at z = 2.3. We did not find any significant overdensities in SSA22 field, but we found three 500 \u03bcm sources are concentrated 3\u2032 (\u223c1.4 Mpc) east to the LAEs overdensity. If all the SPIRE sources in these three overdensities are associated with protoclusters, the inferred star-formation rate densities are 10^3 \u2212 10^4 times higher than the average value at the same redshifts. This suggests that dusty star-formation activity could be very strongly enhanced in z \u223c 2 \u2212 3 protoclusters. Further observations are needed to confirm the redshifts of the SPIRE sources and to investigate what processes enhance the dusty star-formation activity in z \u223c 2 \u2212 3 protoclusters.",
"doi": "10.1093/mnras/stw1237",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2016-08-21",
"series_number": "4",
"volume": "460",
"issue": "4",
"pages": "3861-3872"
},
{
"id": "authors:wwx1c-get84",
"collection": "authors",
"collection_id": "wwx1c-get84",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161004-083721878",
"type": "article",
"title": "Reconciling the Stellar and Nebular Spectra of High-redshift Galaxies",
"author": [
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
}
],
"abstract": "We present a combined analysis of rest-frame far-UV (FUV; 1000\u20132000 \u00c5) and rest-frame optical (3600\u20137000 \u00c5) composite spectra formed from very deep Keck/LRIS and Keck/MOSFIRE observations of a sample of 30 star-forming galaxies with z = 2.40 \u00b1 0.11, selected to be broadly representative of the full KBSS-MOSFIRE spectroscopic survey. Since the same massive stars are responsible for the observed FUV continuum and for the excitation of the observed nebular emission, a self-consistent stellar population synthesis model should simultaneously match the details of the FUV stellar+nebular continuum and\u2014when inserted as the excitation source in photoionization models\u2014predict all observed nebular emission line ratios. We find that only models including massive star binaries, having low stellar metallicity (Z_*/Z_\u2299 \u2243 0.1) but relatively high nebular (ionized gas-phase) abundances Z_(neb)/Z_\u2299 \u2243 0.5), can successfully match all of the observational constraints. We show that this apparent discrepancy is naturally explained by highly super-solar O/Fe (\u22434-5(O/Fe_\u2299), expected for a gas whose enrichment is dominated by the products of core-collapse supernovae. While O dominates the physics of the ionized gas (and thus the nebular emission lines), Fe dominates the extreme-UV (EUV) and FUV opacity and controls the mass-loss rate from massive stars, resulting in particularly dramatic effects for massive stars in binary systems. This high nebular excitation\u2014caused by the hard EUV spectra of Fe-poor massive stars\u2014is much more common at high redshift (z \u2273 2) than low redshift due to systematic differences in the star formation history of typical galaxies.",
"doi": "10.3847/0004-637X/826/2/159",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2016-08-01",
"series_number": "2",
"volume": "826",
"issue": "2",
"pages": "Art. No. 159"
},
{
"id": "authors:j5d4c-w5z10",
"collection": "authors",
"collection_id": "j5d4c-w5z10",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160801-154642815",
"type": "article",
"title": "Q1549-C25: A Clean Source of Lyman-Continuum Emission at z = 3.15",
"author": [
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Siana",
"given_name": "Brian",
"orcid": "0000-0002-4935-9511",
"clpid": "Siana-Brian-D"
},
{
"family_name": "Mostardi",
"given_name": "Robin E.",
"clpid": "Mostardi-Robin-E"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
}
],
"abstract": "We present observations of Q1549-C25, an ~L^* star-forming galaxy at z = 3.15 for which Lyman-continuum (LyC) radiation is significantly detected in deep Keck/LRIS spectroscopy. We find no evidence of contamination from a lower-redshift interloper close to the line of sight in the high signal-to-noise spectrum of Q1549-C25. Furthermore, the morphology of Q1549-C25 in V 606, J 125, and H 160 Hubble Space Telescope (HST) imaging reveals that the object consists of a single, isolated component within 1\". In combination, these data indicate Q1549-C25 as a clean spectroscopic detection of LyC radiation, only the second such object discovered to date at z ~ 3. We model the spectral energy distribution of Q1549-C25, finding evidence of negligible dust extinction, an age (assuming continuous star formation) of ~1 Gyr, and a stellar mass of M_* =7.9 x 10^9,M_\u2609. Although it is not possible to derive strong constraints on the absolute escape fraction of LyC emission, f _(esc)(LyC), from a single object, we use simulations of intergalactic and circumgalactic absorption to infer f_(esc)(LyC)\u2a7e 0.51 at 95% confidence. The combination of deep Keck/LRIS spectroscopy and Hubble Space Telescope imaging is required to assemble a larger sample of objects like Q1549-C25, and obtain robust constraints on the average f _(esc)(LyC) at z ~ 3 and beyond.",
"doi": "10.3847/2041-8205/826/2/L24",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2016-08-01",
"series_number": "2",
"volume": "826",
"issue": "2",
"pages": "Art. No. L24"
},
{
"id": "authors:w5jz4-gq343",
"collection": "authors",
"collection_id": "w5jz4-gq343",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160707-102219945",
"type": "article",
"title": "Substructure within the SSA22 protocluster at z \u2248 3.09",
"author": [
{
"family_name": "Topping",
"given_name": "Michael W.",
"clpid": "Topping-M-W"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present the results of a densely sampled spectroscopic survey of the SSA22 protocluster at z \u2248 3.09. Our sample with Keck/LRIS spectroscopy includes 106 Ly\u03b1 emitters (LAEs) and 40 Lyman break galaxies (LBGs) at z = 3.05\u20133.12. These galaxies are contained within the 9' \u00d7 9' region in which the protocluster was discovered, which also hosts the maximum galaxy overdensity in the SSA22 region. The redshift histogram of our spectroscopic sample reveals two distinct peaks, at z = 3.069 (blue; 43 galaxies) and z = 3.095 (red; 103 galaxies). Furthermore, objects in the blue and red peaks are segregated on the sky, with galaxies in the blue peak concentrating toward the western half of the field. These results suggest that the blue and red redshift peaks represent two distinct structures in physical space. Although the double-peaked redshift histogram is traced in the same manner by LBGs and LAEs, and brighter and fainter galaxies, we find that 9 out of 10 X-ray AGNs in SSA22, and all 7 spectroscopically confirmed giant Ly\u03b1 \"blobs,\" reside in the red peak. We combine our data set with sparsely sampled spectroscopy from the literature over a significantly wider area, finding preliminary evidence that the double-peaked structure in redshift space extends beyond the region of our dense spectroscopic sampling. In order to fully characterize the three-dimensional structure, dynamics, and evolution of large-scale structure in the SSA22 overdensity, we require the measurement of large samples of LAE and LBG redshifts over a significantly wider area, as well as detailed comparisons with cosmological simulations of massive cluster formation.",
"doi": "10.3847/2041-8205/824/1/L11",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2016-06-10",
"series_number": "1",
"volume": "824",
"issue": "1",
"pages": "Art. No. L11"
},
{
"id": "authors:raavv-3gb41",
"collection": "authors",
"collection_id": "raavv-3gb41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160707-085528559",
"type": "article",
"title": "A Newly Forming Cold Flow Protogalactic Disk, a Signature of Cold Accretion from the Cosmic Web",
"author": [
{
"family_name": "Martin",
"given_name": "D. Christopher",
"orcid": "0000-0002-8650-1644",
"clpid": "Martin-D-Christopher"
},
{
"family_name": "Matuszewski",
"given_name": "Mateusz",
"clpid": "Matuszewski-M"
},
{
"family_name": "Morrissey",
"given_name": "Patrick",
"orcid": "0000-0001-8177-1023",
"clpid": "Morrissey-P"
},
{
"family_name": "Neill",
"given_name": "James D.",
"orcid": "0000-0002-0466-1119",
"clpid": "Neill-J-D"
},
{
"family_name": "Moore",
"given_name": "Anna",
"orcid": "0000-0002-2894-6936",
"clpid": "Moore-A-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
}
],
"abstract": "How galaxies form from, and are fueled by, gas from the intergalactic medium (IGM) remains one of the major unsolved problems in galaxy formation. While the classical Cold Dark Matter paradigm posits galaxies forming from cooling virialized gas, recent theory and numerical simulations have highlighted the importance of cold accretion flows\u2014relatively cool (T ~ few \u00d7 104 K) unshocked gas streaming along filaments into dark matter halos, including hot, massive, high-redshift halos. These flows are thought to deposit gas and angular momentum into the circumgalactic medium resulting in disk- or ring-like structures, eventually coalescing into galaxies forming at filamentary intersections. We earlier reported a bright, Ly\u03b1 emitting filament near the QSO HS1549+19 at redshift z = 2.843 discovered with the Palomar Cosmic Web Imager. We now report that the bright part of this filament is an enormous (R > 100 kpc) rotating structure of hydrogen gas with a disk-like velocity profile consistent with a 4 \u00d7 10^(12) M_\u2299 halo. The orbital time of the outer part of the what we term a \"protodisk\" is comparable to the virialization time and the age of the universe at this redshift. We propose that this protodisk can only have recently formed from cold gas flowing directly from the cosmic web.",
"doi": "10.3847/2041-8205/824/1/L5",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2016-06-10",
"series_number": "1",
"volume": "824",
"issue": "1",
"pages": "Art. No. L5"
},
{
"id": "authors:tz4vr-4q521",
"collection": "authors",
"collection_id": "tz4vr-4q521",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160106-084019133",
"type": "article",
"title": "A millimetre-wave redshift search for the unlensed HyLIRG, HS1700.850.1",
"author": [
{
"family_name": "Chapman",
"given_name": "S. C.",
"clpid": "Chapman-S-C"
},
{
"family_name": "Bertoldi",
"given_name": "F.",
"orcid": "0000-0002-1707-1775",
"clpid": "Bertoldi-F"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Blain",
"given_name": "A. W.",
"orcid": "0000-0001-7489-5167",
"clpid": "Blain-A-W"
},
{
"family_name": "Geach",
"given_name": "J. E.",
"orcid": "0000-0003-4964-4635",
"clpid": "Geach-J-E"
},
{
"family_name": "Gurwell",
"given_name": "M.",
"orcid": "0000-0003-0685-3621",
"clpid": "Gurwell-M-A"
},
{
"family_name": "Ivison",
"given_name": "R. J.",
"orcid": "0000-0001-5118-1313",
"clpid": "Ivison-R-J"
},
{
"family_name": "Petitpas",
"given_name": "G. R.",
"clpid": "Petitpas-G-R"
},
{
"family_name": "Reddy",
"given_name": "N.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
}
],
"abstract": "We report the redshift of an unlensed, highly obscured submillimetre galaxy (SMG), HS1700.850.1, the brightest SMG (S_(850\u2009\u03bcm) = 19.1 mJy) detected in the James Clerk Maxwell Telescope/Submillimetre Common-user Bolometer Array-2 (JCMT/SCUBA-2) Baryonic Structure Survey, based on the detection of its ^(12)CO line emission. Using the Institute Radio Astronomie Millimetrique Plateau de Bure Interferometer with 3.6 GHz band width, we serendipitously detect an emission line at 150.6 GHz. From a search over 14.5 GHz in the 3- and 2-mm atmospheric windows, we confirm the identification of this line as ^(12)CO(5\u20134) at z = 2.816, meaning that it does not reside in the z \u223c 2.30 proto-cluster in this field. Measurement of the 870 \u03bcm source size (<0.85 arcsec) from the Sub-Millimetre Array (SMA) confirms a compact emission in a S_(870\u2009\u03bcm) = 14.5 mJy, L_(IR) \u223c 10^(13) L\u2299 component, suggesting an Eddington-limited starburst. We use the double-peaked 12CO line profile measurements along with the SMA size constraints to study the gas dynamics of a HyLIRG, estimating the gas and dynamical masses of HS1700.850.1. While HS1700.850.1 is one of the most extreme galaxies known in the Universe, we find that it occupies a relative void in the Lyman-Break Galaxy distribution in this field. Comparison with other extreme objects at similar epochs (HyLIRG Quasars), and cosmological simulations, suggests such an anti-bias of bright SMGs could be relatively common, with the brightest SMGs rarely occupying the most overdense regions at z = 2\u20134.",
"doi": "10.1093/mnras/stv1618",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2015-10-11",
"series_number": "1",
"volume": "453",
"issue": "1",
"pages": "951-959"
},
{
"id": "authors:v68jb-mcw20",
"collection": "authors",
"collection_id": "v68jb-mcw20",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151027-125431249",
"type": "article",
"title": "A High-Resolution Hubble Space Telescope Study of Apparent Lyman Continuum Leakers at z~3",
"author": [
{
"family_name": "Mostardi",
"given_name": "R. E.",
"clpid": "Mostardi-R-E"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Trainor",
"given_name": "R. F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Reddy",
"given_name": "N. A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Siana",
"given_name": "B.",
"orcid": "0000-0002-4935-9511",
"clpid": "Siana-Brian-D"
}
],
"abstract": "We present U_(336)V_(606)J_(125)H_(160) follow-up Hubble Space Telescope (HST) observations of 16 z ~ 3 candidate Lyman continuum (LyC) emitters in the HS1549+1919 field. With these data, we obtain high spatial-resolution photometric redshifts of all sub-arcsecond components of the LyC candidates in order to eliminate foreground contamination and identify robust candidates for leaking LyC emission. Of the 16 candidates, we find one object with a robust LyC detection that is not due to foreground contamination. This object (MD5) resolves into two components; we refer to the LyC-emitting component as MD5b. MD5b has an observed 1500 \u00c5 to 900 \u00c5 flux-density ratio of (F_(UV)/F_(LyC)_(obs) = 4.0 \u00b1 2.0, compatible with predictions from stellar population synthesis models. Assuming minimal IGM absorption, this ratio corresponds to a relative (absolute) escape fraction of f_(esc,rel)^(MD5b) = 75%\u2013100% f_(esc,abs)^(MD5b) = 14%\u201319%). The stellar population fit to MD5b indicates an age of \u227e50 Myr, which is in the youngest 10% of the HST sample and the youngest third of typical z ~ 3 Lyman break galaxies, and may be a contributing factor to its LyC detection. We obtain a revised, contamination-free estimate for the comoving specific ionizing emissivity at z = 2.85, indicating (with large uncertainties) that star-forming galaxies provide roughly the same contribution as QSOs to the ionizing background at this redshift. Our results show that foreground contamination prevents ground-based LyC studies from obtaining a full understanding of LyC emission from z ~ 3 star-forming galaxies. Future progress in direct LyC searches is contingent upon the elimination of foreground contaminants through high spatial-resolution observations, and upon acquisition of sufficiently deep LyC imaging to probe ionizing radiation in high-redshift galaxies.",
"doi": "10.1088/0004-637X/810/2/107",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2015-09-10",
"series_number": "2",
"volume": "810",
"issue": "2",
"pages": "Art. No. 107"
},
{
"id": "authors:c1m4b-a5j47",
"collection": "authors",
"collection_id": "c1m4b-a5j47",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151020-100556005",
"type": "article",
"title": "The Spectroscopic Properties of Ly\u03b1-Emitters at z ~2.7: Escaping Gas and Photons from Faint Galaxies",
"author": [
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
}
],
"abstract": "We present a spectroscopic survey of 318 faint (R ~ 27, L ~ 0.1 L*), Ly\u03b1-emission-selected galaxies (LAEs) in regions centered on the positions of hyperluminous QSOs (HLQSOs) at 2.5 < z < 3. A sample of 32 LAEs with rest-frame optical emission line spectra from Keck/Multi-Object Spectrometer For InfraRed Exploration (MOSFIRE) are used to interpret the LAE spectra in the context of their systemic redshifts. The fields are part of the Keck Baryonic Structure Survey, which includes substantial ancillary multi-wavelength imaging from both the ground and space. From a quantitative analysis of the diverse Ly\u03b1 spectral morphologies, including line widths, asymmetries, and multi-peaked profiles, we find that peak widths and separations are typically smaller than among samples of more luminous continuum-selected galaxies (Lyman-break galaxies and their analogs; LBGs) at similar redshifts. We find tentative evidence for an association between Ly\u03b1 spectral morphology and external illumination by the nearby HLQSO. Using the MOSFIRE subsample, we find that the peak of the resolved (R \u2248 1300) Ly\u03b1 line is shifted by +200 km s^(\u22121) with respect to systemic across a diverse set of galaxies including both LAEs and LBGs. We also find a small number of objects with significantly blueshifted Ly\u03b1 emission, a potential indicator of accreting gas. The Ly\u03b1-to-H\u03b1 line ratios measured for the MOSFIRE subset suggest that the LAEs in this sample have Ly\u03b1 escape fractions f_(esc,Ly\u03b1) \u2248 30%, significantly higher than typical LBG samples. Using redshifts calibrated by our MOSFIRE sample, we construct composite LAE spectra, finding the first evidence for metal-enriched outflows in such intrinsically faint high-redshift galaxies. These outflows have smaller continuum covering fractions (f_c \u2248 0.3) and velocities (\u03bd_(ave) \u2248 100\u2013200 km s^(\u22121), \u03bd_(max) \u2248 500 km s^(\u22121)) than those associated with typical LBGs, suggesting that the gas covering fraction is a likely driver of the high Ly\u03b1 and Ly-continuum escape fractions of LAEs with respect to LBGs. Our results suggest a similar scaling of outflow velocity with star formation rate (SFR) as is observed at lower redshifts (\u03bd_(outflow) ~ SFR^(0.25)) and indicate that a substantial fraction of gas is ejected with \u03bd > \u03bd_(sec). Further observations, including deep spectroscopy in the observed near-IR, will further probe the evolution and enrichment of these galaxies in the context of their gaseous environments.",
"doi": "10.1088/0004-637X/809/1/89",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2015-08-10",
"series_number": "1",
"volume": "809",
"issue": "1",
"pages": "Art. No. 89"
},
{
"id": "authors:nc4dq-zkn31",
"collection": "authors",
"collection_id": "nc4dq-zkn31",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151002-150103207",
"type": "article",
"title": "Correlation between star formation activity and electron density of ionized gas at z = 2.5",
"author": [
{
"family_name": "Shimakawa",
"given_name": "Rhythm",
"clpid": "Shimakawa-Rhythm"
},
{
"family_name": "Kodama",
"given_name": "Tadayuki",
"clpid": "Kodama-Tadayuki"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Tadaki",
"given_name": "Ken-ichi",
"clpid": "Tadaki-Ken-ichi"
},
{
"family_name": "Tanaka",
"given_name": "Ichi",
"clpid": "Tanaka-Ichi"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Hayashi",
"given_name": "Masao",
"clpid": "Hayashi-Masao"
},
{
"family_name": "Koyama",
"given_name": "Yusei",
"clpid": "Koyama-Yusei"
},
{
"family_name": "Suzuki",
"given_name": "Tomoko L.",
"clpid": "Suzuki-Tomoko-L"
},
{
"family_name": "Yamamoto",
"given_name": "Moegi",
"clpid": "Yamamoto-Moegi"
}
],
"abstract": "In the redshift interval of 2 < z < 3, the physical conditions of the interstellar medium (ISM) in star-forming galaxies are likely to be different from those in the local Universe because of lower gaseous metallicities, higher gas fractions, and higher star formation activities. In fact, observations suggest that higher electron densities, higher ionization parameters, and harder UV radiation fields are common. In this paper, based on the spectra of H \u03b1-selected star-forming galaxies at z = 2.5 taken with Multi-Object Spectrometer for InfraRed Exploration on Keck-1 telescope, we measure electron densities (n_e) using the oxygen line ratio ([O\u2009II] \u03bb\u03bb3726,3729), and investigate the relationships between the electron density of ionized gas and other physical properties. As a result, we find that the specific star formation rate (sSFR) and the surface density of SFR (\u03a3_(SFR)) are correlated with the electron density at z = 2.5 for the first time. The \u03a3_(SFR)\u2013n_e relation is likely to be linked to the star formation law in H\u2009II regions (where star formation activity is regulated by interstellar pressure). Moreover, we discuss the mode of star formation in those galaxies. The correlation between sSFR and \u03a3_(SFR) suggests that highly star-forming galaxies (with high sSFR) tend to be characterized by higher surface densities of star formation (\u03a3_(SFR)) and thus higher n_e values as well.",
"doi": "10.1093/mnras/stv915",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2015-08-01",
"series_number": "2",
"volume": "451",
"issue": "2",
"pages": "1284-1289"
},
{
"id": "authors:05zv6-1fh11",
"collection": "authors",
"collection_id": "05zv6-1fh11",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160317-113846199",
"type": "article",
"title": "Physical Properties of a Pilot Sample of Spectroscopic Close Pair Galaxies at z ~ 2",
"author": [
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Checlair",
"given_name": "Jade",
"clpid": "Chaclair-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We use Hubble Space Telescope Wide-field Camera 3 rest-frame optical imaging to select a pilot sample of star-forming galaxies in the redshift range z = 2.00\u20132.65 whose multi-component morphologies are consistent with expectations for major mergers. We follow up this sample of major merger candidates with Keck/NIRSPEC long-slit spectroscopy obtained in excellent seeing conditions (FWHM ~0.5 arcsec) to obtain H\u03b1-based redshifts of each of the morphological components in order to distinguish spectroscopic pairs from false pairs created by projection along the line of sight. Of the six candidate pairs observed, companions (estimated mass ratios 5:1 and 7:1) are detected for two galaxies down to a 3\u03c3 limiting emission-line flux of ~ 10^(-17) erg s^(\u22121) cm^(\u22122). This detection rate is consistent with a ~50% false-pair fraction at such angular separations (1\u20132 arcsec) and with recent claims that the star formation rate (SFR) can differ by an order of magnitude between the components in such mergers. The two spectroscopic pairs identified have a total SFR, SFR surface densities, and stellar masses consistent on average with the overall z ~ 2 star-forming galaxy population.",
"doi": "10.1088/0004-637X/808/2/160",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2015-08",
"series_number": "2",
"volume": "808",
"issue": "2",
"pages": "Art. No. 60"
},
{
"id": "authors:csece-dhm83",
"collection": "authors",
"collection_id": "csece-dhm83",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141209-081520548",
"type": "article",
"title": "Detection of hot, metal-enriched outflowing gas around z \u2248 2.3 star-forming galaxies in the Keck Baryonic Structure Survey",
"author": [
{
"family_name": "Turner",
"given_name": "Monica L.",
"clpid": "Turner-M-L"
},
{
"family_name": "Schaye",
"given_name": "Joop",
"clpid": "Schaye-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
}
],
"abstract": "We use quasar absorption lines to study the physical conditions in the circumgalactic medium of redshift z \u2248 2.3 star-forming galaxies taken from the Keck Baryonic\nStructure Survey (KBSS). In Turner et al. (2014) we used the pixel optical depth technique to show that absorption by Hi and the metal ions OvI, Nv, CIv, CIII and SiIv is strongly enhanced within \u2502\u0394v\u2502\u227e. 170 km s^(-1) and projected distances \u2502d\u2502\u227e. 180 proper kpc from sightlines to the background quasars. Here we demonstrate that the OvI absorption is also strongly enhanced at fixed HI, CIv, and SiIv optical depths, and that this enhancement extends out to ~ 350 km s^(-1). At fixed HI the increase in the median OvI optical depth near galaxies is 0.3-0.7 dex and is detected at 2-3-\u03c3 confidence for all seven HI bins that have log_(10) T_(HI) \u2265 -1.5. We use ionisation models to show that the observed strength of OvI as a function of HI is consistent with enriched, photoionised gas for pixels with T_(HI) \u2273 10. However, for pixels with T_(HI) \u227e 1 this would lead to implausibly high metallicities at low densities if the gas were photoionised by the background radiation. This indicates that the galaxies are surrounded by gas that is sufficiently hot to be collisionally ionised (T > 10^5 K) and that a substantial fraction of the hot gas has a metallicity \u2273 10^(-1) of solar. Given the high metallicity and large velocity extent (out to ~ 1.5 x v_(circ)) of this gas, we conclude that we have detected hot, metal enriched outflows arising from star-forming\ngalaxies.",
"doi": "10.1093/mnras/stv750",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2015-06-21",
"series_number": "2",
"volume": "450",
"issue": "2",
"pages": "2067-2082"
},
{
"id": "authors:x5hcn-7jd37",
"collection": "authors",
"collection_id": "x5hcn-7jd37",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150619-095300192",
"type": "article",
"title": "Investigating H\u03b1, UV, and IR Star-formation Rate Diagnostics for a Large Sample of z ~ 2 Galaxies",
"author": [
{
"family_name": "Shivaei",
"given_name": "Irene",
"clpid": "Shivaei-Irene"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
}
],
"abstract": "We use a sample of 262 spectroscopically confirmed star-forming galaxies at redshifts 2.08 \u2264 z \u2264 2.51 to compare H\u03b1, ultraviolet (UV), and IR star formation rate (SFR) diagnostics and to investigate the dust properties of the galaxies. At these redshifts, the H\u03b1 line shifts to the K_s band. By comparing K_s-band photometry to underlying stellar population model fits to other UV, optical, and near-infrared data, we infer the H\u03b1 flux for each galaxy. We obtain the best agreement between H\u03b1- and UV-based SFRs if we assume that the ionized gas and stellar continuum are reddened by the same value and that the Calzetti attenuation curve is applied to both. Aided with MIPS 24 \u03bcm data, we find that an attenuation curve steeper than the Calzetti curve is needed to reproduce the observed IR/UV ratios of galaxies younger than 100 Myr. Furthermore, using the bolometric SFR inferred from the UV and mid-IR data (SFR_(IR)+SFR_(UV), we calculated the conversion between the H\u03b1 luminosity and SFR to be (7.5 \u00b1 1.3) x 10^(-42) for a Salpeter initial mass function, which is consistent with the Kennicutt conversion. The derived conversion factor is independent of any assumption of the dust correction and is robust to stellar population model uncertainties.",
"doi": "10.1088/0004-637X/804/2/149",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2015-05-10",
"series_number": "2",
"volume": "804",
"issue": "2",
"pages": "Art. No. 149"
},
{
"id": "authors:97yhd-e6s75",
"collection": "authors",
"collection_id": "97yhd-e6s75",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150518-101259875",
"type": "article",
"title": "A blind CO detection of a distant red galaxy in the HS1700+64 protocluster",
"author": [
{
"family_name": "Chapman",
"given_name": "S. C.",
"clpid": "Chapman-S-C"
},
{
"family_name": "Bertoldi",
"given_name": "F.",
"orcid": "0000-0002-1707-1775",
"clpid": "Bertoldi-F"
},
{
"family_name": "Smail",
"given_name": "Ian",
"orcid": "0000-0003-3037-257X",
"clpid": "Smail-Ian-R"
},
{
"family_name": "Blain",
"given_name": "A. W.",
"orcid": "0000-0001-7489-5167",
"clpid": "Blain-A-W"
},
{
"family_name": "Geach",
"given_name": "J. E.",
"orcid": "0000-0003-4964-4635",
"clpid": "Geach-J-E"
},
{
"family_name": "Gurwell",
"given_name": "M.",
"orcid": "0000-0003-0685-3621",
"clpid": "Gurwell-M-A"
},
{
"family_name": "Ivison",
"given_name": "R. J.",
"orcid": "0000-0001-5118-1313",
"clpid": "Ivison-R-J"
},
{
"family_name": "Petitpas",
"given_name": "G. R.",
"clpid": "Petitpas-G-R"
},
{
"family_name": "Reddy",
"given_name": "N.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We report the blind detection of ^(12)CO emission from a distant red galaxy, HS1700.DRG55. We have used the IRAM Plateau de Bure Interferometer WideX, with its 3.6 GHz of instantaneous dual-polarization bandwidth, to target ^(12)CO(3\u20132) from galaxies lying in the protocluster at z = 2.300 in the field HS1700+64. If indeed this line in DRG55 is ^(12)CO(3\u20132), its detection at 104.9 GHz indicates zCO = 2.296. None of the other eight known z \u223c 2.30 protocluster galaxies lying within the primary beam (PB) are detected in ^(12)CO, although the limits are \u223c2 \u00d7 worse towards the edge of the PB where several lie. The optical/near-IR magnitudes of DRG55 (R_AB > 27, KAB = 22.3) mean that optical spectroscopic redshifts are difficult with 10-m-class telescopes, but near-IR redshifts would be feasible. The 24-\u03bcm-implied star formation rate (210\u2009M_\u2299\u2009yr^\u22121), stellar mass (\u223c10^11\u2009M_\u2299) and ^(12)CO line luminosity (3.6 \u00d7 10^10\u2009K\u2009km\u2009s^\u22121\u2009 pc^2) are comparable to other normal ^(12)CO-detected star-forming galaxies in the literature, although the galaxy is some \u223c2 mag (\u223c6 \u00d7) fainter in the rest-frame UV than ^(12)CO-detected galaxies at z > 2. The detection of DRG55 in ^(12)CO complements three other ^(12)CO detected UV-bright galaxies in this protocluster from previous studies, and suggests that many optically faint galaxies in the protocluster may host substantial molecular gas reservoirs, and a full blind census of ^(12)CO in this overdense environment is warranted.",
"doi": "10.1093/mnrasl/slv010",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2015-05-01",
"series_number": "1",
"volume": "449",
"issue": "1",
"pages": "L68-L72"
},
{
"id": "authors:bdv16-5nt36",
"collection": "authors",
"collection_id": "bdv16-5nt36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150311-182729941",
"type": "article",
"title": "A Deep Hubble Space Telescope and Keck Search for Definitive Identification of Lyman Continuum Emitters at z ~ 3.1",
"author": [
{
"family_name": "Siana",
"given_name": "Brian",
"orcid": "0000-0002-4935-9511",
"clpid": "Siana-Brian-D"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Kulas",
"given_name": "Kristin R.",
"clpid": "Kulas-K-R"
},
{
"family_name": "Nestor",
"given_name": "Daniel B.",
"clpid": "Nestor-D-B"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Teplitz",
"given_name": "Harry I.",
"orcid": "0000-0002-7064-5424",
"clpid": "Teplitz-H-I"
},
{
"family_name": "Alavi",
"given_name": "Anahita",
"orcid": "0000-0002-8630-6435",
"clpid": "Alavi-A"
},
{
"family_name": "Brown",
"given_name": "Thomas M.",
"orcid": "0000-0002-1793-9968",
"clpid": "Brown-T-M"
},
{
"family_name": "Conselice",
"given_name": "Christopher J.",
"orcid": "0000-0003-1949-7638",
"clpid": "Conselice-C-J"
},
{
"family_name": "Ferguson",
"given_name": "Henry C.",
"orcid": "0000-0001-7113-2738",
"clpid": "Ferguson-H-C"
},
{
"family_name": "Dickinson",
"given_name": "Mark",
"orcid": "0000-0001-5414-5131",
"clpid": "Dickinson-Mark-E"
},
{
"family_name": "Giavalisco",
"given_name": "Mauro",
"orcid": "0000-0002-7831-8751",
"clpid": "Giavalisco-M"
},
{
"family_name": "Colbert",
"given_name": "James W.",
"clpid": "Colbert-J-W"
},
{
"family_name": "Bridge",
"given_name": "Carrie R.",
"clpid": "Bridge-C-R"
},
{
"family_name": "Gardner",
"given_name": "Jonathan P.",
"clpid": "Gardner-J-P"
},
{
"family_name": "de Mello",
"given_name": "Duilia F.",
"clpid": "de-Mello-D-F"
}
],
"abstract": "Narrowband imaging of the rest-frame Lyman continuum (LyC) of galaxies at z ~ 3.1 has produced a large number of candidate LyC-emitting galaxies. These samples are contaminated by galaxies at lower redshift. To better understand LyC escape, we need an uncontaminated sample of galaxies that emit strongly in the LyC. Here we present deep Hubble Space Telescope imaging of five bright galaxies at z ~ 3.1 that had previously been identified as candidate LyC emitters with ground-based images. The WFC3 F336W images probe the LyC of galaxies at z > 3.06 and provide an order-of-magnitude increase in spatial resolution over ground-based imaging. The non-ionizing UV images often show multiple galaxies (or components) within ~ 1\" of the candidate LyC emission seen from the ground. In each case, only one of the components is emitting light in the F336W filter, which would indicate LyC escape if that component is at z > 3.06. We use Keck/NIRSPEC near-IR spectroscopy to measure redshifts of these components to distinguish LyC emitters from foreground contamination. We find that two candidates are low-redshift contaminants, one candidate had a previously misidentified redshift, and the other two cannot be confirmed as LyC emitters. The level of contamination is consistent with previous estimates. For the galaxies with z > 3.06, we derive strong l\u03c3 limits on the relative escape fraction between 0.07 and 0.09. We still do not have a sample of definitive LyC emitters, and a much larger study of low-luminosity galaxies is required. The combination of high-resolution imaging and deep spectroscopy is critical for distinguishing LyC emitters from foreground contaminants.",
"doi": "10.1088/0004-637X/804/1/17",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2015-05-01",
"series_number": "1",
"volume": "804",
"issue": "1",
"pages": "Art. No. 17"
},
{
"id": "authors:csrxc-h7d62",
"collection": "authors",
"collection_id": "csrxc-h7d62",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-150453949",
"type": "article",
"title": "Metal-line absorption around z \u2248 2.4 star-forming galaxies in the Keck Baryonic Structure Survey",
"author": [
{
"family_name": "Turner",
"given_name": "Monica L.",
"clpid": "Turner-M-L"
},
{
"family_name": "Schaye",
"given_name": "Joop",
"clpid": "Schaye-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
}
],
"abstract": "We study metal absorption around 854 z \u2248 2.4 star-forming galaxies taken from the Keck Baryonic Structure Survey. The galaxies examined in this work lie in the fields of 15 hyperluminous background quasi-stellar objects, with galaxy impact parameters ranging from 35 proper kpc (pkpc) to 2 proper Mpc (pMpc). Using the pixel optical depth technique, we present the first galaxy-centred 2D maps of the median absorption by O\u2009VI, N\u2009V, C\u2009IV, C\u2009III, and Si\u2009IV, as well as updated results for H\u2009I. At small galactocentric radii we detect a strong enhancement of the absorption relative to randomly located regions that extend out to at least 180 pkpc in the transverse direction, and \u00b1240 km\u2009s^(\u22121) along the line of sight (LOS, \u223c1\u2009pMpc in the case of pure Hubble flow) for all ions except N\u2009V. For C\u2009IV (and H\u2009I) we detect a significant enhancement of the absorption signal out to 2\u2009pMpc in the transverse direction, corresponding to the maximum impact parameter in our sample. After normalizing the median absorption profiles to account for variations in line strengths and detection limits, in the transverse direction we find no evidence for a sharp drop-off in metals distinct from that of H\u2009I. We argue instead that non-detection of some metal-line species in the extended circumgalactic medium is consistent with differences in the detection sensitivity. Along the LOS, the normalized profiles reveal that the enhancement in the absorption is more extended for O\u2009VI, C\u2009IV, and Si\u2009IV than for H\u2009I. We also present measurements of the scatter in the pixel optical depths, covering fractions, and equivalent widths as a function of projected galaxy distance. Limiting the sample to the 340 galaxies with redshifts measured from nebular emission lines does not decrease the extent of the enhancement along the LOS compared to that in the transverse direction. This rules out redshift errors as the source of the observed redshift-space anisotropy and thus implies that we have detected the signature of gas peculiar velocities from infall, outflows, or virial motions for H\u2009I, O\u2009VI, C\u2009IV, C\u2009III, and Si\u2009IV.",
"doi": "10.1093/mnras/stu1801",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2014-11-21",
"series_number": "1",
"volume": "445",
"issue": "1",
"pages": "794-822"
},
{
"id": "authors:5mkzm-qj837",
"collection": "authors",
"collection_id": "5mkzm-qj837",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140610-153701276",
"type": "article",
"title": "Strong Nebular Line Ratios in the Spectra of z ~ 2-3 Star Forming Galaxies: First Results from KBSS-MOSFIRE",
"author": [
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Turner",
"given_name": "Monica L.",
"clpid": "Turner-M-L"
},
{
"family_name": "Konidaris",
"given_name": "Nicholas P.",
"orcid": "0000-0003-1905-2815",
"clpid": "Konidaris-N-P"
},
{
"family_name": "Kulas",
"given_name": "Kristin R.",
"clpid": "Kulas-K-R"
},
{
"family_name": "Mace",
"given_name": "Gregory N.",
"orcid": "0000-0001-7875-6391",
"clpid": "Mace-G-N"
},
{
"family_name": "Matthews",
"given_name": "Keith",
"clpid": "Matthews-Keith-Astronomy"
},
{
"family_name": "McLean",
"given_name": "Ian S.",
"clpid": "McLean-I-S"
}
],
"abstract": "We present initial results of a deep near-IR spectroscopic survey covering the 15 fields of the Keck Baryonic Structure Survey using the recently commissioned MOSFIRE spectrometer on the Keck 1 telescope. We focus on a sample of 251 galaxies with redshifts 2.0 < z < 2.6, star formation rates (SFRs) 2 \u227e SFR \u227e 200 M_\u2609 yr^(\u20131), and stellar masses 8.6 < log (M_*/M_\u2609) < 11.4, with high-quality spectra in both H- and K-band atmospheric windows. We show unambiguously that the locus of z ~ 2.3 galaxies in the \"BPT\" nebular diagnostic diagram exhibits an almost entirely disjointed, yet similarly tight, relationship between the line ratios [N II] \u03bb6585/H\u03b1 and [O III]/H\u03b2 as compared to local galaxies. Using photoionization models, we argue that the offset of the z ~ 2.3 BPT locus relative to that at z ~ 0 is caused by a combination of harder stellar ionizing radiation field, higher ionization parameter, and higher N/O at a given O/H compared to most local galaxies, and that the position of a galaxy along the z ~ 2.3 star-forming BPT locus is surprisingly insensitive to gas-phase oxygen abundance. The observed nebular emission line ratios are most easily reproduced by models in which the net stellar ionizing radiation field resembles a blackbody with effective temperature T_(eff) = 50, 000-60, 000 K, the gas-phase oxygen abundances lie in the range 0.2 < Z/Z_\u2609 < 1.0, and the ratio of gas-phase N/O is close to the solar value. We critically assess the applicability at high redshift of commonly used strong line indices for estimating gas-phase metallicity, and consider the implications of the small intrinsic scatter of the empirical relationship between excitation-sensitive line indices and M_* (i.e., the \"mass-metallicity\" relation) at z \u2243 2.3.",
"doi": "10.1088/0004-637X/795/2/165",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2014-11-10",
"series_number": "2",
"volume": "795",
"issue": "2",
"pages": "Art. No. 165"
},
{
"id": "authors:7fnq2-n6y28",
"collection": "authors",
"collection_id": "7fnq2-n6y28",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141201-093722795",
"type": "article",
"title": "The Ly\u03b1 Properties of Faint Galaxies at z ~ 2-3 with Systemic Redshifts and Velocity Dispersions from Keck-MOSFIRE",
"author": [
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Nestor",
"given_name": "Daniel B.",
"clpid": "Nestor-D-B"
},
{
"family_name": "Kulas",
"given_name": "Kristin R.",
"clpid": "Kulas-K-R"
},
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Strom",
"given_name": "Allison L.",
"orcid": "0000-0001-6369-1636",
"clpid": "Strom-A-L"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Konidaris",
"given_name": "Nicholas P.",
"orcid": "0000-0003-1905-2815",
"clpid": "Konidaris-N-P"
},
{
"family_name": "Mace",
"given_name": "Gregory",
"orcid": "0000-0001-7875-6391",
"clpid": "Mace-G-N"
},
{
"family_name": "Matthews",
"given_name": "Keith",
"clpid": "Matthews-Keith-Astronomy"
},
{
"family_name": "McLean",
"given_name": "Ian S.",
"clpid": "McLean-I-S"
}
],
"abstract": "We study the Ly\u03b1 profiles of 36 spectroscopically detected Ly\u03b1-emitters (LAEs) at z ~ 2-3, using Keck MOSFIRE to measure systemic redshifts and velocity dispersions from rest-frame optical nebular emission lines. The sample has a median optical magnitude R = 26.0, and ranges from R \u2243 23 to R > 27, corresponding to rest-frame UV absolute magnitudes M _(UV) \u2243 \u201322 to M ^(UV) > \u201318.2. Dynamical masses range from M_(dyn) < 1.3 \u00d7 10^8 M_\u2609 to M_(dyn) = 6.8 \u00d7 10^9 M_\u2609, with a median value of M_(dyn) = 6.3 \u00d7 10^8 M_\u2609. Thirty of the 36 Ly\u03b1 emission lines are redshifted with respect to the systemic velocity with at least 1\u03c3 significance, and the velocity offset with respect to systemic \u0394v_(Ly\u03b1) is correlated with the R-band magnitude, M_(UV), and the velocity dispersion measured from nebular emission lines with >3\u03c3 significance: brighter galaxies with larger velocity dispersions tend to have larger values of \u0394v Ly\u03b1. We also make use of a comparison sample of 122 UV-color-selected R < 25.5 galaxies at z ~ 2, all with Ly\u03b1 emission and systemic redshifts measured from nebular emission lines. Using the combined LAE and comparison samples for a total of 158 individual galaxies, we find that \u0394v_(Ly\u03b1) is anti-correlated with the Ly\u03b1 equivalent width with 7\u03c3 significance. Our results are consistent with a scenario in which the Ly\u03b1 profile is determined primarily by the properties of the gas near the systemic redshift; in such a scenario, the opacity to Ly\u03b1 photons in lower mass galaxies may be reduced if large gaseous disks have not yet developed and if the gas is ionized by the harder spectrum of young, low metallicity stars.",
"doi": "10.1088/0004-637X/795/1/33",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2014-11-01",
"series_number": "1",
"volume": "795",
"issue": "1",
"pages": "Art. No. 33"
},
{
"id": "authors:bdwkr-1zy75",
"collection": "authors",
"collection_id": "bdwkr-1zy75",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140303-152428640",
"type": "article",
"title": "Intergalactic Medium Emission Observations with the Cosmic Web Imager. I. The Circum-QSO Medium of QSO 1549+19, and Evidence for a Filamentary Gas Inflow",
"author": [
{
"family_name": "Martin",
"given_name": "D. Christopher",
"orcid": "0000-0002-8650-1644",
"clpid": "Martin-D-Christopher"
},
{
"family_name": "Chang",
"given_name": "Daphne",
"clpid": "Chang-Daphne"
},
{
"family_name": "Matuszewski",
"given_name": "Matt",
"clpid": "Matuszewski-M"
},
{
"family_name": "Morrissey",
"given_name": "Patrick",
"orcid": "0000-0001-8177-1023",
"clpid": "Morrissey-P"
},
{
"family_name": "Rahman",
"given_name": "Shahin",
"clpid": "Rahman-S"
},
{
"family_name": "Moore",
"given_name": "Anna",
"clpid": "Moore-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "The Palomar Cosmic Web Imager (PCWI), an integral field spectrograph designed to detect and map low surface brightness emission, has obtained imaging spectroscopic maps of Ly\u03b1 from the circum-QSO medium (CQM) of QSO HS1549+19 at redshift z=2.843. Extensive extended emission is detected from the CQM, consistent with fluorescent and pumped Ly\u03b1 produced by the ionizing and Ly\u03b1 continuum of the QSO. Many features present in PCWI spectral images match those detected in narrow-band images. Filamentary structures with narrow line profiles are detected in several cases as long as 250-400 kpc. One of these is centered at a velocity redshifted with respect to the systemic velocity, and displays a spatially collimated and\nkinematically cold line profile increasing in velocity width approaching the QSO. This suggests that the filament gas is infalling onto the QSO, perhaps in a cold accretion flow. Because of the strong ionizing flux, the neutral column density is low, typically N(HI) ~ 10^(12)\u221210^(15) cm^(\u22122), and the line center optical depth is also low (typically \u03c4_0 <10), insufficient to display well-separated\ndouble peak emission characteristic of higher line optical depths. With a simple ionization and cloud model we can very roughly estimate the total gas mass (log M_(gas) = 12.5 \u00b1 0.5) and the total (log M_(tot) = 13.3\u00b1 0.5). We can also calculate a kinematic mass from the total line profile (2\u00d710^(13)M_\u2609), which agrees with the mass estimated from the gas emission. The intensity-binned\nspectrum of the CQM shows a progression in kinematic properties consistent with heirarchical structure formation.",
"doi": "10.1088/0004-637X/786/2/106",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2014-05-10",
"series_number": "2",
"volume": "768",
"issue": "2",
"pages": "Art. No. 106"
},
{
"id": "authors:mtwgn-gkm57",
"collection": "authors",
"collection_id": "mtwgn-gkm57",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140303-145821259",
"type": "article",
"title": "Intergalactic Medium Emission Observations with the Cosmic Web Imager. II. Discovery of Extended, Kinematically-Linked Emission around SSA22 Ly\u03b1 Blob 2",
"author": [
{
"family_name": "Martin",
"given_name": "D. Christopher",
"orcid": "0000-0002-8650-1644",
"clpid": "Martin-D-Christopher"
},
{
"family_name": "Chang",
"given_name": "Daphne",
"clpid": "Chang-Daphne"
},
{
"family_name": "Matuszewski",
"given_name": "Matt",
"clpid": "Matuszewski-M"
},
{
"family_name": "Morrissey",
"given_name": "Patrick",
"orcid": "0000-0001-8177-1023",
"clpid": "Morrissey-P"
},
{
"family_name": "Rahman",
"given_name": "Shahin",
"clpid": "Rahman-S"
},
{
"family_name": "Moore",
"given_name": "Anna",
"orcid": "0000-0002-2894-6936",
"clpid": "Moore-A-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Matsuda",
"given_name": "Yuichi",
"clpid": "Matsuda-Yuichi"
}
],
"abstract": "The intergalactic medium (IGM) is the dominant reservoir of baryons, delineates the large scale structure of the universe at low to moderate overdensities, and provides gas from which galaxies form and evolve. Simulations of a Cold Dark Matter (CDM) dominated universe predict that the\nIGM is distributed in a cosmic web of filaments, and that galaxies should form along and at the intersections of these filaments (Bond, Kofman, & Pogosyan 1994; Miralda-Escude et al. 1996). While observations of QSO absorption lines and the large-scale distribution of galaxies have\nconfirmed the CDM paradigm, the cosmic web of IGM has never been confirmed by direct imaging. Here we report our observation of the Ly\u03b1 blob-2 (LAB2) in SSA22, with the Cosmic Web Imager. This is an integral field spectrograph optimized for low surface brightness, extended emission. With 22 hours of total on- and off-source exposure, CWI has revealed that LAB2 has extended Ly\u03b1 emission which is organized into azimuthal zones consistent with filaments. We perform numerous tests with simulations and the data to secure the robustness of this result, which relies on data with modest signal-to-noise ratio. We have developed a\nsmoothing algorithm that permits visualization of data cube slices along image or spectral-image planes. With both raw and smoothed data cubes we demonstrate that the filaments are kinematically associated with LAB2 and display double-peaked profiles characteristic of optically thick Ly\u03b1 emission. The flux is 10-20 times brighter than expected for the average emission from the IGM but is consistent with boosted fluorescence from a buried QSO or gravitation cooling radiation. Using simple emission models we infer a baryon mass in the filaments of at least 1\u22124 \u00d7 10^(11)M_\u2609, and the dark halo mass is at least 2 \u00d7 10^(12)M_\u2609. The spatial-kinematic morphology is more consistent with inflow from the cosmic web than outflow from LAB2, although an outflow feature maybe present at one azimuth. LAB2 and the surrounding gas have significant and coaligned angular momentum, strengthening the case for their association.",
"doi": "10.1088/0004-637X/786/2/107",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2014-05-10",
"series_number": "2",
"volume": "786",
"issue": "2",
"pages": "Art. No. 107"
},
{
"id": "authors:8qq9j-2r382",
"collection": "authors",
"collection_id": "8qq9j-2r382",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140530-134610304",
"type": "article",
"title": "Testing metallicity indicators at z \u223c 1.4 with the gravitationally lensed galaxy CASSOWARY 20",
"author": [
{
"family_name": "James",
"given_name": "Bethan L.",
"clpid": "James-B-L"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Christensen",
"given_name": "Lise",
"clpid": "Christensen-L"
},
{
"family_name": "Auger",
"given_name": "Matthew W.",
"clpid": "Auger-M-W"
},
{
"family_name": "Becker",
"given_name": "George D.",
"clpid": "Becker-G-D"
},
{
"family_name": "King",
"given_name": "Lindsay J.",
"clpid": "King-L-J"
},
{
"family_name": "Quider",
"given_name": "Anna M.",
"clpid": "Quider-A-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present X-shooter observations of CASSOWARY 20 (CSWA 20), a star-forming (SFR \u223c 6 M_\u2299 yr^(\u22121)) galaxy at z = 1.433, magnified by a factor of 11.5 by the gravitational lensing produced by a massive foreground galaxy at z = 0.741. We analysed the integrated physical properties of the H\u2009ii regions of CSWA 20 using temperature- and density-sensitive emission lines. We find the abundance of oxygen to be \u223c1/7 of solar, while carbon is \u223c50 times less abundant than in the Sun. The unusually low C/O ratio may be an indication of a particularly rapid time-scale of chemical enrichment. The wide wavelength coverage of X-shooter gives us access to five different methods for determining the metallicity of CSWA 20, three based on emission lines from H\u2009ii regions and two on absorption features formed in the atmospheres of massive stars. All five estimates are in agreement, within the factor of \u223c2 uncertainty of each method. The interstellar medium (ISM) of CSWA 20 only partially covers the star-forming region as viewed from our direction; in particular, absorption lines from neutrals and first ions are exceptionally weak. We find evidence for large-scale outflows of the ISM with speeds of up 750\u2009km\u2009s^(\u22121), similar to the values measured in other high-z galaxies sustaining much higher rates of star formation.",
"doi": "10.1093/mnras/stu287",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2014-03-27",
"series_number": "2",
"volume": "440",
"issue": "2",
"pages": "1794-1809"
},
{
"id": "authors:rjxr9-e5x90",
"collection": "authors",
"collection_id": "rjxr9-e5x90",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140207-112247242",
"type": "article",
"title": "Precision Measures of the Primordial Abundance of Deuterium",
"author": [
{
"family_name": "Cooke",
"given_name": "Ryan J.",
"orcid": "0000-0001-7653-5827",
"clpid": "Cooke-R-J"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Jorgenson",
"given_name": "Regina A.",
"clpid": "Jorgenson-R-A"
},
{
"family_name": "Murphy",
"given_name": "Michael T.",
"clpid": "Murphy-M-T"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We report the discovery of deuterium absorption in the very metal-poor ([Fe/H] = \u20132.88) damped Ly\u03b1 system at z_abs = 3.06726 toward the QSO SDSS J1358+6522. On the basis of 13 resolved D I absorption lines and the damping wings of the H I Ly\u03b1 transition, we have obtained a new, precise measure of the primordial abundance of deuterium. Furthermore, to bolster the present statistics of precision D/H measures, we have reanalyzed all of the known deuterium absorption-line systems that satisfy a set of strict criteria. We have adopted a blind analysis strategy (to remove human bias) and developed a software package that is specifically designed for precision D/H abundance measurements. For this reanalyzed sample of systems, we obtain a weighted mean of (D/H)_p = (2.53 \u00b1 0.04) \u00d7 10^\u20135, corresponding to a universal baryon density 100 \u03a9_b, 0 h^2 = 2.202 \u00b1 0.046 for the standard model of big bang nucleosynthesis (BBN). By combining our measure of (D/H)p with observations of the cosmic microwave background (CMB), we derive the effective number of light fermion species, N eff = 3.28 \u00b1 0.28. We therefore rule out the existence of an additional (sterile) neutrino (i.e., N_eff = 4.046) at 99.3% confidence (2.7\u03c3), provided that the values of N eff and of the baryon-to-photon ratio (\u03b7_10) did not change between BBN and recombination. We also place a strong bound on the neutrino degeneracy parameter, independent of the 4He primordial mass fraction, Y P: \u03beD = +0.05 \u00b1 0.13 based only on the CMB+(D/H)_p observations. Combining this value of \u03beD with the current best literature measure of Y P, we find a 2\u03c3 upper bound on the neutrino degeneracy parameter, |\u03be| \u2264 +0.062.",
"doi": "10.1088/0004-637X/781/1/31",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2014-01-20",
"series_number": "1",
"volume": "781",
"issue": "1",
"pages": "Art. No. 31"
},
{
"id": "authors:r2crt-zvb06",
"collection": "authors",
"collection_id": "r2crt-zvb06",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140117-143100184",
"type": "article",
"title": "Narrowband Lyman-continuum Imaging of Galaxies at z ~ 2.85",
"author": [
{
"family_name": "Mostardi",
"given_name": "R. E.",
"clpid": "Mostardi-R-E"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Nestor",
"given_name": "D. B.",
"clpid": "Nestor-D-B"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "N. A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Trainor",
"given_name": "R. F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
}
],
"abstract": "We present results from a survey for z ~ 2.85 Lyman-continuum (LyC) emission in the HS1549+1933 field and place constraints on the amount of ionizing radiation escaping from star-forming galaxies. Using a custom narrowband filter (NB3420) tuned to wavelengths just below the Lyman limit at z \u2265 2.82, we probe the LyC spectral region of 49 Lyman break galaxies (LBGs) and 91 Ly\u03b1 emitters (LAEs) spectroscopically confirmed at z \u2265 2.82. Four LBGs and seven LAEs are detected in NB3420. Using V-band data probing the rest-frame nonionizing UV, we observe that many NB3420-detected galaxies exhibit spatial offsets between their LyC and nonionizing UV emission and are characterized by extremely blue NB3420\u2013V colors, corresponding to low ratios of nonionizing to ionizing radiation (F_(UV)/F_(LyC)) that are in tension with current stellar population synthesis models. We measure average values of (F_(UV)/F_(LyC)) for our LBG and LAE samples, correcting for foreground galaxy contamination and H I absorption in the intergalactic medium. We find (F_(UV)/F_(LyC)_(corr)^(LBG)= 82 \u00b1 45 and (F_(UV)/F_(LyC)_(corr)^(LAE)= 7.4 \u00b1 3.6. These flux density ratios correspond, respectively, to relative LyC escape fractions of f_(esc,rel)^(LBG) = 5%-8% and f_(esc,rel)^(LAE)=18%-49%, absolute LyC escape fractions of f_(esc)^(LBG)=1%-2% and f_(esc)^(LAE)=5%-15%, and a comoving LyC emissivity from star-forming galaxies of 8.8-15.0 \u00d7 10^(24) erg s^(\u20131) Hz^(\u20131) Mpc^(\u20133). In order to study the differential properties of galaxies with and without LyC detections, we analyze narrowband Ly\u03b1 imaging and rest-frame near-infrared imaging, finding that while LAEs with LyC detections have lower Ly\u03b1 equivalent widths on average, there is no substantial difference in the rest-frame near-infrared colors of LBGs or LAEs with and without LyC detections. These preliminary results are consistent with an orientation-dependent model where LyC emission escapes through cleared paths in a patchy interstellar medium.",
"doi": "10.1088/0004-637X/779/1/65",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2013-12-10",
"series_number": "1",
"volume": "779",
"issue": "1",
"pages": "Art. No. 65"
},
{
"id": "authors:a1sr0-bnm69",
"collection": "authors",
"collection_id": "a1sr0-bnm69",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131017-133655029",
"type": "article",
"title": "Constraints on Hyperluminous QSO Lifetimes via Fluorescent Ly\u03b1 Emitters at Z \u2243 2.7",
"author": [
{
"family_name": "Trainor",
"given_name": "Ryan",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present observations of a population of Ly\u03b1 emitters (LAEs) exhibiting fluorescent emission via the reprocessing of ionizing radiation from nearby hyperluminous QSOs. These LAEs are part of a survey at redshifts 2.5 < z < 2.9 combining narrow-band photometric selection and spectroscopic follow-up to characterize the emission mechanisms, physical properties, and three-dimensional locations of the emitters with respect to their nearby hyperluminous QSOs. These data allow us to probe the radiation field, and thus the radiative history, of the QSOs, and we determine that most of the eight QSOs in our sample have been active and of comparable luminosity for a time 1 Myr \u2272 t_Q \u2272 20 Myr. Furthermore, we find that the ionizing QSO emission must have an opening angle \u03b8 ~ 30\u00b0 or larger relative to the line of sight.",
"doi": "10.1088/2041-8205/775/1/L3",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2013-09-20",
"series_number": "1",
"volume": "775",
"issue": "1",
"pages": "Art. No. L3"
},
{
"id": "authors:z54pq-69f03",
"collection": "authors",
"collection_id": "z54pq-69f03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131002-100802038",
"type": "article",
"title": "The Mass-Metallicity Relation of a z ~ 2 Protocluster with MOSFIRE",
"author": [
{
"family_name": "Kulas",
"given_name": "Kristin R.",
"clpid": "Kulas-K-R"
},
{
"family_name": "McLean",
"given_name": "Ian S.",
"clpid": "McLean-I-S"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Konidaris",
"given_name": "Nicholas P.",
"orcid": "0000-0003-1905-2815",
"clpid": "Konidaris-N-P"
},
{
"family_name": "Matthews",
"given_name": "Keith D.",
"clpid": "Matthews-K-D"
},
{
"family_name": "Mace",
"given_name": "Gregory N.",
"orcid": "0000-0001-7875-6391",
"clpid": "Mace-G-N"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
}
],
"abstract": "We present Keck/MOSFIRE observations of the role of environment in the formation of galaxies at z ~ 2. Using K-band spectroscopy of H\u03b1 and [N\u2009ii] emission lines, we have analyzed the metallicities of galaxies within and around a z = 2.3 protocluster discovered in the HS1700+643 field. Our main sample consists of 23 protocluster and 20 field galaxies with estimates of stellar masses and gas-phase metallicities based on the N2 strong-line metallicity indicator. With these data we have examined the mass\u2013metallicity relation with respect to environment at z ~ 2. We find that field galaxies follow the well-established trend between stellar mass and metallicity, such that more massive galaxies have larger metallicities. The protocluster galaxies, however, do not exhibit a dependence of metallicity on mass, with the low-mass protocluster galaxies showing an enhancement in metallicity compared to field galaxies spanning the same mass range. A comparison with galaxy formation models suggests that the mass-dependent environmental trend we observed can be qualitatively explained in the context of the recycling of \"momentum-driven\" galaxy wind material. Accordingly, winds are recycled on a shorter timescale in denser environments, leading to an enhancement in metallicity at fixed mass for all but the most massive galaxies. Future hydrodynamical simulations of z ~ 2 overdensities matching the one in the HS1700 field will be crucial for understanding the origin of the observed environmental trend in detail.",
"doi": "10.1088/0004-637X/774/2/130",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2013-09-10",
"series_number": "2",
"volume": "774",
"issue": "2",
"pages": "Art. No. 130"
},
{
"id": "authors:m4x1p-n1j94",
"collection": "authors",
"collection_id": "m4x1p-n1j94",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130909-104553617",
"type": "article",
"title": "A measurement of galaxy halo mass from the surrounding H i Ly\u03b1 absorption",
"author": [
{
"family_name": "Rakic",
"given_name": "Olivera",
"clpid": "Rakic-O"
},
{
"family_name": "Schaye",
"given_name": "Joop",
"clpid": "Schaye-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Booth",
"given_name": "C. M.",
"clpid": "Booth-C-M"
},
{
"family_name": "Dalla Vecchia",
"given_name": "Claudio",
"clpid": "Dalla-Vecchia-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
}
],
"abstract": "We measure the dark matter halo masses of \u3008z\u3009 \u2248 2.36 UV colour-selected star-forming galaxies by matching the observed median H I Ly\u03b1 absorption around them, as observed in the spectra of background QSOs, to the absorption around haloes above a given mass in cosmological simulations. Focusing on transverse separations 0\u20132 proper Mpc (pMpc) and line-of-sight separations 154\u2013616\u2009km\u2009s^(\u22121), we find a minimum halo mass of log_(10)M_(min)/M\u2299 = 11.6 \u00b1 0.2, which is in good agreement with published halo mass estimates from clustering analyses. We verified that the measured halo mass is insensitive to a change in the cosmological parameters (Wilkinson Microwave Anisotropy Probe 1 versus Wilkinson Microwave Anisotropy Probe 3) and to the inclusion of strong AGN feedback. One unique strength of this method is that it can be used in narrow field galaxy\u2013QSO surveys, i.e. \u224830 \u00d7 30\u2009arcsec. In addition, we find that the observed anisotropy in the 2D H I Ly\u03b1 absorption distribution on scales of 1.5\u20132\u2009pMpc is consistent with being a consequence of large-scale gas infall into the potential wells occupied by galaxies.",
"doi": "10.1093/mnras/stt950",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2013-08",
"series_number": "4",
"volume": "433",
"issue": "4",
"pages": "3103-3114"
},
{
"id": "authors:fpx9v-zt321",
"collection": "authors",
"collection_id": "fpx9v-zt321",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130516-074741446",
"type": "article",
"title": "The Column Density Distribution and Continuum Opacity of the Intergalactic and Circumgalactic Medium at Redshift =2.4",
"author": [
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "We present new high-precision measurements of the opacity of the intergalactic and circumgalactic medium (IGM, CGM) at =2.4. Using Voigt profile fits to the full Lyman alpha and Lyman beta forests in 15 high-resolution high-S/N spectra of hyperluminous QSOs, we make the first statistically robust measurement of the frequency of absorbers with HI column densities 14\u227elog(N_(HI))\u227e 17.2. We also present the first measurements of the frequency distribution of HI absorbers in the volume surrounding high-z galaxies (the CGM, 300 pkpc), finding that the incidence of absorbers in the CGM is much higher than in the IGM. In agreement with Rudie et al. (2012), we find that there are fractionally more high-N_(HI) absorbers than low-N_(HI) absorbers in the CGM compared to the IGM, leading to a shallower power law fit to the CGM frequency distribution. We use these new measurements to calculate the total opacity of the IGM and CGM to hydrogen-ionizing photons, finding significantly higher opacity than most previous studies, especially from absorbers with log(N_(HI))< 17.2. Reproducing the opacity measured in our data as well as the incidence of absorbers with log(N_(HI)/cm^(-2)) > 17.2 requires a broken power law parameterization of the frequency distribution with a break near log(N^(HI))\u224810^(15)cm^(-2). We compute new estimates of the mean free path \u03bb_(mfp) to hydrogen-ionizing photons at Z_(em)=2.4, finding \u03bb_(mfp) = 147 + 15 Mpc when considering only IGM opacity. If instead, we consider photons emanating from a high-z star-forming galaxy and account for the local excess opacity due to the surrounding CGM of the galaxy itself, the mean free path is reduced to \u03bb_(mfp) = 121 + 15 Mpc. These \u03bb_(mfp) measurements are smaller than recent estimates and should inform future studies of the metagalactic UV background and of ionizing sources at z\u22482-3.",
"doi": "10.1088/0004-637X/769/2/146",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2013-06-01",
"series_number": "2",
"volume": "769",
"issue": "2",
"pages": "Art. No. 146"
},
{
"id": "authors:mwz40-sac38",
"collection": "authors",
"collection_id": "mwz40-sac38",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130613-092507120",
"type": "article",
"title": "The explosion energy of early stellar populations: the Fe-peak element ratios in low-metallicity damped Ly\u03b1 systems",
"author": [
{
"family_name": "Cooke",
"given_name": "Ryan",
"orcid": "0000-0001-7653-5827",
"clpid": "Cooke-R-J"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Jorgenson",
"given_name": "Regina A.",
"clpid": "Jorgenson-R-A"
},
{
"family_name": "Murphy",
"given_name": "Michael T.",
"clpid": "Murphy-M-T"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "The relative abundances of the Fe-peak elements (Ti\u2013Zn) at the lowest metallicities are intimately linked to the physics of core-collapse supernova explosions. With a sample of 25 very metal poor damped Ly\u03b1 systems (DLAs), we investigate the trends of the Fe-peak element ratios with metallicity. For nine of the 25 DLAs, a direct measurement (or useful upper limit) of one or more of the Ti, Cr, Co, Ni, Zn/Fe abundance ratios could be determined from detected absorption lines. For the remaining systems (without detections), we devised a new form of spectral stacking to estimate the typical Fe-peak element ratios of the DLA population in this metallicity regime. We compare these data to analogous measurements in metal-poor stars of the Galactic halo and to detailed calculations of explosive nucleosynthesis in metal-free stars. We conclude that most of the DLAs in our sample were enriched by stars that released an energy of \u22721.2 \u00d7 10^(51) erg when they exploded as core-collapse supernovae. Finally, we discuss the exciting prospect of measuring Fe-peak element ratios in DLAs with Fe/H < 1/1000 of solar when 30-m class telescopes become available. Only then will we be able to pin down the energy that was released by the supernovae of the first stars.",
"doi": "10.1093/mnras/stt282",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2013-05",
"series_number": "2",
"volume": "431",
"issue": "2",
"pages": "1625-1637"
},
{
"id": "authors:n8rpc-eb272",
"collection": "authors",
"collection_id": "n8rpc-eb272",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130402-103239789",
"type": "article",
"title": "A Refined Estimate of the Ionizing Emissivity from Galaxies at z \u2243 3: Spectroscopic Follow-up in the SSA22a Field",
"author": [
{
"family_name": "Nestor",
"given_name": "Daniel B.",
"clpid": "Nestor-D-B"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Kornei",
"given_name": "Katherine A.",
"clpid": "Kornei-K-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Siana",
"given_name": "Brian",
"orcid": "0000-0002-4935-9511",
"clpid": "Siana-Brian-D"
}
],
"abstract": "We investigate the contribution of star-forming galaxies to the ionizing background at z ~ 3, building on previous work based on narrowband (NB3640) imaging in the SSA22a field. We use new Keck/LRIS spectra of Lyman break galaxies (LBGs) and narrowband-selected Ly\u03b1 emitters (LAEs) to measure redshifts for 16 LBGs and 87 LAEs at z > 3.055, such that our NB3640 imaging probes the Lyman-continuum (LyC) region. When we include the existing set of spectroscopically confirmed LBGs, our total sample with z > 3.055 consists of 41 LBGs and 91 LAEs, of which 9 LBGs and 20 LAEs are detected in our NB3640 image. With our combined imaging and spectroscopic data sets, we critically investigate the origin of NB3640 emission for detected LBGs and LAEs. We remove from our samples three LBGs and three LAEs with spectroscopic evidence of contamination of their NB3640 flux by foreground galaxies and statistically model the effects of additional, unidentified foreground contaminants. The resulting contamination and LyC-detection rates, respectively, are 62% \u00b1 13% and 8% \u00b1 3% for our LBG sample, and 47% \u00b1 10% and 12% \u00b1 2% for our LAE sample. The corresponding ratios of non-ionizing UV to LyC flux density, corrected for intergalactic medium (IGM) attenuation, are 18.0^(+34.8)_(\u20137.4) for LBGs and 3.7^(+2.5)_(\u20131.1) for LAEs. We use these ratios to estimate the total contribution of star-forming galaxies to the ionizing background and the hydrogen photoionization rate in the IGM, finding values larger than, but consistent with, those measured in the Ly\u03b1 forest. Finally, the measured UV to LyC flux-density ratios imply model-dependent LyC escape fractions of f^(LyC)_(esc) ~ 5%-7% for our LBG sample and f^(LyC)_(esc) ~ 10%-30% for our fainter LAE sample.",
"doi": "10.1088/0004-637X/765/1/47",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2013-03-01",
"series_number": "1",
"volume": "765",
"issue": "1",
"pages": "Art. No. 47"
},
{
"id": "authors:h3jx5-r6604",
"collection": "authors",
"collection_id": "h3jx5-r6604",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130509-112648069",
"type": "article",
"title": "Wallace L. W. Sargent (1935\u20132012)",
"author": [
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "By any measure, Professor Wallace L. W. Sargent (known to colleagues and friends as \"Wal\") was one of the most influential and consistently productive astronomers of the last 50 years; he authored or coauthored more than 320 refereed journal articles, which have received more than 25,000 citations. He never rested on past laurels\u201465 of his papers (with >5000 citations) have appeared since the year 2000. Wal remained active as a teacher and researcher until just weeks before the end of his life (he officially retired from the Caltech faculty on 2012 October 1). His impact on the field of astrophysics was remarkably broad as well as seminal; among many other awards, he was elected in 1981 as a Fellow of the Royal Society (U.K.) and as a member of the National Academy of Sciences in 2005, his first year of eligibility after becoming a naturalized U.S. citizen.",
"doi": "10.1086/669931",
"issn": "0004-6280",
"publisher": "Astronomical Society of the Pacific",
"publication": "Publications of the Astronomical Society of the Pacific",
"publication_date": "2013-03",
"series_number": "925",
"volume": "125",
"issue": "925",
"pages": "225-226"
},
{
"id": "authors:xg01k-7fd97",
"collection": "authors",
"collection_id": "xg01k-7fd97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130108-115006064",
"type": "article",
"title": "Discovery of multiphase cold accretion in a massive galaxy at z = 0.7",
"author": [
{
"family_name": "Kacprzak",
"given_name": "Glenn G.",
"clpid": "Kacprzak-G-G"
},
{
"family_name": "Churchill",
"given_name": "Christopher W.",
"clpid": "Churchill-C-W"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Spitler",
"given_name": "Lee R.",
"clpid": "Spitler-L-R"
},
{
"family_name": "Holtzman",
"given_name": "Jon A.",
"clpid": "Holtzman-J-A"
}
],
"abstract": "We present detailed photo+collisional ionization models and kinematic models of the multiphase absorbing gas, detected within the Hubble Space Telescope(HST)/COS, HST/STIS and Keck/HIRES spectra of the background quasar TON 153 at 104\u2009kpc along the projected minor axis of a star-forming spiral galaxy (z = 0.6610). Complementary g\u2032r\u2032i\u2032Ks photometry and stellar population models indicate that the host galaxy is dominated by an \u223c4 Gyr stellar population with slightly greater than solar metallicity and has an estimated log\u2009M* = 11 and a log\u2009M_vir = 13. Photoionization models of the low-ionization absorption (Mg\u2009i, Si\u2009ii, Mg\u2009ii and C\u2009iii), which trace the bulk of hydrogen, constrain the multicomponent gas to be cold (log T = 3.8\u20135.2) and metal poor (inline image). A lagging halo model reproduces the low-ionization absorption kinematics, suggesting gas coupled to the disc angular momentum, consistent with cold accretion mode material in simulations. The C\u2009iv and O\u2009vi absorption is best modelled in a separate collisionally ionized metal-poor (\u22122.50 \u2264 [X/H] \u2264 \u22121.93) warm phase with log T = 5.3. Although their kinematics are consistent with a wind model, given the 2\u20132.5 dex difference between the galaxy stellar metallicity and the absorption metallicity we indicate that the gas cannot arise from galactic winds. We discuss and conclude that although the quasar sightline passes along the galaxy minor axis at a projected distance of 0.3 virial radii, well inside its virial shock radius, the combination of the relative kinematics, temperatures and relative metallicities indicates that the multiphase absorbing gas arises from cold accretion around this massive galaxy. Our results appear to contradict recent interpretations that absorption probing the projected minor axis of a galaxy is sampling winds.",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2012-12-21",
"series_number": "4",
"volume": "427",
"issue": "4",
"pages": "3029-3043"
},
{
"id": "authors:4mb1e-3ev53",
"collection": "authors",
"collection_id": "4mb1e-3ev53",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121219-095633258",
"type": "article",
"title": "Stellar Populations of Ultraviolet-selected Active Galactic Nuclei Host Galaxies at z ~ 2\u20133",
"author": [
{
"family_name": "Hainline",
"given_name": "Kevin N.",
"orcid": "0000-0003-4565-8239",
"clpid": "Hainline-K-N"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Greene",
"given_name": "Jenny E.",
"clpid": "Greene-J-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
}
],
"abstract": "We use stellar population synthesis modeling to analyze the host-galaxy properties of a sample of 33 UV-selected, narrow-lined active galactic nuclei (AGNs) at z ~ 2-3. In order to quantify the contribution of AGN emission to host galaxy broadband spectral energy distributions (SEDs), we use the subsample of 11 AGNs with photometric coverage spanning from rest-frame UV through near-IR wavelengths. Modeling the SEDs of these objects with a linear combination of stellar population and AGN templates, we infer the effect of the AGN on derived stellar population parameters. We also estimate the typical bias in derived stellar populations for AGNs lacking rest-frame near-IR wavelength coverage, and develop a method for inferring the true host-galaxy properties. We compare AGN host-galaxy properties to those of a sample of UV-selected, star-forming non-AGNs in the same redshift range, including a subsample carefully matched in stellar mass. Although the AGNs have higher masses and star-formation rates than the full non-active sample, their stellar population properties are consistent with those of the mass-selected sample, suggesting that the presence of an AGN is not connected with the cessation of star formation activity in star-forming galaxies at z ~ 2-3. We suggest that a correlation between M_(BH) and galaxy stellar mass is already in place at this epoch. Assuming a roughly constant Eddington ratio for AGNs at all stellar masses, we are unable to detect the AGNs in low-mass galaxies because they are simply too faint.",
"doi": "10.1088/0004-637X/760/1/74",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-11-20",
"series_number": "1",
"volume": "760",
"issue": "1",
"pages": "Art. No. 74"
},
{
"id": "authors:g4tp2-r4773",
"collection": "authors",
"collection_id": "g4tp2-r4773",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121218-102207465",
"type": "article",
"title": "Quenched Cold Accretion of a Large-scale Metal-poor Filament due to Virial Shocking in the Halo of a Massive z = 0.7 Galaxy",
"author": [
{
"family_name": "Churchill",
"given_name": "Christopher W.",
"clpid": "Churchill-C-W"
},
{
"family_name": "Kacprzak",
"given_name": "Glenn G.",
"clpid": "Kacprzak-G-G"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Spitler",
"given_name": "Lee R.",
"clpid": "Spitler-L-R"
},
{
"family_name": "Holtzman",
"given_name": "Jon",
"clpid": "Holtzman-J-A"
},
{
"family_name": "Nielsen",
"given_name": "Nikole M.",
"orcid": "0000-0003-2377-8352",
"clpid": "Nielsen-N-M"
},
{
"family_name": "Trujillo-Gomez",
"given_name": "Sebastian",
"clpid": "Trujillo-Gomez-S"
}
],
"abstract": "Using HST/COS/STIS and HIRES/Keck high-resolution spectra, we have studied a remarkable H I absorbing complex at z = 0.672 toward the quasar Q1317+277. The H I absorption has a velocity spread of \u0394v = 1600 km s^(\u20131), comprises 21 Voigt profile components, and resides at an impact parameter of D = 58 kpc from a bright, high-mass (log M_(vir)/M_\u2609 \u2243 13.7) elliptical galaxy that is deduced to have a 6 Gyr old, solar metallicity stellar population. Ionization models suggest the majority of the structure is cold gas surrounding a shock-heated cloud that is kinematically adjacent to a multi-phase group of clouds with detected C III, C IV, and O VI absorption, suggestive of a conductive interface near the shock. The deduced metallicities are consistent with the moderate in situ enrichment relative to the levels observed in the z ~ 3 Ly\u03b1 forest. We interpret the H I complex as a metal-poor filamentary structure being shock heated as it accretes into the halo of the galaxy. The data support the scenario of an early formation period (z > 4) in which the galaxy was presumably fed by cold-mode gas accretion that was later quenched via virial shocking by the hot halo such that, by intermediate redshift, the cold filamentary accreting gas is continuing to be disrupted by shock heating. Thus, continued filamentary accretion is being mixed into the hot halo, indicating that the star formation of the galaxy will likely remain quenched. To date, the galaxy and the H I absorption complex provide some of the most compelling observational data supporting the theoretical picture in which accretion is virial shocked in the hot coronal halos of high-mass galaxies.",
"doi": "10.1088/0004-637X/760/1/68",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-11-20",
"series_number": "1",
"volume": "760",
"issue": "1",
"pages": "Art. No. 68"
},
{
"id": "authors:15y0z-r9n70",
"collection": "authors",
"collection_id": "15y0z-r9n70",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121217-112707609",
"type": "article",
"title": "A HST/WFC3-IR Morphological Survey of Galaxies at z = 1.5-3.6. II. The Relation between Morphology and Gas-phase Kinematics",
"author": [
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Nagy",
"given_name": "Sarah R.",
"clpid": "Nagy-S-R"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
}
],
"abstract": "We analyze rest-frame optical morphologies and gas-phase kinematics as traced by rest-frame far-UV and optical spectra for a sample of 204 star-forming galaxies in the redshift range z ~ 2-3 drawn from the Keck Baryonic Structure Survey. We find that spectroscopic properties and gas-phase kinematics are closely linked to morphology: compact galaxies with semimajor axis radii r \u227e 2 kpc are substantially more likely than their larger counterparts to exhibit Ly\u03b1 in emission. Although Ly\u03b1 emission strength varies widely within galaxies of a given morphological type, all but one of 19 galaxies with Ly\u03b1 equivalent width W_(Ly\u03b1) > 20 \u00c5 have compact and/or multiple-component morphologies with r \u2264 2.5 kpc. The velocity structure of absorption lines in the galactic continuum spectra also varies as a function of morphology. Galaxies of all morphological types drive similarly strong outflows (as traced by the blue wing of interstellar absorption line features), but the outflows of larger galaxies are less highly ionized and exhibit larger optical depth at the systemic redshift that may correspond to a decreasing efficiency of feedback in evacuating gas from the galaxy. This v ~ 0 km s^(\u20131) gas is responsible both for shifting the mean absorption line redshift and attenuating W_(Ly\u03b1) (via a longer resonant scattering path) in galaxies with larger rest-optical half-light radii. In contrast to galaxies at lower redshifts, there is no evidence for a correlation between outflow velocity and inclination, suggesting that outflows from these puffy and irregular systems may be poorly collimated. Our observations are broadly consistent with theoretical models of inside-out growth of galaxies in the young universe, in which typical z ~ 2-3 star-forming galaxies are predominantly unstable, dispersion-dominated, systems fueled by rapid gas accretion that later form extended rotationally supported disks when stabilized by a sufficiently massive stellar component.",
"doi": "10.1088/0004-637X/759/1/29",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-11-01",
"series_number": "1",
"volume": "759",
"issue": "1",
"pages": "Art. No. 29"
},
{
"id": "authors:1t6vt-kve74",
"collection": "authors",
"collection_id": "1t6vt-kve74",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120918-142739382",
"type": "article",
"title": "The Temperature-Density Relation in the Intergalactic Medium at Redshift = 2.4",
"author": [
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "We present new measurements of the temperature-density (T-\u03c1) relation for neutral hydrogen in the 2.0 < z < 2.8 intergalactic medium (IGM) using a sample of ~6000 individual H I absorbers fitted with Voigt profiles constrained in all cases by multiple Lyman series transitions. We find model-independent evidence for a positive correlation between the column density of H I (N_(HI)) and the minimum observed velocity width of absorbers (b_(min)). With minimal interpretation, this implies that the T-\u03c1 relation in the IGM is not \"inverted,\" contrary to many recent studies. Fitting b_(min) as a function of N_(HI) results in line-width-column-density dependence of the form b_(min) = b_0(N_(HI)/N_(HI,0))^(\u0393\u20131) with a minimum line width at mean density (\u03c1/\u03c1 = 1, N_(HI,0) = 10^(13.6) cm^(\u20132)) of b_0 = 17.9 \u00b1 0.2 km s^(\u20131) and a power-law index of (\u0393 \u2013 1) = 0.15 \u00b1 0.02. Using analytic arguments, these measurements imply an \"equation of state\" for the IGM at (z) = 2.4 of the form T=T_0 (\u03c1/\u03c1)^(y-1) with a temperature at mean density of T_0 = [1.94 \u00b1 0.05] \u00d7 10^4 K and a power-law index (\u03b3 \u2013 1) = 0.46 \u00b1 0.05.",
"doi": "10.1088/2041-8205/757/2/L30",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2012-10-01",
"series_number": "2",
"volume": "757",
"issue": "2",
"pages": "L30-L35"
},
{
"id": "authors:gcz6e-3cf44",
"collection": "authors",
"collection_id": "gcz6e-3cf44",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120807-145459722",
"type": "article",
"title": "The Characteristic Star Formation Histories of Galaxies at Redshifts z ~ 2-7",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
}
],
"abstract": "A large sample of spectroscopically confirmed star-forming galaxies at redshifts 1.4 \u2264 z_(spec) \u2264 3.7, with\ncomplementary imaging in the near- and mid-IR from the ground and from the Hubble Space Telescope and\nSpitzer Space Telescope, is used to infer the average star formation histories (SFHs) of typical galaxies from z \u223c 2\nto 7. For a subset of 302 galaxies at 1.5 \u2264 z_(spec) < 2.6, we perform a detailed comparison of star formation rates\n(SFRs) determined from spectral energy distribution (SED) modeling (SFRs[SED]) and those calculated from deep\nKeck UV and Spitzer/MIPS 24\u03bcm imaging (SFRs[IR+UV]). Exponentially declining SFHs yield SFRs[SED]\nthat are 5\u201310 times lower on average than SFRs[IR+UV], indicating that declining SFHs may not be accurate for\ntypical galaxies at z \u2273 2. The SFRs of z \u223c 2\u20133 galaxies are directly proportional to their stellar masses (M_*),\nwith unity slope\u2014a result that is confirmed with Spitzer/IRAC stacks of 1179 UV-faint (R > 25.5) galaxies\u2014for\nM_* \u2273 5 \u00d7 10^8M_\u2299 and SFRs \u2273 2M_\u2299 yr^(\u22121). We interpret this result in the context of several systematic biases that\ncan affect determinations of the SFR\u2013M_* relation. The average specific SFRs at z \u223c 2\u20133 are remarkably similar\nwithin a factor of two to those measured at z \u2273 4, implying that the average SFH is one where SFRs increase with\ntime. A consequence of these rising SFHs is that (1) a substantial fraction of UV-bright z \u223c 2\u20133 galaxies had faint\nsub-L* progenitors at z \u2273 4; and (2) gas masses must increase with time from z = 2 to 7, over which time the\nnet cold gas accretion rate\u2014as inferred from the specific SFR and the Kennicutt\u2013Schmidt relation\u2014is \u223c2\u20133 times\nlarger than the SFR. However, if we evolve to higher redshift the SFHs and masses of the halos that are expected\nto host L* galaxies at z \u223c 2, then we find that \u227e10% of the baryons accreted onto typical halos at z \u2273 4 actually\ncontribute to star formation at those epochs. These results highlight the relative inefficiency of star formation even\nat early cosmic times when galaxies were first assembling.",
"doi": "10.1088/0004-637X/754/1/25",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-07-20",
"series_number": "1",
"volume": "754",
"issue": "1",
"pages": "Art. No. 25"
},
{
"id": "authors:90qry-bx065",
"collection": "authors",
"collection_id": "90qry-bx065",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120810-145208297",
"type": "article",
"title": "High velocity dispersion in a rare grand-design spiral galaxy at redshift z = 2.18",
"author": [
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Christensen",
"given_name": "Charlotte R.",
"clpid": "Christensen-C-R"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
}
],
"abstract": "Although grand-design spiral galaxies are relatively common in the local Universe, only one has been spectroscopically confirmed to lie at redshift z\u2009>\u20092 (HDFX 28; z = 2.011); and it may prove to be a major merger that simply resembles a spiral in projection. The rarity of spirals has been explained as a result of disks being dynamically 'hot' at z\u2009>\u20092 (refs 2-5), which may instead favour the formation of commonly observed clumpy structures. Alternatively, current instrumentation may simply not be sensitive enough to detect spiral structures comparable to those in the modern Universe. At z\u2009<\u20092, the velocity dispersion of disks decreases, and spiral galaxies are more numerous by z\u2009\u2248\u20091 (refs 7, 13-15). Here we report observations of the grand-design spiral galaxy Q2343-BX442 at z = 2.18. Spectroscopy of ionized gas shows that the disk is dynamically hot, implying an uncertain origin for the spiral structure. The kinematics of the galaxy are consistent with a thick disk undergoing a minor merger, which can drive the formation of short-lived spiral structure. A duty cycle of <100\u2009Myr for such tidally induced spiral structure in a hot massive disk is consistent with its rarity.",
"doi": "10.1038/nature11256",
"issn": "0028-0836",
"publisher": "Nature Publishing Group",
"publication": "Nature",
"publication_date": "2012-07-19",
"series_number": "7407",
"volume": "487",
"issue": "7407",
"pages": "338-340"
},
{
"id": "authors:gmfpk-prr22",
"collection": "authors",
"collection_id": "gmfpk-prr22",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120716-102035050",
"type": "article",
"title": "The Halo Masses and Galaxy Environments of Hyperluminous QSOs at z \u2243 2.7 in the Keck Baryonic Structure Survey",
"author": [
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present an analysis of the galaxy distribution surrounding 15 of the most luminous (\u227310^(14) L_\u2609; M_1450 \u2243 \u201330) QSOs in the sky with z \u2243 2.7. Our data are drawn from the Keck Baryonic Structure Survey, which has been optimized to examine the small-scale interplay between galaxies and the intergalactic medium during the peak of the galaxy formation era at z ~ 2-3. In this work, we use the positions and spectroscopic redshifts of 1558 galaxies that lie within ~3' (4.2 h^(\u20131) comoving Mpc; cMpc) of the hyperluminous QSO (HLQSO) sight line in 1 of 15 independent survey fields, together with new measurements of the HLQSO systemic redshifts. By combining the spatial and redshift distributions, we measure the galaxy-HLQSO cross-correlation function, the galaxy-galaxy autocorrelation function, and the characteristic scale of galaxy overdensities surrounding the sites of exceedingly rare, extremely rapid, black hole accretion. On average, the HLQSOs lie within significant galaxy overdensities, characterized by a velocity dispersion \u03c3_v \u2243 200 km s^(\u20131) and a transverse angular scale of ~25\" (~200 physical kpc). We argue that such scales are expected for small groups with log (M _(h_/M_\u2609) \u2243 13. The galaxy-HLQSO cross-correlation function has a best-fit correlation length r^(GQ)_0 = (7.3 \u00b1 1.3) h^(\u20131) cMpc, while the galaxy autocorrelation measured from the spectroscopic galaxy sample in the same fields has r^(GG)_0 = (6.0 \u00b1 0.5) h^(\u20131) cMpc. Based on a comparison with simulations evaluated at z ~ 2.6, these values imply that a typical galaxy lives in a host halo with log (M_(h)/M_\u2609) = 11.9 \u00b1 0.1, while HLQSOs inhabit host halos of log (M_(h)/M_\u2609) = 12.3 \u00b1 0.5. In spite of the extremely large black hole masses implied by their observed luminosities [log (M_(BH)/M_\u2609) \u2273 9.7], it appears that HLQSOs do not require environments very different from their much less luminous QSO counterparts. Evidently, the exceedingly low space density of HLQSOs (\u2272 10^(\u20139) cMpc^(\u20133)) results from a one-in-a-million event on scales \u226a1 Mpc, and not from being hosted by rare dark matter halos.",
"doi": "10.1088/0004-637X/752/1/39",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-06-10",
"series_number": "1",
"volume": "752",
"issue": "1",
"pages": "Art. No. 39"
},
{
"id": "authors:a4n9w-fzz83",
"collection": "authors",
"collection_id": "a4n9w-fzz83",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120620-141602544",
"type": "article",
"title": "Neutral Hydrogen Optical Depth near Star-forming Galaxies at z \u2248 2.4 in the Keck Baryonic Structure Survey",
"author": [
{
"family_name": "Rakic",
"given_name": "Olivera",
"clpid": "Rakic-O"
},
{
"family_name": "Schaye",
"given_name": "Joop",
"clpid": "Schaye-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
}
],
"abstract": "We study the interface between galaxies and the intergalactic medium by measuring the absorption by neutral hydrogen in the vicinity of star-forming galaxies at z \u2248 2.4. Our sample consists of 679 rest-frame UV-selected galaxies with spectroscopic redshifts that have impact parameters <2 (proper) Mpc to the line of sight of one of the 15 bright, background QSOs and that fall within the redshift range of its Ly\u03b1 forest. We present the first two-dimensional maps of the absorption around galaxies, plotting the median Ly\u03b1 pixel optical depth as a function of transverse and line-of-sight separation from galaxies. The Ly\u03b1 optical depths are measured using an automatic algorithm that takes advantage of all available Lyman series lines. The median optical depth, and hence the median density of atomic hydrogen, drops by more than an order of magnitude around 100 kpc, which is similar to the virial radius of the halos thought to host the galaxies. The median remains enhanced, at the >3\u03c3 level, out to at least 2.8 Mpc (i.e., >9 comoving Mpc), but the scatter at a given distance is large compared with the median excess optical depth, suggesting that the gas is clumpy. Within 100 (200) kpc, and over \u00b1165 km s^(\u20131), the covering fraction of gas with Ly\u03b1 optical depth greater than unity is 100^(+0)_(\u201332%) (66% \u00b1 16%). Absorbers with \u03c4_(Ly\u03b1) > 0.1 are typically closer to galaxies than random. The mean galaxy overdensity around absorbers increases with the optical depth and also as the length scale over which the galaxy overdensity is evaluated is decreased. Absorbers with \u03c4_(Ly\u03b1) ~ 1 reside in regions where the galaxy number density is close to the cosmic mean on scales \u22650.25 Mpc. We clearly detect two types of redshift space anisotropies. On scales <200 km s^(\u20131), or <1 Mpc, the absorption is stronger along the line of sight than in the transverse direction. This \"finger of God\" effect may be due to redshift errors, but is probably dominated by gas motions within or very close to the halos. On the other hand, on scales of 1.4-2.0 Mpc the absorption is compressed along the line of sight (with >3\u03c3 significance), an effect that we attribute to large-scale infall (i.e., the Kaiser effect).",
"doi": "10.1088/0004-637X/751/2/94",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-06-01",
"series_number": "2",
"volume": "751",
"issue": "2",
"pages": "Art. No. 94"
},
{
"id": "authors:kcq4t-zvt08",
"collection": "authors",
"collection_id": "kcq4t-zvt08",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120711-142544942",
"type": "article",
"title": "3D-HST: A Wide-field Grism Spectroscopic Survey with the Hubble Space Telescope",
"author": [
{
"family_name": "Brammer",
"given_name": "Gabriel B.",
"orcid": "0000-0003-2680-005X",
"clpid": "Brammer-G-B"
},
{
"family_name": "van Dokkum",
"given_name": "Pieter G.",
"orcid": "0000-0002-8282-9888",
"clpid": "van-Dokkum-P-G"
},
{
"family_name": "Franx",
"given_name": "Marijn",
"orcid": "0000-0002-8871-3026",
"clpid": "Franx-M"
},
{
"family_name": "Fumagalli",
"given_name": "Mattia",
"orcid": "0000-0001-6676-3842",
"clpid": "Fumagalli-M"
},
{
"family_name": "Patel",
"given_name": "Shannon",
"clpid": "Patel-S-G"
},
{
"family_name": "Rix",
"given_name": "Hans-Walter",
"orcid": "0000-0003-4996-9069",
"clpid": "Rix-H-W"
},
{
"family_name": "Skelton",
"given_name": "Rosalind E.",
"clpid": "Skelton-R-E"
},
{
"family_name": "Kriek",
"given_name": "Mariska",
"orcid": "0000-0002-7613-9872",
"clpid": "Kriek-M"
},
{
"family_name": "Nelson",
"given_name": "Erica",
"orcid": "0000-0002-7524-374X",
"clpid": "Nelson-E-J"
},
{
"family_name": "Schmidt",
"given_name": "Kasper B.",
"clpid": "Schmidt-K-B"
},
{
"family_name": "Bezanson",
"given_name": "Rachel",
"clpid": "Bezanson-R"
},
{
"family_name": "da Cunha",
"given_name": "Elisabete",
"orcid": "0000-0001-9759-4797",
"clpid": "da-Cunha-E"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Fan",
"given_name": "Xiaohui",
"orcid": "0000-0003-3310-0131",
"clpid": "Fan-Xiaohui"
},
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "Natascha",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Illingworth",
"given_name": "Garth D.",
"orcid": "0000-0002-6668-2011",
"clpid": "Illingworth-G-D"
},
{
"family_name": "Labb\u00e9",
"given_name": "Ivo",
"orcid": "0000-0002-2057-5376",
"clpid": "Labb\u00e9-I"
},
{
"family_name": "Leja",
"given_name": "Joel",
"orcid": "0000-0001-6755-1315",
"clpid": "Leja-J"
},
{
"family_name": "Lundgren",
"given_name": "Britt",
"clpid": "Lundgren-B"
},
{
"family_name": "Magee",
"given_name": "Dan",
"clpid": "Magee-D-K"
},
{
"family_name": "Marchesini",
"given_name": "Danilo",
"orcid": "0000-0001-9002-3502",
"clpid": "Marchesini-D"
},
{
"family_name": "McCarthy",
"given_name": "Patrick",
"clpid": "McCarthy-P-J"
},
{
"family_name": "Momcheva",
"given_name": "Ivelina",
"clpid": "Momcheva-I-G"
},
{
"family_name": "Muzzin",
"given_name": "Adam",
"orcid": "0000-0002-9330-9108",
"clpid": "Muzzin-A"
},
{
"family_name": "Quadri",
"given_name": "Ryan",
"clpid": "Quadri-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Tal",
"given_name": "Tomer",
"clpid": "Tal-Tomer"
},
{
"family_name": "Wake",
"given_name": "David",
"clpid": "Wake-D"
},
{
"family_name": "Whitaker",
"given_name": "Katherine E.",
"orcid": "0000-0001-7160-3632",
"clpid": "Whitaker-K-E"
},
{
"family_name": "Williams",
"given_name": "Anna",
"clpid": "Williams-A"
}
],
"abstract": "We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying\nthe physical processes that shape galaxies in the distant universe. 3D-HST provides rest-frame optical spectra for\na sample of \u223c7000 galaxies at 1 < z < 3.5, the epoch when \u223c60% of all star formation took place, the number\ndensity of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in\ngalaxies today must have emerged. 3D-HST will cover three quarters (625 arcmin^2) of the CANDELS Treasury\nsurvey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L\ngrism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of \u223c5 per resolution element\nat H_140 \u223c 23.1 and a 5\u03c3 emission-line sensitivity of \u223c5 \u00d7 10^(\u221217) erg s^\u22121 cm^(\u22122) for typical objects, improving by\na factor of \u223c2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide\ncontinuous wavelength coverage from 1.1 to 1.6\u03bcm at a spatial resolution of \u223c0.\"13, which, combined with their\ndepth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary\nreduction and analysis of the grism observations, including emission-line and redshift measurements from combined\nfits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis\nyields redshift estimates with a precision of \u03c3(z) = 0.0034(1 + z), or \u03c3(v) \u2248 1000 km s^(\u22121). We illustrate how\nthe generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types\nof objects, including a quasar at z = 4.7, quiescent galaxies at z \u223c 2, and the most distant T-type brown dwarf\nstar known. The combination of the CANDELS and 3D-HST surveys will provide the definitive imaging and\nspectroscopic data set for studies of the 1 < z < 3.5 universe until the launch of the James Webb Space Telescope.",
"doi": "10.1088/0067-0049/200/2/13",
"issn": "0067-0049",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Supplement Series",
"publication_date": "2012-06",
"series_number": "2",
"volume": "200",
"issue": "2",
"pages": "Art. No. 13"
},
{
"id": "authors:hgr8t-fm882",
"collection": "authors",
"collection_id": "hgr8t-fm882",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120313-074331194",
"type": "article",
"title": "The Gaseous Environment of High-z Galaxies: Precision Measurements of Neutral Hydrogen in the Circumgalactic Medium of z ~ 2-3 Galaxies in the Keck Baryonic Structure Survey",
"author": [
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Trainor",
"given_name": "Ryan F.",
"orcid": "0000-0002-6967-7322",
"clpid": "Trainor-R-F"
},
{
"family_name": "Rakic",
"given_name": "Olivera",
"clpid": "Rakic-O"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Reddy",
"given_name": "Naveen",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
}
],
"abstract": "We present results from the Keck Baryonic Structure Survey (KBSS), a unique spectroscopic survey of the\ndistant universe designed to explore the details of the connection between galaxies and intergalactic baryons\nwithin the same survey volumes, focusing particularly on scales from \u223c 50 kpc to a few Mpc. The KBSS is\noptimized for the redshift range z \u223c 2-3, combining S/N \u223c 100 Keck/HIRES spectra of 15 of the brightest\nQSOs in the sky at z \u2243 2.5-2.9 with very densely sampled galaxy redshift surveys within a few arcmin of each\nQSO sightline. In this paper, we present quantitative results on the distribution, column density, kinematics,\nand absorber line widths of neutral hydrogen (H_I) surrounding a subset of 886 KBSS star-forming galaxies\nwith 2.0 \u227e z \u227e 2.8 and with projected distances \u2264 3 physical Mpc from a QSO sightline. Using Voigt profile\ndecompositions of the full Ly\u03b1 forest region of all 15 QSO spectra, we compiled a catalog of \u223c6000 individual\nabsorbers in the redshift range of interest, with 12 \u2264 log(N_(HI)) \u2264 21. These are used to measure H I absorption\nstatistics near the redshifts of foreground galaxies as a function of projected galactocentric distance from the\nQSO sightline and for randomly chosen locations in the intergalacticmedium (IGM) within the survey volume.\nWe find that NHI and the multiplicity of velocity-associated H I components increase rapidly with decreasing\ngalactocentric impact parameter and as the systemic redshift of the galaxy is approached. The strongest H_I\nabsorbers within \u2243 100 physical kpc of galaxies have N_(HI) \u223c 3 orders of magnitude higher than those near\nrandom locations in the IGM. The circumgalactic zone of most significantly enhanced H_I absorption is found\nwithin transverse distances of \u227e 300 kpc and within \u00b1300 km s^(-1) of galaxy systemic redshifts. Taking this\nregion as the defining bounds of the circumgalactic medium (CGM), nearly half of absorbers with log(N_(HI))\n> 15.5 are found within the CGM of galaxies meeting our photometric selection criteria, while their CGM\noccupy only 1.5% of the cosmic volume. The spatial covering fraction, multiplicity of absorption components,\nand characteristic NHI remain significantly elevated to transverse distances of \u223c2 physical Mpc from galaxies\nin our sample. Absorbers with N_(HI) > 10^(14.5) cm^(-2) are tightly correlated with the positions of galaxies, while\nabsorbers with lower N_(HI) are correlated with galaxy positions only on \u2273 Mpc scales. Redshift anisotropies\non these larger scales indicate coherent infall toward galaxy locations, while on scales of \u223c 100 physical kpc\npeculiar velocities of \u0394v \u2243 \u00b1260 km s^(-1) with respect to the galaxies are indicated. The median Doppler widths\nof individual absorbers within 1-3 r_(vir) of galaxies are larger by \u2243 50% than randomly chosen absorbers of the\nsame NHI, suggesting higher gas temperatures and/or increased turbulence likely caused by some combination\nof accretion shocks and galactic winds around galaxies with M_(halo) \u2243 10^(12) M_\u2299 at z \u223c 2-3.",
"doi": "10.1088/0004-637X/750/1/67",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-05-01",
"series_number": "1",
"volume": "750",
"issue": "1",
"pages": "Art. No. 67"
},
{
"id": "authors:fk194-dv379",
"collection": "authors",
"collection_id": "fk194-dv379",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120403-092029054",
"type": "article",
"title": "The Kinematics of Multiple-Peaked Ly\u03b1 Emission in Star-Forming Galaxies at z ~ 2-3",
"author": [
{
"family_name": "Kulas",
"given_name": "Kristin R.",
"clpid": "Kulas-K-R"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Kollmeier",
"given_name": "Juna A.",
"orcid": "0000-0001-9852-1610",
"clpid": "Kollmeier-J-A"
},
{
"family_name": "Zheng",
"given_name": "Zheng",
"clpid": "Zheng-Zheng"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Hainline",
"given_name": "Kevin N.",
"orcid": "0000-0003-4565-8239",
"clpid": "Hainline-K-N"
}
],
"abstract": "We present new results on the Ly\u03b1 emission-line kinematics of 18 z ~ 2-3 star-forming galaxies with multiple-peaked Ly\u03b1 profiles. With our large spectroscopic database of UV-selected star-forming galaxies at these redshifts, we have determined that ~30% of such objects with detectable Ly\u03b1 emission display multiple-peaked emission profiles. These profiles provide additional constraints on the escape of Ly\u03b1 photons due to the rich velocity structure in the emergent line. Despite recent advances in modeling the escape of Ly\u03b1 from star-forming galaxies at high redshifts, comparisons between models and data are often missing crucial observational information. Using Keck II NIRSPEC spectra of H\u03b1 (z ~ 2) and [O III]\u03bb5007 (z ~ 3), we have measured accurate systemic redshifts, rest-frame optical nebular velocity dispersions, and emission-line fluxes for the objects in the sample. In addition, rest-frame UV luminosities and colors provide estimates of star formation rates and the degree of dust extinction. In concert with the profile sub-structure, these measurements provide critical constraints on the geometry and kinematics of interstellar gas in high-redshift galaxies. Accurate systemic redshifts allow us to translate the multiple-peaked Ly\u03b1 profiles into velocity space, revealing that the majority (11/18) display double-peaked emission straddling the velocity-field zero point with stronger red-side emission. Interstellar absorption-line kinematics suggest the presence of large-scale outflows for the majority of objects in our sample, with an average measured interstellar absorption velocity offset of (\u0394v_(abs))=\u2013230 km s^(\u20131). A comparison of the interstellar absorption kinematics for objects with multiple- and single-peaked Ly\u03b1 profiles indicate that the multiple-peaked objects are characterized by significantly narrower absorption line widths. We compare our data with the predictions of simple models for outflowing and infalling gas distributions around high-redshift galaxies. While popular \"shell\" models provide a qualitative match with many of the observations of Ly\u03b1 emission, we find that in detail there are important discrepancies between the models and data, as well as problems with applying the framework of an expanding thin shell of gas to explain high-redshift galaxy spectra. Our data highlight these inconsistencies, as well as illuminating critical elements for success in future models of outflow and infall in high-redshift galaxies.",
"doi": "10.1088/0004-637X/745/1/33",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-01-20",
"series_number": "1",
"volume": "745",
"issue": "1",
"pages": "Art. No. 33"
},
{
"id": "authors:q43e5-mf376",
"collection": "authors",
"collection_id": "q43e5-mf376",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120403-093455017",
"type": "article",
"title": "An HST/WFC3-IR Morphological Survey of Galaxies at z = 1.5-3.6. I. Survey Description and Morphological Properties of Star-forming Galaxies",
"author": [
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Nagy",
"given_name": "Sarah R.",
"clpid": "Nagy-S-R"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
}
],
"abstract": "We present the results of a 42-orbit Hubble Space Telescope Wide-Field Camera 3 (HST/WFC3) survey of the rest-frame optical morphologies of star-forming galaxies with spectroscopic redshifts in the range z = 1.5-3.6. The survey consists of 42 orbits of F160W imaging covering ~65 arcmin2 distributed widely across the sky and reaching a depth of 27.9 AB for a 5\u03c3 detection within a 0.2 arcsec radius aperture. Focusing on an optically selected sample of 306 star-forming galaxies with stellar masses in the range M_* = 10^9-10^(11) M_\u2609, we find that typical circularized effective half-light radii range from ~0.7 to 3.0 kpc and describe a stellar mass-radius relation as early as z ~ 3. While these galaxies are best described by an exponential surface brightness profile (S\u00e9rsic index n ~ 1), their distribution of axis ratios is strongly inconsistent with a population of inclined exponential disks and is better reproduced by triaxial stellar systems with minor/major and intermediate/major axis ratios ~0.3 and 0.7, respectively. While rest-UV and rest-optical morphologies are generally similar for a subset of galaxies with HST/Advanced Camera for Surveys imaging data, differences are more pronounced at higher masses M_* > 3 \u00d7 10^(10) M_\u2609. Finally, we discuss galaxy morphology in the context of efforts to constrain the merger fraction, finding that morphologically identified mergers/non-mergers generally have insignificant differences in terms of physical observables such as stellar mass and star formation rate, although merger-like galaxies selected according to some criteria have statistically smaller effective radii and correspondingly larger \u03a3_(SFR).",
"doi": "10.1088/0004-637X/745/1/85",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2012-01-20",
"series_number": "1",
"volume": "745",
"issue": "1",
"pages": "Art. No. 85"
},
{
"id": "authors:w6gby-04495",
"collection": "authors",
"collection_id": "w6gby-04495",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120104-141106508",
"type": "article",
"title": "First Results from the 3D-HST Survey: The Striking Diversity of Massive Galaxies at z > 1",
"author": [
{
"family_name": "van Dokkum",
"given_name": "Pieter G.",
"orcid": "0000-0002-8282-9888",
"clpid": "van-Dokkum-P-G"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present first results from the 3D-HST program, a near-IR spectroscopic survey performed with the Wide Field Camera 3 (WFC3) on the HST. We have used 3D-HST spectra to measure redshifts and H\u03b1 equivalent widths (EWH\u03b1) for a complete, stellar mass-limited sample of 34 galaxies at 1 < z < 1.5 with M_(star) > 10^(11) M_\u2609 in the COSMOS, GOODS, and AEGIS fields. We find that a substantial fraction of massive galaxies at this epoch are forming stars at a high rate: the fraction of galaxies with EW_(H\u03b1) >10 \u00c5 is 59%, compared to 10% among Sloan Digital Sky Survey galaxies of similar masses at z = 0.1. Galaxies with weak H\u03b1 emission show absorption lines typical of 2-4 Gyr old stellar populations. The structural parameters of the galaxies, derived from the associated WFC3 F140W imaging data, correlate with the presence of H\u03b1; quiescent galaxies are compact with high S\u00e9rsic index and high inferred velocity dispersion, whereas star-forming galaxies are typically large two-armed spiral galaxies, with low S\u00e9rsic index. Some of these star-forming galaxies might be progenitors of the most massive S0 and Sa galaxies. Our results challenge the idea that galaxies at fixed mass form a homogeneous population with small scatter in their properties. Instead, we find that massive galaxies form a highly diverse population at z > 1, in marked contrast to the local universe.",
"doi": "10.1088/2041-8205/743/1/L15",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2011-12-10",
"series_number": "1",
"volume": "743",
"issue": "1",
"pages": "Art. No. L15"
},
{
"id": "authors:ssyfm-ssn06",
"collection": "authors",
"collection_id": "ssyfm-ssn06",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111014-095153900",
"type": "article",
"title": "Filamentary Large-scale Structure Traced by Six Ly\u03b1 Blobs at z = 2.3",
"author": [
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "Extended nebulae of Ly\u03b1 emission (\"Ly\u03b1 blobs\") are known to be associated with overdense regions at high redshift. Here we present six large Ly\u03b1 blobs in a previously known protocluster with galaxy overdensity \u03b4 ~ 7 at z = 2.3; this is the richest field of giant Ly\u03b1 blobs detected to date. The blobs have linear sizes of \u2273 100 kpc and Ly\u03b1 luminosities of ~10^(43) erg s^(\u20131). The positions of the blobs define two linear filaments with an extent of at least 12 comoving Mpc; these filaments intersect at the center of one of the blobs. Measurement of the position angles of the blobs indicates that five of the six are aligned with these filaments to within ~10\u00b0, suggesting a connection between the physical processes powering extended Ly\u03b1 emission and those driving structure on larger scales.",
"doi": "10.1088/2041-8205/740/1/L31",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2011-10-10",
"series_number": "1",
"volume": "740",
"issue": "1",
"pages": "Art. No. L31"
},
{
"id": "authors:xgyjk-40n30",
"collection": "authors",
"collection_id": "xgyjk-40n30",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120103-144527695",
"type": "article",
"title": "The most metal-poor damped Ly\u03b1 systems: insights into chemical\n evolution in the very metal-poor regime",
"author": [
{
"family_name": "Cooke",
"given_name": "Ryan",
"orcid": "0000-0001-7653-5827",
"clpid": "Cooke-R-J"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Nissen",
"given_name": "Poul E.",
"clpid": "Nissen-P-E"
}
],
"abstract": "We present a high spectral resolution survey of the most metal-poor damped Ly\u03b1 absorption systems (DLAs) aimed at probing the nature and nucleosynthesis of the earliest generations of stars. Our survey comprises 22 systems with iron abundance less than 1/100 solar; observations of seven of these are reported here for the first time. Together with recent measures of the abundances of C and O in Galactic metal-poor stars, we reinvestigate the trend of C/O in the very metal-poor (VMP) regime and we compare, for the first time, the O/Fe ratios in the most metal-poor DLAs and in halo stars. We confirm the near-solar values of C/O in DLAs at the lowest metallicities probed, and find that their distribution is in agreement with that seen in Galactic halo stars. We find that the O/Fe ratio in VMP DLAs is essentially constant, and shows very little dispersion, with a mean [\u3008O/Fe\u3009]=+0.39 \u00b1 0.12, in good agreement with the values measured in Galactic halo stars when the oxygen abundance is measured from the [O i] \u03bb6300 line. We speculate that such good agreement in the observed abundance trends points to a universal origin for these metals. In view of this agreement, we construct the abundance pattern for a typical VMP DLA and compare it to model calculations of Population II and Population III nucleosynthesis to determine the origin of the metals in VMP DLAs. Our results suggest that the most metal-poor DLAs may have been enriched by a generation of metal-free stars; however, given that abundance measurements are currently available for only a few elements, we cannot yet rule out an additional contribution from Population II stars.",
"doi": "10.1111/j.1365-2966.2011.19365.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2011-10",
"series_number": "2",
"volume": "417",
"issue": "2",
"pages": "1534-1558"
},
{
"id": "authors:wyasa-mr612",
"collection": "authors",
"collection_id": "wyasa-mr612",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111115-094620008",
"type": "article",
"title": "Morphological properties of z ~ 0.5 absorption-selected galaxies: the role of galaxy inclination",
"author": [
{
"family_name": "Kacprzak",
"given_name": "Glenn G.",
"clpid": "Kacprzak-G-G"
},
{
"family_name": "Churchill",
"given_name": "Christopher W.",
"clpid": "Churchill-C-W"
},
{
"family_name": "Evans",
"given_name": "Jessica L.",
"clpid": "Evans-J-L"
},
{
"family_name": "Murphy",
"given_name": "Michael T.",
"clpid": "Murphy-M-T"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We have used Galaxy IMage 2D (GIM2D) to quantify the morphological properties of 40 intermediate-redshift Mg ii absorption-selected galaxies [0.03 \u2264\u2002W_r(2796) \u2264 2.9 \u00c5], imaged with WFPC-2/Hubble Space Telescope\u2002(HST), and compared them to the halo gas properties measured from HIRES/Keck and UVES/VLT quasar spectra. We find that as the quasar\u2013galaxy separation,\u2002D, increases the Mg ii equivalent decreases with large scatter, implying that\u2002D\u2002 is not the only physical parameter affecting the distribution and quantity of halo gas. Our main result shows that inclination correlates with Mg ii absorption properties after normalizing out the relationship (and scatter) between the absorption properties and\u2002D. We find a 4.3\u03c3 correlation between\u2002W_r(2796) and galaxy inclination, normalized by impact parameter,\u2002i/D. Other measures of absorption optical depth also correlate with\u2002i/D\u2002at greater than 3.2\u03c3 significance. Overall, this result suggests that Mg ii gas has a co-planer geometry, not necessarily disc-like, that is coupled to the galaxy inclination. It is plausible that the absorbing gas arises from tidal streams, satellites, filaments, etc., which tend to have somewhat co-planer distributions. This result does not support a picture in which Mg ii absorbers with\u2002W_r(2796) \u2272 1 \u00c5 are predominantly produced by star formation driven winds.\n\nWe further find that: (1) Mg ii host galaxies have quantitatively similar bulge and disc scalelength distribution to field galaxies at similar redshifts and have a mean disc and bulge scalelength of 3.8 and 2.5 kpc, respectively; (2) Galaxy colour and luminosity do not correlate strongly with absorption properties, implying a lack of a connection between host galaxy star formation rates and absorption strength; and (3) parameters such as scalelengths and bulge-to-total ratios do not significantly correlate with the absorption parameters, suggesting that the absorption is independent of galaxy size or mass.",
"doi": "10.1111/j.1365-2966.2011.19261.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2011-10",
"series_number": "4",
"volume": "416",
"issue": "4",
"pages": "3118-3137"
},
{
"id": "authors:2qgfy-g3e97",
"collection": "authors",
"collection_id": "2qgfy-g3e97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110930-113320403",
"type": "article",
"title": "Constraint on the Assembly and Dynamics of Galaxies. II. Properties of Kiloparsec-Scale Clumps in Rest-Frame Optical Emission of z ~ 2 Star-Forming Galaxies",
"author": [
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Genzel",
"given_name": "R.",
"orcid": "0000-0002-2767-9653",
"clpid": "Genzel-Reinhard"
},
{
"family_name": "Bouch\u00e9",
"given_name": "N.",
"clpid": "Bouch\u00e9-N"
},
{
"family_name": "Cresci",
"given_name": "G.",
"clpid": "Cresci-G"
},
{
"family_name": "Davies",
"given_name": "R.",
"clpid": "Davies-R"
},
{
"family_name": "Erb",
"given_name": "D. K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Genel",
"given_name": "S.",
"orcid": "0000-0002-3185-1540",
"clpid": "Genel-S"
},
{
"family_name": "Lutz",
"given_name": "D.",
"orcid": "0000-0003-0291-9582",
"clpid": "Lutz-Dieter"
},
{
"family_name": "Newman",
"given_name": "S.",
"clpid": "Newman-S-Astro"
},
{
"family_name": "Shapiro",
"given_name": "K. L.",
"clpid": "Shapiro-K-L"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Sternberg",
"given_name": "A.",
"clpid": "Sternberg-A"
},
{
"family_name": "Tacconi",
"given_name": "L. J.",
"orcid": "0000-0002-1485-9401",
"clpid": "Tacconi-Linda-J"
}
],
"abstract": "We study the properties of luminous stellar \"clumps\" identified in deep, high-resolution Hubble Space Telescope NIC2/F160W imaging at 1.6 \u03bcm of six z ~ 2 star-forming galaxies with existing near-infrared integral field spectroscopy from SINFONI at the Very Large Telescope. Individual clumps contribute ~0.5%-15% of the galaxy-integrated rest-frame \u22485000 \u00c5 emission, with median of \u22482%; the total contribution of clump light ranges from 10% to 25%. The median intrinsic clump size and stellar mass are ~1 kpc and ~10^9 M_\u2609, in the ranges for clumps identified in rest-UV or line emission in other studies. The clump sizes and masses in the subset of disks are broadly consistent with expectations for clump formation through gravitational instabilities in gas-rich, turbulent disks given the host galaxies' global properties. By combining the NIC2 data with Advanced Camera for Surveys (ACS)/F814W imaging available for one source, and adaptive-optics-assisted SINFONI H\u03b1 data for another, we infer modest color, M/L, and stellar age variations within each galaxy. In these two objects, sets of clumps identified at different wavelengths do not fully overlap; NIC2-identified clumps tend to be redder/older than ACS- or H\u03b1-identified clumps without rest-frame optical counterparts. There is evidence for a systematic trend of older ages at smaller galactocentric radii among the clumps, consistent with scenarios where inward migration of clumps transports material toward the central regions. From constraints on a bulge-like component at radii \u227e1-3 kpc, none of the five disks in our sample appears to contain a compact massive stellar core, and we do not discern a trend of bulge stellar mass fraction with stellar age of the galaxy. Further observations are necessary to probe the buildup of stellar bulges and the role of clumps in this process.",
"doi": "10.1088/0004-637X/739/1/45",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2011-09-20",
"series_number": "1",
"volume": "739",
"issue": "1",
"pages": "Art. No. 45"
},
{
"id": "authors:4amrh-54010",
"collection": "authors",
"collection_id": "4amrh-54010",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110902-103429209",
"type": "article",
"title": "Diffuse Ly\u03b1 Emitting Halos: A Generic Property of High-redshift Star-forming Galaxies",
"author": [
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Kollmeier",
"given_name": "Juna A.",
"orcid": "0000-0001-9852-1610",
"clpid": "Kollmeier-J-A"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "Using a sample of 92 UV continuum-selected, spectroscopically identified galaxies with langzrang = 2.65, all of which have been imaged in the Ly\u03b1 line with extremely deep narrow-band imaging, we examine galaxy Ly\u03b1 emission profiles to very faint surface brightness limits. The galaxy sample is representative of spectroscopic samples of Lyman break galaxies (LBGs) at similar redshifts in terms of apparent magnitude, UV luminosity, inferred extinction, and star formation rate and was assembled without regard to Ly\u03b1 emission properties. Approximately 45% (55%) of the galaxy spectra have Ly\u03b1 appearing in net absorption (emission), with \u224320% satisfying commonly used criteria for the identification of \"Ly\u03b1 emitters\" (LAEs; W 0(Ly\u03b1) \u2265 20 \u00c5). We use extremely deep stacks of rest-UV continuum and continuum-subtracted Ly\u03b1 images to show that all sub-samples exhibit diffuse Ly\u03b1 emission to radii of at least 10\" (~80 physical kpc). The characteristic exponential scale lengths for Ly\u03b1 line emission exceed that of the \u03bb_0 = 1220 \u00c5 UV continuum light by factors of ~5-10. The surface brightness profiles of Ly\u03b1 emission are strongly suppressed relative to the UV continuum light in the inner few kpc, by amounts that are tightly correlated with the galaxies' observed spectral morphology; however, all galaxy sub-subsamples, including that of galaxies for which Ly\u03b1 appears in net absorption in the spectra, exhibit qualitatively similar diffuse Ly\u03b1 emission halos. Accounting for the extended Ly\u03b1 emission halos, which generally would not be detected in the slit spectra of individual objects or with typical narrow-band Ly\u03b1 imaging, increases the total Ly\u03b1 flux (and rest equivalent width W _0(Ly\u03b1)) by an average factor of ~5, and by a much larger factor for the 80% of LBGs not classified as LAEs. We argue that most, if not all, of the observed Ly\u03b1 emission in the diffuse halos originates in the galaxy H II regions but is scattered in our direction by H I gas in the galaxy's circum-galactic medium. The overall intensity of Ly\u03b1 halos, but not the surface brightness distribution, is strongly correlated with the emission observed in the central ~1\" \u2014more luminous halos are observed for galaxies with stronger central Ly\u03b1 emission. We show that whether or not a galaxy is classified as a giant \"Ly\u03b1 blob\" (LAB) depends sensitively on the Ly\u03b1 surface brightness threshold reached by an observation. Accounting for diffuse Ly\u03b1 halos, all LBGs would be LABs if surveys were sensitive to 10 times lower Ly\u03b1 surface brightness thresholds; similarly, essentially all LBGs would qualify as LAEs.",
"doi": "10.1088/0004-637X/736/2/160",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2011-08-01",
"series_number": "2",
"volume": "736",
"issue": "2",
"pages": "Art. No. 160"
},
{
"id": "authors:d2hm7-7t796",
"collection": "authors",
"collection_id": "d2hm7-7t796",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110802-091358495",
"type": "article",
"title": "Narrowband Imaging of Escaping Lyman-continuum Emission in the SSA22 Field",
"author": [
{
"family_name": "Nestor",
"given_name": "Daniel B.",
"clpid": "Nestor-D-B"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Siana",
"given_name": "Brian",
"orcid": "0000-0002-4935-9511",
"clpid": "Siana-Brian-D"
}
],
"abstract": "We present the results of an ultradeep, narrowband imaging survey for Lyman-continuum (LyC) emission at z ~ 3 in the SSA22a field. We employ a custom narrowband filter centered at \u03bb = 3640 \u00c5 (NB3640), which probes the LyC region for galaxies at z \u2265 3.06. We also analyze new and archival NB4980 imaging tuned to the wavelength of the Ly\u03b1 emission line at z = 3.09, and archival broadband B, V, and R images of the non-ionizing UV continuum. Our NB3640 images contain 26 z \u2265 3.06 Lyman break galaxies (LBGs) as well as a set of 130 Ly\u03b1 emitters (LAEs), identified by their excess NB4980 flux relative to the BV continuum. Six LBGs and 28 LAEs are detected in the NB3640 image. LBGs appear to span a range of NB3640-R colors, while LAEs appear bimodal in their NB3640-R properties. We estimate average UV-to-LyC flux density ratios, corrected for foreground contamination and intergalactic medium absorption, finding (F_(UV)/F_(LyC)^(LBG)_(corr) = 11.3^(+10.3)_(\u20135.4), which implies an LBG LyC escape fraction f^(LyC)_(esc) ~ 0.1, and (F_(UV)/F_(LyC)^(LAE)_(corr) = 2.2^(+0.9)_(\u20130.6). The strikingly blue LAE flux density ratios defy interpretation in terms of standard stellar population models. Assuming (F _(UV)/F_(LyC)^(LBG)_(corr) applies down to L = 0.1L^*, we estimate a galaxy contribution to the intergalactic hydrogen ionization rate that is consistent with independent estimates based on the Ly\u03b1 forest opacity at z sime 3. If we assume that (F_(UV)/F_(LyC)^(LAE)_(corr) holds at the faintest luminosities, the galaxy contribution significantly exceeds that inferred from the Ly\u03b1 forest. We interpret our results in terms of a model where LyC photons escape over only ~10%-20% of solid angle. When advantageously oriented, a galaxy will exhibit a low UV-to-LyC ratio, an effect enhanced for more compact galaxies. This model, however, does not adequately explain the extremely blue NB3640-R colors measured for some LAEs in our sample. Further follow-up study of these faint LAEs is crucial, given the potentially important contribution similar objects make to the process of reionization.",
"doi": "10.1088/0004-637X/736/1/18",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2011-07-20",
"series_number": "1",
"volume": "736",
"issue": "1",
"pages": "Art. No. 18"
},
{
"id": "authors:d8x4z-fnk15",
"collection": "authors",
"collection_id": "d8x4z-fnk15",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110816-082413937",
"type": "article",
"title": "The Mass\u2013Radius Relation for Star-forming Galaxies at z ~ 1.5-3.0",
"author": [
{
"family_name": "Nagy",
"given_name": "Sarah R.",
"clpid": "Nagy-S-R"
},
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present early results from a Hubble Space Telescope WFC3/IR imaging survey of star-forming galaxies in the redshift range 1.5 < z < 3.0. When complete, this survey will consist of 42 orbits of F160W imaging distributed amongst 10 survey fields on the line of sight to bright background QSOs, covering 65 arcmin^2 to a depth of 27.9 AB with a point-spread function FWHM of 0\".18. In this contribution, we use a subset of these fields to explore the evolution of the galactic stellar mass-radius relation for a magnitude-limited sample of 102 spectroscopically confirmed star-forming galaxies ((SFR) ~ 30 M_\u2609 yr^(\u20131)) with stellar mass M_* ~ 10^(10) M_\u2609. Although the light profile of these galaxies often has an irregular, multi-component morphology, it is typically possible to describe the brightest component with a Sersic profile of index n ~ 1. The circularized half-light radius r e of the brightest component is on average r_e = 1.66 \u00b1 0.79 kpc (i.e., ~50%-70% the size of local late-type galaxies with similar stellar mass), consistent with recent theoretical models that incorporate strong feedback from star-forming regions. The mean half-light radius increases with stellar mass and, at fixed stellar mass, evolves with cosmic time as ~(1 + z)^(\u20131.42), suggesting that high-redshift star-forming galaxies may evolve onto the local stellar mass-radius relation by redshift z ~ 1.",
"doi": "10.1088/2041-8205/735/1/L19",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2011-07-01",
"series_number": "1",
"volume": "735",
"issue": "1",
"pages": "Art. No. L19"
},
{
"id": "authors:affq3-mgh65",
"collection": "authors",
"collection_id": "affq3-mgh65",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110812-111221376",
"type": "article",
"title": "Calibrating galaxy redshifts using absorption by the surrounding intergalactic medium",
"author": [
{
"family_name": "Rakic",
"given_name": "Olivera",
"clpid": "Rakic-O"
},
{
"family_name": "Schaye",
"given_name": "Joop",
"clpid": "Schaye-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
}
],
"abstract": "Rest-frame UV spectral lines of star-forming galaxies are systematically offset from the galaxies' systemic redshifts, probably because of large-scale outflows. We calibrate galaxy redshifts measured from rest-frame UV lines by utilizing the fact that the mean H i Ly\u03b1 absorption profiles around the galaxies, as seen in spectra of background objects, must be symmetric with respect to the true galaxy redshifts if the galaxies are oriented randomly with respect to the lines of sight to the background objects. We use 15 bright QSOs at z\u22482.5\u20133 and more than 600 foreground galaxies with spectroscopic redshifts at z\u22481.9\u20132.5. All galaxies are within 2 Mpc proper from the lines of sight to the background QSOs. We find that Ly\u03b1 emission and ISM absorption redshifts require systematic shifts of \u2206\u03bd_Ly\u03b1 = -295^(+35)_(-35) and \u2206\u03bd_ISM = 145^(+70)_(-35) km s^(-1), respectively. Assuming a Gaussian distribution, we put 1\u03c3 upper limits on possible random redshift offsets of <220 km s^(-1) for Ly\u03b1 and <420 km s^(-1) for ISM redshifts. For the small subset (<10 per cent) of galaxies for which near-IR spectra have been obtained, we can compare our results to direct measurements based on rest-frame optical, nebular emission lines, which we confirm to mark the systemic redshifts. While our \u0394vISM agrees with the direct measurements, our \u0394v_Ly\u03b1 is significantly smaller. However, when we apply our method to the near-IR subsample which is characterized by slightly different selection effects, the best-fitting velocity offset comes into agreement with the direct measurement. This confirms the validity of our approach, and implies that no single number appropriately describes the whole population of galaxies, in line with the observation that the line offset depends on galaxy spectral morphology. This method provides accurate redshift calibrations and will enable studies of circumgalactic matter around galaxies for which rest-frame optical observations are not available.",
"doi": "10.1111/j.1365-2966.2011.18624.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2011-07",
"series_number": "4",
"volume": "414",
"issue": "4",
"pages": "3265-3271"
},
{
"id": "authors:7m400-jx918",
"collection": "authors",
"collection_id": "7m400-jx918",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110531-114638789",
"type": "article",
"title": "The Rest-frame Ultraviolet Spectra of UV-selected Active Galactic Nuclei at z ~ 2-3",
"author": [
{
"family_name": "Hainline",
"given_name": "Kevin N.",
"orcid": "0000-0003-4565-8239",
"clpid": "Hainline-Kevin-N"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-Alice-E"
},
{
"family_name": "Greene",
"given_name": "Jenny E.",
"orcid": "0000-0002-5612-3427",
"clpid": "Greene-Jenny-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present new results for a sample of 33 narrow-lined UV-selected active galactic nuclei (AGNs), identified in the course of a spectroscopic survey for star-forming galaxies at z ~ 2-3. The rest-frame UV composite spectrum for our AGN sample shows several emission lines characteristic of AGNs, as well as interstellar absorption features detected in star-forming Lyman break galaxies (LBGs). We report a detection of N iv] \u03bb1486, which has been observed in high-redshift radio galaxies, as well as in rare optically selected quasars. The UV continuum slope of the composite spectrum is significantly redder than that of a sample of non-AGN UV-selected star-forming galaxies. Blueshifted Si iv absorption provides evidence for outflowing highly ionized gas in these objects at speeds of ~10^3 km s^(\u20131), quantitatively different from what is seen in the outflows of non-AGN LBGs. Grouping the individual AGNs by parameters such as the Ly\u03b1 equivalent width, redshift, and UV continuum magnitude allows for an analysis of the major spectroscopic trends within the sample. Stronger Ly\u03b1 emission is coupled with weaker low-ionization absorption, which is similar to what is seen in the non-AGN LBGs, and highlights the role that cool interstellar gas plays in the escape of Ly\u03b1 photons. However, the AGN composite does not show the same trends between Ly\u03b1 strength and extinction seen in the non-AGN LBGs. These results represent the first such comparison at high redshift between star-forming galaxies and similar galaxies that host AGN activity.",
"doi": "10.1088/0004-637X/733/1/31",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2011-05-20",
"series_number": "1",
"volume": "733",
"issue": "1",
"pages": "Art. No. 31"
},
{
"id": "authors:yes84-5ep32",
"collection": "authors",
"collection_id": "yes84-5ep32",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110511-101501949",
"type": "article",
"title": "Constraints on the Assembly and Dynamics of Galaxies. I. Detailed Rest-frame Optical Morphologies on Kiloparsec Scale of z ~ 2 Star-forming Galaxies",
"author": [
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Erb",
"given_name": "D. K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Genzel",
"given_name": "R.",
"orcid": "0000-0002-2767-9653",
"clpid": "Genzel-Reinhard"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Bouch\u00e9",
"given_name": "N.",
"clpid": "Bouch\u00e9-N"
},
{
"family_name": "Cresci",
"given_name": "G.",
"clpid": "Cresci-G"
},
{
"family_name": "Davies",
"given_name": "R.",
"clpid": "Davies-R"
}
],
"abstract": "We present deep and high-resolution Hubble Space Telescope NIC2 F160W imaging at 1.6 \u03bcm of six z ~ 2 star-forming galaxies with existing near-infrared integral field spectroscopy from SINFONI at the Very Large Telescope. The unique combination of rest-frame optical imaging and nebular emission-line maps provides simultaneous insight into morphologies and dynamical properties. The overall rest-frame optical emission of the galaxies is characterized by shallow profiles in general (S\u00e9rsic index n < 1), with median effective radii of R_e ~ 5 kpc. The morphologies are significantly clumpy and irregular, which we quantify through a non-parametric morphological approach, estimating the Gini (G), multiplicity (\u03a8), and M_(20) coefficients. The estimated strength of the rest-frame optical emission lines in the F160W bandpass indicates that the observed structure is not dominated by the morphology of line-emitting gas, and must reflect the underlying stellar mass distribution of the galaxies. The sizes and structural parameters in the rest-frame optical continuum and H\u03b1 emission reveal no significant differences, suggesting similar global distributions of the ongoing star formation and more evolved stellar population. While no strong correlations are observed between stellar population parameters and morphology within the NIC2/SINFONI sample itself, a consideration of the sample in the context of a broader range of z ~ 2 galaxy types (K-selected quiescent, active galactic nucleus, and star forming; 24 \u03bcm selected dusty, infrared-luminous) indicates that these galaxies probe the high specific star formation rate and low stellar mass surface density part of the massive z ~ 2 galaxy population, with correspondingly large effective radii, low S\u00e9rsic indices, low G, and high \u03a8 and M_(20). The combined NIC2 and SINFONI data set yields insights of unprecedented detail into the nature of mass accretion at high redshift.",
"doi": "10.1088/0004-637X/731/1/65",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2011-04-10",
"series_number": "1",
"volume": "731",
"issue": "1",
"pages": "Art. No. 65"
},
{
"id": "authors:z1p1m-6yq41",
"collection": "authors",
"collection_id": "z1p1m-6yq41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110426-092303862",
"type": "article",
"title": "A carbon-enhanced metal-poor damped Ly\u03b1 system: probing gas from Population III nucleosynthesis?",
"author": [
{
"family_name": "Cooke",
"given_name": "Ryan",
"orcid": "0000-0001-7653-5827",
"clpid": "Cooke-R-J"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Jorgenson",
"given_name": "Regina A.",
"clpid": "Jorgenson-R-A"
}
],
"abstract": "We present high-resolution observations of an extremely metal-poor damped Ly\u03b1 system (DLA), at z_(abs) = 2.340 0972 in the spectrum of the QSO J0035\u22120918, exhibiting an abundance pattern consistent with model predictions for the supernova yields of Population III stars. Specifically, this DLA has [Fe/H]\u2243\u22123, shows a clear 'odd\u2013even' effect, and is C-rich with [C/Fe]=+1.53, a factor of \u223c20 greater than reported in any other DLA. In analogy to the carbon-enhanced metal-poor stars in the Galactic halo (with [C/Fe] > +1.0), this is the first known case of a carbon-enhanced DLA. We determine an upper limit to the mass of ^(12)C, M(^(12)C) \u2264 200 M_\u2299, which depends on the unknown gas density n(H); if n(H) > 1 cm^(\u22123) (which is quite likely for this DLA given its low velocity dispersion), then M(^(12)C) \u2264 2 M_\u2299, consistent with pollution by only a few prior supernovae. We speculate that DLAs such as the one discovered here may represent the 'missing link' between the yields of Population III stars and their later incorporation in the class of carbon-enhanced metal-poor stars which show no enhancement of neutron-capture elements (CEMP-no stars).",
"doi": "10.1111/j.1365-2966.2010.17966.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2011-04",
"series_number": "2",
"volume": "412",
"issue": "2",
"pages": "1047-1058"
},
{
"id": "authors:k431h-c3082",
"collection": "authors",
"collection_id": "k431h-c3082",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110103-110312343",
"type": "article",
"title": "A newly discovered DLA and associated Ly\u03b1 emission in the spectra of the gravitationally lensed quasar UM 673A,B",
"author": [
{
"family_name": "Cooke",
"given_name": "Ryan",
"orcid": "0000-0001-7653-5827",
"clpid": "Cooke-R-J"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "King",
"given_name": "Lindsay J.",
"clpid": "King-L-J"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Rakic",
"given_name": "Olivera",
"clpid": "Rakic-O"
}
],
"abstract": "The sightline to the brighter member of the gravitationally lensed quasar pair UM 673A,B intersects a damped Ly\u03b1 system (DLA) at z = 1.62650 which, because of its low redshift, has not been recognized before. Our high-quality echelle spectra of the pair, obtained with HIRES on the Keck I telescope, show a drop in neutral hydrogen column density N(H i) by a factor of at least 400 between UM 673A and UM 673B, indicating that the DLA's extent in this direction is much less than the 2.7 h^(\u22121)_(70) kpc separation between the two sightlines at z = 1.62650. By re-assessing this new case together with published data on other quasar pairs, we conclude that the typical size (radius) of DLAs at these redshifts is R \u2243 (5 \u00b1 3) h^(\u22121)_(70) kpc, smaller than previously realized. Highly ionized gas associated with the DLA is more extended, as we find only small differences in the C iv absorption profiles between the two sightlines.\n\nCoincident with UM 673B, we detect a weak and narrow Ly\u03b1\u2002emission line which we attribute to star formation activity at a rate SFR \u2273 0.2 M_\u2299 yr^(\u22121). The DLA in UM 673A is metal poor, with an overall metallicity Z_(DLA) \u2243 1/30 Z_\u2299, and has a very low internal velocity dispersion. It exhibits some apparent peculiarities in its detailed chemical composition, with the elements Ti, Ni and Zn being deficient relative to Fe by factors of 2\u20133. The [Zn/Fe] ratio is lower than those measured in any other DLA or Galactic halo star, presumably reflecting somewhat unusual previous enrichment by stellar nucleosynthesis. We discuss the implications of these results for the nature of the galaxy hosting the DLA.",
"doi": "10.1111/j.1365-2966.2010.17331.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2010-12",
"series_number": "2",
"volume": "409",
"issue": "2",
"pages": "679-693"
},
{
"id": "authors:e2h0p-3y711",
"collection": "authors",
"collection_id": "e2h0p-3y711",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101004-101154180",
"type": "article",
"title": "Excess AGN activity in the z = 2.30 Protocluster in HS 1700+64",
"author": [
{
"family_name": "Digby-North",
"given_name": "J. A.",
"clpid": "Digby-North-J-A"
},
{
"family_name": "Nandra",
"given_name": "K.",
"orcid": "0000-0002-7150-9192",
"clpid": "Nandra-K"
},
{
"family_name": "Laird",
"given_name": "E. S.",
"clpid": "Laird-E-S"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Georgakakis",
"given_name": "A.",
"clpid": "Georgakakis-A"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "M.",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Erb",
"given_name": "D. K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Reddy",
"given_name": "N. A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Aird",
"given_name": "J.",
"orcid": "0000-0003-1908-8463",
"clpid": "Aird-J-A"
}
],
"abstract": "We present the results of spectroscopic, narrow-band and X-ray observations of a z= 2.30 protocluster in the field of the QSO HS 1700+643. Using a sample of BX/MD galaxies, which are selected to be at z ~ 2.2\u20132.7 by their rest-frame ultraviolet colours, we find that there are five protocluster AGN which have been identified by characteristic emission-lines in their optical/near-IR spectra; this represents an enhancement over the field significant at >98.5 per cent confidence. Using a ~200-ks Chandra/ACIS-I observation of this field we detect a total of 161 X-ray point sources to a Poissonian false-probability limit of 4 \u00d7 10^(\u22126) and identify eight of these with BX/MD galaxies. Two of these are spectroscopically confirmed protocluster members and are also classified as emission-line AGN. When compared to a similarly selected field sample, the analysis indicates this is also evidence for an enhancement of X-ray selected BX/MD AGN over the field, significant at >99 per cent confidence. Deep Ly\u03b1 narrow-band imaging reveals that a total of 4/123 Ly\u03b1 emitters (LAEs) are found to be associated with X-ray sources, with two of these confirmed protocluster members and one highly likely member. We do not find a significant enhancement of AGN activity in this LAE sample over that of the field (result is significant at only 87 per cent confidence). The X-ray emitting AGN fractions for the BX/MD and LAE samples are found to be 6.9^(+9.2)_(\u22124.4) and 2.9^(+2.9)_(\u22121.6) per cent, respectively, for protocluster AGN with L_(2-10 keV)\u2265 4.6 \u00d7 10^(43) erg s^(\u22121) at z= 2.30. These findings are similar to results from the z= 3.09 protocluster in the SSA 22 field found by Lehmer et al. (2009), in that both suggest AGN activity is favoured in dense environments at z > 2.",
"doi": "10.1111/j.1365-2966.2010.16977.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2010-09-11",
"series_number": "2",
"volume": "407",
"issue": "2",
"pages": "846-853"
},
{
"id": "authors:fb3x1-d2151",
"collection": "authors",
"collection_id": "fb3x1-d2151",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100901-164318892",
"type": "article",
"title": "Physical Conditions in a Young, Unreddened, Low-metallicity Galaxy at High Redshift",
"author": [
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "Increasingly large samples of galaxies are now being discovered at redshifts z ~ 5-6 and higher. Many of these objects are inferred to be young, low in mass, and relatively unreddened, but detailed analysis of their high quality spectra will not be possible until the advent of future facilities. In this paper, we shed light on the physical conditions in a plausibly similar low-mass galaxy by presenting the analysis of the rest-frame optical and UV spectra of Q2343-BX418, an L* galaxy at z = 2.3 with a very low mass-to-light ratio and unusual properties: BX418 is young (<100 Myr), low mass (M_* ~ 109 M_\u2609), low in metallicity (Z ~ 1/6 Z_\u2609), and unreddened (E(B \u2013 V) \u2243 0.02, UV continuum slope \u03b2 = \u20132.1). We infer a metallicity 12 + log(O/H) = 7.9 \u00b1 0.2 from the rest-frame optical emission lines. We also determine the metallicity via the direct, electron temperature method, using the ratio O III] \u03bb\u03bb1661, 1666/[O III] \u03bb5007 to determine the electron temperature and finding 12 + log(O/H) = 7.8 \u00b1 0.1. These measurements place BX418 among the most metal-poor galaxies observed in emission at high redshift. The rest-frame UV spectrum, which represents ~12 hr of integration with the Keck telescope, contains strong emission from Ly\u03b1 (with rest-frame equivalent width 54 \u00c5), He II \u03bb1640 (both stellar and nebular), C III] \u03bb\u03bb1907, 1909 and O III] \u03bb\u03bb1661, 1666. The C IV/C III] ratio indicates that the source of ionization is unlikely to be an active galactic nucleus. Analysis of the He II, O III], and C III] line strengths indicates a very high ionization parameter log U ~ \u20131, while Ly\u03b1 and the interstellar absorption lines indicate that outflowing gas is highly ionized over a wide range of velocities. It remains to be determined how many of BX418's unique spectral features are due to its global properties, such as low metallicity and dust extinction, and how many are indicative of a short-lived phase in the early evolution of an otherwise normal star-forming galaxy.",
"doi": "10.1088/0004-637X/719/2/1168",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2010-08-20",
"series_number": "2",
"volume": "719",
"issue": "2",
"pages": "1168-1190"
},
{
"id": "authors:tz92d-1na85",
"collection": "authors",
"collection_id": "tz92d-1na85",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100709-165047127",
"type": "article",
"title": "The Structure and Kinematics of the Circumgalactic Medium from Far-ultraviolet Spectra of z \u2243 2-3 Galaxies",
"author": [
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
},
{
"family_name": "Rudie",
"given_name": "Gwen C.",
"orcid": "0000-0002-8459-5413",
"clpid": "Rudie-G-C"
},
{
"family_name": "Rakic",
"given_name": "Olivera",
"clpid": "Rakic-O"
}
],
"abstract": "We present new results on the kinematics and spatial distribution of metal-enriched gas within ~125 kpc of star-forming (\"Lyman break\") galaxies at redshifts 2 \u2272 z \u2272 3. In particular, we focus on constraints provided by the rest-frame far-ultraviolet (far-UV) spectra of faint galaxies, and demonstrate how galaxy spectra can be used to obtain key spatial and spectral information more efficiently than possible with QSO sightlines. Using a sample of 89 galaxies with z = 2.3 \u00b1 0.3 and with both rest-frame far-UV and H\u03b1 spectra, we re-calibrate the measurement of accurate galaxy systemic redshifts using only survey-quality rest-UV spectra. We use the velocity-calibrated sample to investigate the kinematics of the galaxy-scale outflows via the strong interstellar (IS) absorption lines and Ly\u03b1 emission (when present), as well as their dependence on other physical properties of the galaxies. We construct a sample of 512 close (1\"-15\") angular pairs of z ~ 2-3 galaxies with redshift differences indicating a lack of physical association. Sightlines to the background galaxies provide new information on the spatial distribution of circumgalactic gas surrounding the foreground galaxies. The close pairs sample galactocentric impact parameters 3-125 kpc (physical) at = 2.2, providing for the first time a robust map of cool gas as a function of galactocentric distance for a well-characterized population of galaxies. We propose a simple model of circumgalactic gas that simultaneously matches the kinematics, depth, and profile shape of IS absorption and Ly\u03b1 emission lines, as well as the observed variation of absorption line strength (H I and several metallic species) versus galactocentric impact parameter. Within the model, cool gas is distributed symmetrically around every galaxy, accelerating radially outward with v_(out)(r) increasing with r (i.e., the highest velocities are located at the largest galactocentric distances r). The inferred radial dependence of the covering fraction of cool gas (which modulates the absorption line strength) is f_c(r) \u221d r^(\u2013\u03b3) with 0.2 \u2272 \u03b3 \u2272 0.6 depending on transition. We discuss the results of the observations in the context of \"cold accretion,\" in which cool gas is accreting via filamentary streams directly onto the central regions of galaxies. At present, we find little observational evidence for cool infalling material, while evidence supporting the large-scale effects of superwind outflows is strong. This \"pilot\" study using faint galaxy spectra demonstrates the potential of using galaxies to trace baryons within galaxies, in the circumgalactic medium, and ultimately throughout the intergalactic medium.",
"doi": "10.1088/0004-637X/717/1/289",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2010-07-01",
"series_number": "1",
"volume": "717",
"issue": "1",
"pages": "289-322"
},
{
"id": "authors:xsjhj-d7g20",
"collection": "authors",
"collection_id": "xsjhj-d7g20",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100407-095436265",
"type": "article",
"title": "Dust Obscuration and Metallicity at High Redshift: New Inferences from UV, H\u03b1, and 8 \u03bcm Observations of z ~ 2 Star-forming Galaxies",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
}
],
"abstract": "We use a sample of 90 spectroscopically confirmed Lyman break galaxies with H\u03b1 measurements and Spitzer MIPS 24 \u03bcm observations to constrain the relationship between rest-frame 8 \u03bcm luminosity (L_8) and star formation rate (SFR) for L* galaxies at z ~ 2. We find a tight correlation with 0.24 dex scatter between L_8 and H\u03b1 luminosity/SFR for z ~ 2 galaxies with 10^(10) L_\u2609 \u2272 L_(IR) \u2272 10^(12) L_\u2609. Employing this relationship with a larger sample of 392 galaxies with spectroscopic redshifts, we find that the UV slope \u03b2 can be used to recover the dust attenuation of the vast majority of moderately luminous L* galaxies at z ~ 2 to within a 0.4 dex scatter using the local correlation. Separately, young galaxies with ages \u2272100 Myr appear to be less dusty than their UV slopes would imply based on the local trend and may follow an extinction curve that is steeper than what is typically assumed. Consequently, very young galaxies at high redshift may be significantly less dusty than inferred previously. Our results provide the first direct evidence, independent of the UV slope, for a correlation between UV and bolometric luminosity (L_(bol)) at high redshift, in the sense that UV-faint galaxies are on average less infrared and less bolometrically luminous than their UV-bright counterparts. The L_(bol)-L_(UV) relation indicates that as the SFR increases, L_(UV) turns over (or \"saturates\") around the value of L* at z ~ 2, implying that dust obscuration may be largely responsible for modulating the bright end of the UV luminosity function. Finally, dust attenuation is found to correlate with oxygen abundance at z ~ 2. Accounting for systematic differences in local and high-redshift metallicity calibrations, we find that L* galaxies at z ~ 2, while at least an order of magnitude more bolometrically luminous, exhibit ratios of metals to dust that are similar to those of local starbursts. This result is expected if high-redshift galaxies are forming their stars in a less metal-rich environment compared to local galaxies of the same luminosity, thus naturally leading to a redshift evolution in both the bolometric luminosity-metallicity and bolometric luminosity-obscuration relations.",
"doi": "10.1088/0004-637X/712/2/1070",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2010-04-01",
"series_number": "2",
"volume": "712",
"issue": "2",
"pages": "1070-1091"
},
{
"id": "authors:hwk92-kds45",
"collection": "authors",
"collection_id": "hwk92-kds45",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100317-113658511",
"type": "article",
"title": "Halo Gas and Galaxy Disk Kinematics Derived from Observations and \u039bCDM Simulations of Mg II Absorption-selected Galaxies at Intermediate Redshift",
"author": [
{
"family_name": "Kacprzak",
"given_name": "Glenn G.",
"clpid": "Kacprzak-G-G"
},
{
"family_name": "Churchill",
"given_name": "Christopher W.",
"clpid": "Churchill-C-W"
},
{
"family_name": "Ceverino",
"given_name": "Daniel",
"orcid": "0000-0002-8680-248X",
"clpid": "Ceverino-D"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Klypin",
"given_name": "Anatoly",
"clpid": "Klypin-A"
},
{
"family_name": "Murphy",
"given_name": "Michael T.",
"clpid": "Murphy-M-T"
}
],
"abstract": "We obtained ESI/Keck rotation curves of 10 Mg II absorption-selected galaxies (0.3 \u2264 z \u2264 1.0) for which we have WFPC-2/HST images and high-resolution HIRES/Keck and UVES/VLT quasar spectra of the Mg II absorption profiles. We perform a kinematic comparison of these galaxies and their associated halo Mg II absorption. For all 10 galaxies, the majority of the absorption velocities lie in the range of the observed galaxy rotation velocities. In 7/10 cases, the absorption velocities reside fully to one side of the galaxy systemic velocity and usually align with one arm of the rotation curve. In all cases, a constant rotating thick-disk model poorly reproduces the full spread of observed Mg II absorption velocities when reasonably realistic parameters are employed. In 2/10 cases, the galaxy kinematics, star formation surface densities, and absorption kinematics have a resemblance to those of high-redshift galaxies showing strong outflows. We find that Mg II absorption velocity spread and optical depth distribution may be dependent on galaxy inclination. To further aid in the spatial-kinematic relationships of the data, we apply quasar absorption-line techniques to a galaxy (v_c = 180 km s^(\u20131)) embedded in \u039bCDM simulations. In the simulations, Mg II absorption selects metal-enriched \"halo\" gas out to ~100 kpc from the galaxy, tidal streams, filaments, and small satellite galaxies. Within the limitations inherent in the simulations, the majority of the simulated Mg II absorption arises in the filaments and tidal streams and is infalling toward the galaxy with velocities between \u2013200 km s^(-1) \u2264 v_r \u2264 \u2013180 km s^(\u20131). The Mg II absorption velocity offset distribution (relative to the simulated galaxy) spans ~200 km s^(\u20131) with the lowest frequency of detecting Mg II at the galaxy systematic velocity.",
"doi": "10.1088/0004-637X/711/2/533",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2010-03-10",
"series_number": "2",
"volume": "711",
"issue": "2",
"pages": "533-558"
},
{
"id": "authors:1b7gs-1g970",
"collection": "authors",
"collection_id": "1b7gs-1g970",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100317-111435674",
"type": "article",
"title": "The Relationship between Stellar Populations and Ly\u03b1 Emission in Lyman Break Galaxies",
"author": [
{
"family_name": "Kornei",
"given_name": "Katherine A.",
"clpid": "Kornei-K-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Bogosavljevi\u0107",
"given_name": "Milan",
"clpid": "Bogosavljevi\u0107-M"
}
],
"abstract": "We present the results of a photometric and spectroscopic survey of 321 Lyman break galaxies (LBGs) at z ~ 3 to investigate systematically the relationship between Ly\u03b1 emission and stellar populations. Ly\u03b1 equivalent widths (W_(Ly\u03b1)) were calculated from rest-frame UV spectroscopy and optical/near-infrared/Spitzer photometry was used in population synthesis modeling to derive the key properties of age, dust extinction, star formation rate (SFR), and stellar mass. We directly compare the stellar populations of LBGs with and without strong Ly\u03b1 emission, where we designate the former group (W_(Ly\u03b1) \u2265 20 \u00c5) as Ly\u03b1 emitters (LAEs) and the latter group (W_(Ly\u03b1) < 20 \u00c5) as non-LAEs. This controlled method of comparing objects from the same UV luminosity distribution represents an improvement over previous studies in which the stellar populations of LBGs and narrowband-selected LAEs were contrasted, where the latter were often intrinsically fainter in broadband filters by an order of magnitude simply due to different selection criteria. Using a variety of statistical tests, we find that Ly\u03b1 equivalent width and age, SFR, and dust extinction, respectively, are significantly correlated in the sense that objects with strong Ly\u03b1 emission also tend to be older, lower in SFR, and less dusty than objects with weak Ly\u03b1 emission, or the line in absorption. We accordingly conclude that, within the LBG sample, objects with strong Ly\u03b1 emission represent a later stage of galaxy evolution in which supernovae-induced outflows have reduced the dust covering fraction. We also examined the hypothesis that the attenuation of Ly\u03b1 photons is lower than that of the continuum, as proposed by some, but found no evidence to support this picture.",
"doi": "10.1088/0004-637X/711/2/693",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2010-03-10",
"series_number": "2",
"volume": "711",
"issue": "2",
"pages": "693-710"
},
{
"id": "authors:0m35g-vdw91",
"collection": "authors",
"collection_id": "0m35g-vdw91",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100303-095354486",
"type": "article",
"title": "A study of interstellar gas and stars in the gravitationally lensed galaxy 'the Cosmic Eye' from rest-frame ultraviolet spectroscopy",
"author": [
{
"family_name": "Quider",
"given_name": "Anna M.",
"clpid": "Quider-A-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Stark",
"given_name": "Daniel P.",
"clpid": "Stark-D-P"
}
],
"abstract": "We report the results of a study of the rest-frame ultraviolet (UV) spectrum of the Cosmic Eye (J213512.73\u2212010143) , a luminous (L\u223c 2L*) Lyman break galaxy at z_(sys)= 3.07331 magnified by a factor of ~25 via gravitational lensing by foreground mass concentrations at z= 0.73 and 0.33. The spectrum, recorded at high resolution and signal-to-noise ratio with the Echellette Spectrograph and Imager (ESI) spectrograph on the Keck II telescope, is rich in absorption features from the gas and massive stars in this galaxy. The interstellar absorption lines are resolved into two components of approximately equal strength and each spanning several hundred km s^(\u22121) in velocity. One component has a net blueshift of \u221270 km s^(\u22121) relative to the stars and H II regions and presumably arises in a galaxy-scale outflow similar to those seen in most star-forming galaxies at z= 2\u20133 . The other is more unusual in showing a mean redshift of +350 km s^(\u22121) relative to z_(sys); possible interpretations include a merging clump, or material ejected by a previous star formation episode and now falling back on to the galaxy, or more simply a chance alignment with a foreground galaxy. In the metal absorption lines, both components only partially cover the OB stars against which they are being viewed. However, there must also be more pervasive diffuse gas to account for the near-total covering fraction of the strong damped Ly\u03b1 line, indicative of a column density N(HI) = (3.0 \u00b1 0.8) \u00d7 10^(21) cm^(\u22122) . We tentatively associate this neutral gas with the redshifted component, and propose that it provides the dust 'foreground screen' responsible for the low ratio of far-infrared to UV luminosities of the Cosmic Eye.\n\nThe C IV P Cygni line in the stellar spectrum is consistent with continuous star formation with a Salpeter initial mass function, stellar masses from 5 to 100 M_\u2299 , and a metallicity Z ~ 0.4 Z_\u2299. Compared to other well-studied examples of strongly lensed galaxies, we find that the young stellar population of the Cosmic Eye is essentially indistinguishable from those of the Cosmic Horseshoe and MS 1512\u2212cB58 . On the other hand, the interstellar spectra of all three galaxies are markedly different, attesting to the real complexity of the interplay between starbursts and ambient interstellar matter in young galaxies observed during the epoch when cosmic star formation was at its peak.",
"doi": "10.1111/j.1365-2966.2009.16005.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2010-03-01",
"series_number": "3",
"volume": "402",
"issue": "3",
"pages": "1467-1479"
},
{
"id": "authors:3aqts-8jq44",
"collection": "authors",
"collection_id": "3aqts-8jq44",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100218-101337738",
"type": "article",
"title": "The evolution of the hard X-ray luminosity function of AGN",
"author": [
{
"family_name": "Aird",
"given_name": "J.",
"orcid": "0000-0003-1908-8463",
"clpid": "Aird-J-A"
},
{
"family_name": "Nandra",
"given_name": "K.",
"orcid": "0000-0002-7150-9192",
"clpid": "Nandra-K"
},
{
"family_name": "Laird",
"given_name": "E. S.",
"clpid": "Laird-E-S"
},
{
"family_name": "Georgakakis",
"given_name": "A.",
"clpid": "Georgakakis-A"
},
{
"family_name": "Ashby",
"given_name": "M. L. N.",
"orcid": "0000-0002-3993-0745",
"clpid": "Ashby-M-L-N"
},
{
"family_name": "Barmby",
"given_name": "P.",
"orcid": "0000-0003-2767-0090",
"clpid": "Barmby-P"
},
{
"family_name": "Coil",
"given_name": "A. L.",
"clpid": "Coil-A-L"
},
{
"family_name": "Huang",
"given_name": "J.-S.",
"clpid": "Huang-J-S"
},
{
"family_name": "Koekemoer",
"given_name": "A. M.",
"orcid": "0000-0002-6610-2048",
"clpid": "Koekemoer-A-M"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Willmer",
"given_name": "C. N. A.",
"clpid": "Willmer-C-N-A"
}
],
"abstract": "We present new observational determinations of the evolution of the 2\u201310 keV X-ray luminosity function (XLF) of active galactic nuclei (AGN). We utilize data from a number of surveys including both the 2 Ms Chandra Deep Fields and the AEGIS-X 200 ks survey, enabling accurate measurements of the evolution of the faint end of the XLF. We combine direct, hard X-ray selection and spectroscopic follow-up or photometric redshift estimates at z < 1.2 with a rest-frame UV colour pre-selection approach at higher redshifts to avoid biases associated with catastrophic failure of the photometric redshifts. Only robust optical counterparts to X-ray sources are considered using a likelihood ratio matching technique. A Bayesian methodology is developed that considers redshift probability distributions, incorporates selection functions for our high-redshift samples and allows robust comparison of different evolutionary models. We statistically account for X-ray sources without optical counterparts to correct for incompleteness in our samples. We also account for Poissonian effects on the X-ray flux estimates and sensitivities and thus correct for the Eddington bias. We find that the XLF retains the same shape at all redshifts, but undergoes strong luminosity evolution out to z ~ 1 , and an overall negative density evolution with increasing redshift, which thus dominates the evolution at earlier times. We do not find evidence that a luminosity-dependent density evolution, and the associated flattening of the faint-end slope, is required to describe the evolution of the XLF. We find significantly higher space densities of low-luminosity, high-redshift AGN than in prior studies, and a smaller shift in the peak of the number density to lower redshifts with decreasing luminosity. The total luminosity density of AGN peaks at z= 1.2 \u00b1 0.1 , but there is a mild decline to higher redshifts. We find that >50 per cent of black hole growth takes place at z > 1 , with around half in L_X < 10^(44) erg s^(\u22121) AGN.",
"doi": "10.1111/j.1365-2966.2009.15829.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2010-02",
"series_number": "4",
"volume": "401",
"issue": "4",
"pages": "2531-2551"
},
{
"id": "authors:46cfy-xc155",
"collection": "authors",
"collection_id": "46cfy-xc155",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091209-112844140",
"type": "article",
"title": "The SINS Survey: SINFONI Integral Field Spectroscopy of z ~ 2 Star-forming Galaxies",
"author": [
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Genzel",
"given_name": "R.",
"orcid": "0000-0002-2767-9653",
"clpid": "Genzel-Reinhard"
},
{
"family_name": "Bouch\u00e9",
"given_name": "N.",
"clpid": "Bouch\u00e9-N"
},
{
"family_name": "Cresci",
"given_name": "G.",
"clpid": "Cresci-G"
},
{
"family_name": "Davies",
"given_name": "R.",
"clpid": "Davies-R"
},
{
"family_name": "Buschkamp",
"given_name": "P.",
"clpid": "Buschkamp-P"
},
{
"family_name": "Shapiro",
"given_name": "K.",
"clpid": "Shapiro-K-L"
},
{
"family_name": "Tacconi",
"given_name": "L. J.",
"orcid": "0000-0002-1485-9401",
"clpid": "Tacconi-Linda-J"
},
{
"family_name": "Hicks",
"given_name": "E. K. S.",
"clpid": "Hicks-E-K-S"
},
{
"family_name": "Genel",
"given_name": "S.",
"orcid": "0000-0002-3185-1540",
"clpid": "Genel-S"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Erb",
"given_name": "D. K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Lutz",
"given_name": "D.",
"orcid": "0000-0003-0291-9582",
"clpid": "Lutz-Dieter"
},
{
"family_name": "Eisenhauer",
"given_name": "F.",
"clpid": "Eisenhauer-F"
},
{
"family_name": "Gillessen",
"given_name": "S.",
"clpid": "Gillessen-S"
},
{
"family_name": "Sternberg",
"given_name": "A.",
"clpid": "Sternberg-A"
},
{
"family_name": "Renzini",
"given_name": "A.",
"orcid": "0000-0002-7093-7355",
"clpid": "Renzini-A"
},
{
"family_name": "Cimatti",
"given_name": "A.",
"clpid": "Cimatti-A"
},
{
"family_name": "Daddi",
"given_name": "E.",
"orcid": "0000-0002-3331-9590",
"clpid": "Daddi-Emanuele"
},
{
"family_name": "Kurk",
"given_name": "J.",
"clpid": "Kurk-J"
},
{
"family_name": "Lilly",
"given_name": "S.",
"orcid": "0000-0002-6423-3597",
"clpid": "Lilly-S-J"
},
{
"family_name": "Kong",
"given_name": "X.",
"clpid": "Kong-X"
},
{
"family_name": "Lehnert",
"given_name": "M. D.",
"orcid": "0000-0003-1939-5885",
"clpid": "Lehnert-Matthew-D"
},
{
"family_name": "Nesvadba",
"given_name": "N.",
"clpid": "Nesvadba-N-P-H"
},
{
"family_name": "Verma",
"given_name": "A.",
"clpid": "Verma-A"
},
{
"family_name": "McCracken",
"given_name": "H.",
"orcid": "0000-0002-9489-7765",
"clpid": "McCracken-H-J"
},
{
"family_name": "Arimoto",
"given_name": "N.",
"clpid": "Arimoto-Nobuo"
},
{
"family_name": "Mignoli",
"given_name": "M.",
"clpid": "Mignoli-M"
},
{
"family_name": "Onodera",
"given_name": "M.",
"clpid": "Onodera-Masato"
}
],
"abstract": "We present the Spectroscopic Imaging survey in the near-infrared (near-IR) with SINFONI (SINS) of high-redshift galaxies. With 80 objects observed and 63 detected in at least one rest-frame optical nebular emission line, mainly H\u03b1, SINS represents the largest survey of spatially resolved gas kinematics, morphologies, and physical properties of star-forming galaxies at z ~ 1-3. We describe the selection of the targets, the observations, and the data reduction. We then focus on the \"SINS H\u03b1 sample,\" consisting of 62 rest-UV/optically selected sources at 1.3 < z < 2.6 for which we targeted primarily the H\u03b1 and [N II] emission lines. Only \u224830% of this sample had previous near-IR spectroscopic observations. The galaxies were drawn from various imaging surveys with different photometric criteria; as a whole, the SINS H\u03b1 sample covers a reasonable representation of massive M_* \u2273 10^(10) M_\u2609 star-forming galaxies at z \u2248 1.5-2.5, with some bias toward bluer systems compared to pure K-selected samples due to the requirement of secure optical redshift. The sample spans 2 orders of magnitude in stellar mass and in absolute and specific star formation rates, with median values \u22483 \u00d7 10^(10) M_\u2609, \u224870 M_\u2609 yr^(\u20131), and \u22483 Gyr^(\u20131). The ionized gas distribution and kinematics are spatially resolved on scales ranging from \u22481.5 kpc for adaptive optics assisted observations to typically \u22484-5 kpc for seeing-limited data. The H\u03b1 morphologies tend to be irregular and/or clumpy. About one-third of the SINS H\u03b1 sample galaxies are rotation-dominated yet turbulent disks, another one-third comprises compact and velocity dispersion-dominated objects, and the remaining galaxies are clear interacting/merging systems; the fraction of rotation-dominated systems increases among the more massive part of the sample. The H\u03b1 luminosities and equivalent widths suggest on average roughly twice higher dust attenuation toward the H II regions relative to the bulk of the stars, and comparable current and past-averaged star formation rates.",
"doi": "10.1088/0004-637X/706/2/1364",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2009-12-01",
"series_number": "2",
"volume": "706",
"issue": "2",
"pages": "1364-1428"
},
{
"id": "authors:fmsn3-7s057",
"collection": "authors",
"collection_id": "fmsn3-7s057",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090831-131328673",
"type": "article",
"title": "The SINS Survey: Broad Emission Lines in High-Redshift Star-Forming Galaxies",
"author": [
{
"family_name": "Shapiro",
"given_name": "Kristen L.",
"clpid": "Shapiro-K-L"
},
{
"family_name": "Genzel",
"given_name": "Reinhard",
"orcid": "0000-0002-2767-9653",
"clpid": "Genzel-Reinhard"
},
{
"family_name": "Quataert",
"given_name": "Eliot",
"orcid": "0000-0001-9185-5044",
"clpid": "Quataert-E"
},
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "Natascha M.",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Davies",
"given_name": "Richard",
"clpid": "Davies-R"
},
{
"family_name": "Tacconi",
"given_name": "Linda",
"orcid": "0000-0002-1485-9401",
"clpid": "Tacconi-Linda-J"
},
{
"family_name": "Armus",
"given_name": "Lee",
"orcid": "0000-0003-3498-2973",
"clpid": "Armus-L"
},
{
"family_name": "Bouch\u00e9",
"given_name": "Nicolas",
"clpid": "Bouch\u00e9-N"
},
{
"family_name": "Buschkamp",
"given_name": "Peter",
"clpid": "Buschkamp-P"
},
{
"family_name": "Cimatti",
"given_name": "Andrea",
"clpid": "Cimatti-A"
},
{
"family_name": "Cresci",
"given_name": "Giovanni",
"clpid": "Cresci-G"
},
{
"family_name": "Daddi",
"given_name": "Emanuele",
"orcid": "0000-0002-3331-9590",
"clpid": "Daddi-Emanuele"
},
{
"family_name": "Eisenhauer",
"given_name": "Frank",
"clpid": "Eisenhauer-F"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Genel",
"given_name": "Shy",
"orcid": "0000-0002-3185-1540",
"clpid": "Genel-S"
},
{
"family_name": "Hicks",
"given_name": "Erin K. S.",
"clpid": "Hicks-E-K-S"
},
{
"family_name": "Lilly",
"given_name": "Simon J.",
"orcid": "0000-0002-6423-3597",
"clpid": "Lilly-S-J"
},
{
"family_name": "Lutz",
"given_name": "Dieter",
"orcid": "0000-0003-0291-9582",
"clpid": "Lutz-Dieter"
},
{
"family_name": "Renzini",
"given_name": "Alvio",
"orcid": "0000-0002-7093-7355",
"clpid": "Renzini-A"
},
{
"family_name": "Shapley",
"given_name": "Alice",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Sternberg",
"given_name": "Amiel",
"clpid": "Sternberg-A"
}
],
"abstract": "High signal-to-noise, representative spectra of star-forming galaxies at z ~ 2, obtained via stacking, reveal a high-velocity component underneath the narrow H\u03b1 and [NII] emission lines. When modeled as a single Gaussian, this broad component has FWHM 1500 km s\u20131; when modeled as broad wings on the H\u03b1 and [N II] features, it has FWHM \u2273 500 km s^(\u20131). This feature is preferentially found in the more massive and more rapidly star-forming systems, which also tend to be older and larger galaxies. We interpret this emission as evidence of either powerful starburst-driven galactic winds or active supermassive black holes (SMBHs). If galactic winds are responsible for the broad emission, the observed luminosity and velocity of this gas imply mass outflow rates comparable to the star formation rate. On the other hand, if the broad-line regions of active black holes account for the broad feature, the corresponding black holes masses are estimated to be an order of magnitude lower than those predicted by local scaling relations, suggesting a delayed assembly of SMBHs with respect to their host bulges.",
"doi": "10.1088/0004-637X/701/2/955",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2009-08-20",
"series_number": "2",
"volume": "701",
"issue": "2",
"pages": "955-963"
},
{
"id": "authors:7dftj-fge90",
"collection": "authors",
"collection_id": "7dftj-fge90",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091002-133653002",
"type": "article",
"title": "The ultraviolet spectrum of the gravitationally lensed galaxy 'the Cosmic Horseshoe': a close-up of a star-forming galaxy at z\u223c 2",
"author": [
{
"family_name": "Quider",
"given_name": "Anna M.",
"clpid": "Quider-A-M"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "Taking advantage of strong gravitational lensing, we have recorded the rest-frame ultraviolet (UV) spectrum of the z= 2.38115 galaxy 'the Cosmic Horseshoe' (J1148+1930) at higher resolution and signal-to-noise ratio than is currently feasible for unlensed galaxies at z= 2\u20133 . With a star formation rate of ~100 M_\u2299 yr^(\u22121) , dynamical mass M_vir\u2243 1 \u00d7 10^(10) M_\u2299 , half-solar metallicity and moderate reddening E(B\u2212V) = 0.15 , the Cosmic Horseshoe is a good example of the population of galaxies responsible for most of the star formation activity at these redshifts.\nFrom the analysis of stellar spectral features we conclude that a continuous mode of star formation with a Salpeter slope for stars in the mass range 5\u2013100 M_\u2299 gives a good representation of the UV spectrum, ruling out significant departures from a 'standard' initial mass function. Generally, we find good agreement between the values of metallicity deduced from stellar and nebular tracers. Interstellar absorption is present over a velocity range \u0394v\u2243 1000 km s^(\u22121) , from \u2212800 to +250 km s^(\u22121) relative to the stars and their H ii regions, but we still lack a model relating the kinematic structure of the gas to its location within the galaxy. There is evidence to suggest that the outflowing interstellar gas is patchy, covering only \u223c60 per cent of the UV stellar continuum.\nThe Ly\u03b1 line shares many of the characteristics of the so-called Ly\u03b1 emitters; its double-peaked profile can be reproduced by models of Ly\u03b1 photons resonantly scattered by an expanding shell of gas and dust, with \u223c10\u201315 per cent of the photons escaping the galaxy. Many of the physical properties of the Cosmic Horseshoe are similar to those of the only other galaxy at z= 2\u20133 studied in comparable detail up to now: MS 1512\u2212cB58. The fact that these two galaxies have drastically different Ly\u03b1 lines may be due simply to orientation effects, or differences in the covering factor of outflowing gas, and cautions against classifying high-z galaxies only on the basis of spectral features, such as Ly\u03b1, whose appearance can be affected by a variety of different parameters.",
"doi": "10.1111/j.1365-2966.2009.15234.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2009-08-10",
"series_number": "3",
"volume": "398",
"issue": "3",
"pages": "1263-1278"
},
{
"id": "authors:sw86a-sz432",
"collection": "authors",
"collection_id": "sw86a-sz432",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090908-091007755",
"type": "article",
"title": "Dynamics of Galactic Disks and Mergers at z ~ 1.6: Spatially Resolved Spectroscopy with Keck Laser Guide Star Adaptive Optics",
"author": [
{
"family_name": "Wright",
"given_name": "Shelley A.",
"orcid": "0000-0003-1034-8054",
"clpid": "Wright-S-A"
},
{
"family_name": "Larkin",
"given_name": "James E.",
"orcid": "0000-0001-7687-3965",
"clpid": "Larkin-J-E"
},
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
}
],
"abstract": "We present 0\".2 resolution near-infrared integral field spectroscopy of H\u03b1 emission from six star-forming galaxies at z ~ 1.6 (a look-back time of ~9.6 Gyr). These observations were obtained with OSIRIS using the Keck Laser Guide Star Adaptive Optics system. All sources have a compact spatial extent of ~1\", with an average half-light radius of r_(1/2) = 2.9 kpc and an average dereddened star formation rate of 22 M\u2299 yr^(\u20131). Based on H\u03b1 kinematics we find that these six galaxies are dynamically distinguishable, and we classify them as either irregular/merger or disk candidate systems. We find three systems (HDF-BX1287, HDF-BX1315, and Q1623-BX491) with varying geometries and dynamical properties. Three galaxies (HDF-BMZ1299, Q2343-BX344, and Q2343-BM145) are well fitted by an inclined-disk model with low-velocity residuals (20 to 46 km s^(\u20131)). An average plateau velocity of \u03bd(p) = 185 km s^(\u20131) is achieved within 1.0 kpc. The majority of observed velocity dispersions (\u03c3 ~ 88 km s^(\u20131)) can be explained by the residual seeing halo, and are not intrinsic to our sources. However, one irregular and one disk candidate have high-velocity dispersions (\u03c3_(obs) \u2273 200 km s^(\u20131)) that cannot be solely explained by beam smearing. For two disk candidates, we detect [N II] emission and are able to map the [N II]/H\u03b1 ratio on kiloparsec scales. In both cases, [N II] emission is more concentrated than H\u03b1 emission (\u227e0\".2), and peak ratios are best explained by the presence of an active galactic nucleus (AGN). These are among the weakest known AGNs at high redshift; however their emission is strong enough to impact high-redshift metallicity studies that use nebular ratios. All disk candidates have likely to be completed only a few orbital periods, and if left unperturbed are excellent candidates to become present-day spiral galaxies.",
"doi": "10.1088/0004-637X/699/1/421",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2009-07-01",
"series_number": "1",
"volume": "699",
"issue": "1",
"pages": "421-440"
},
{
"id": "authors:cj044-gjk08",
"collection": "authors",
"collection_id": "cj044-gjk08",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090828-114836846",
"type": "article",
"title": "The Kiloparsec-scale Kinematics of High-redshift Star-forming Galaxies",
"author": [
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Larkin",
"given_name": "James E.",
"orcid": "0000-0001-7687-3965",
"clpid": "Larkin-J-E"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Wright",
"given_name": "Shelley A.",
"orcid": "0000-0003-1034-8054",
"clpid": "Wright-S-A"
}
],
"abstract": "We present the results of a spectroscopic survey of the kinematic structure of star-forming galaxies at redshift z ~ 2-3 using Keck/OSIRIS integral field spectroscopy. Our sample is comprised of 12 galaxies between redshifts z ~ 2.0 and 2.5 and one galaxy at z ~ 3.3 which are well detected in either H\u03b1 or [O III] emission. These galaxies are generally representative of the mean stellar mass of star-forming galaxies at similar redshifts, although they tend to have star formation rate surface densities slightly higher than the mean. These observations were obtained in conjunction with the Keck laser guide star adaptive optics system, with a typical angular resolution after spatial smoothing ~0\".15 (approximately 1 kpc at the redshift of the target sample). At most five of these 13 galaxies have spatially resolved velocity gradients consistent with rotation while the remaining galaxies have relatively featureless or irregular velocity fields. All of our galaxies show local velocity dispersions ~60-100 km s^(\u20131), suggesting that (particularly for those galaxies with featureless velocity fields) rotation about a preferred axis may not be the dominant mechanism of physical support. While some galaxies show evidence for major mergers such evidence is unrelated to the kinematics of individual components (one of our strongest merger candidates also exhibits unambiguous rotational structure), refuting a simple bimodal disk/merger classification scheme. We discuss these data in light of complementary surveys and extant UV-IR spectroscopy and photometry, concluding that the dynamical importance of cold gas may be the primary factor governing the observed kinematics of z ~ 2 galaxies. We conclude by speculating on the importance of mechanisms for accreting low angular momentum gas and the early formation of quasi-spheroidal systems in the young universe.",
"doi": "10.1088/0004-637X/697/2/2057",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2009-06-01",
"series_number": "2",
"volume": "697",
"issue": "2",
"pages": "2057-2082"
},
{
"id": "authors:37h2f-ww625",
"collection": "authors",
"collection_id": "37h2f-ww625",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091001-100336792",
"type": "article",
"title": "A Steep Faint-End Slope of the UV Luminosity Function at z ~ 2-3: Implications for the Global Stellar Mass Density and Star Formation in Low-Mass Halos",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We use the deep ground-based optical photometry of the Lyman Break Galaxy (LBG) Survey to derive robust measurements of the faint-end slope (\u03b1) of the UV luminosity function (LF) at redshifts 1.9 \u2264 z \u2264 3.4. Our sample includes >2000 spectroscopic redshifts and 31000 LBGs in 31 spatially independent fields over a total area of 3261 arcmin^2. These data allow us to select galaxies to 0.07L^* and 0.10L^* at z ~ 2 and z ~ 3, respectively. A maximum-likelihood analysis indicates steep values of \u03b1(z = 2) = \u20131.73 \u00b1 0.07 and \u03b1(z = 3) = \u20131.73 \u00b1 0.13. This result is robust to luminosity-dependent systematics in the Ly\u03b1 equivalent width and reddening distributions, and is similar to the steep values advocated at z 4, and implies that 93% of the unobscured UV luminosity density at z ~ 2-3 arises from sub-L^* galaxies. With a realistic luminosity-dependent reddening distribution, faint to moderately luminous galaxies account for 70% and 25% of the bolometric luminosity density and present-day stellar mass density, respectively, when integrated over 1.9 \u2264 z < 3.4. We find a factor of 8-9 increase in the star-formation rate density between z ~ 6 and z ~ 2, due to both a brightening of L^* and an increasing dust correction proceeding to lower redshifts. Combining the UV LF with stellar mass estimates suggests a relatively steep low-mass slope of the stellar mass function at high redshift. The previously observed discrepancy between the integral of the star-formation history and stellar mass density measurements at z ~ 2 may be reconciled by invoking a luminosity-dependent reddening correction to the star-formation history combined with an accounting for the stellar mass contributed by UV-faint galaxies. The steep and relatively constant faint-end slope of the UV LF at z 2 contrasts with the shallower slope inferred locally, suggesting that the evolution in the faint-end slope may be dictated simply by the availability of low-mass halos capable of supporting star formation at z 2.",
"doi": "10.1088/0004-637X/692/1/778",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2009-02-10",
"series_number": "1",
"volume": "692",
"issue": "1",
"pages": "778-803"
},
{
"id": "authors:jvmb0-bas71",
"collection": "authors",
"collection_id": "jvmb0-bas71",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:PETmnras08b",
"type": "article",
"title": "Deuterium abundance in the most metal-poor damped Lyman alpha system: converging on \u03a9b,0h^2",
"author": [
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Zych",
"given_name": "Berkeley J.",
"clpid": "Zych-B-J"
},
{
"family_name": "Murphy",
"given_name": "Michael T.",
"clpid": "Murphy-M-T"
},
{
"family_name": "Lewis",
"given_name": "Antony",
"clpid": "Lewis-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "The most metal-poor damped Ly\u03b1 system known to date, at zabs= 2.61843 in the spectrum of the QSO Q0913+072, with an oxygen abundance of only \u223c1/250 of the solar value, shows six well-resolved DI Lyman series transitions in high-quality echelle spectra recently obtained with the European Southern Observatory (ESO) VLT. We deduce a value of the deuterium abundance log (D/H) =\u22124.56 \u00b1 0.04 which is in good agreement with four out of the six most reliable previous determinations of this ratio in QSO absorbers. We find plausible reasons why in the other two cases the 1\u03c3 errors may have been underestimated by about a factor of two. The addition of this latest data point does not significantly change the mean value of the primordial abundance of deuterium, suggesting that we are now converging to a reliable measure of this quantity. We conclude that\u3008log (D/H)p\u3009=\u22124.55 \u00b1 0.03 and \u03a9b,0h2(BBN) = 0.0213 \u00b1 0.0010 (68 per cent confidence limits). Including the latter as a prior in the analysis of the Wilkinson Microwave Anisotropy Probe (WMAP) five-year data leads to a revised best-fitting value of the power-law index of primordial fluctuations ns= 0.956 \u00b1 0.013 (1\u03c3) and ns < 0.990 with 99 per cent confidence. Considering together the constraints provided by WMAP 5, (D/H)p, baryon oscillations in the galaxy distribution, and distances to Type Ia supernovae, we arrive at the current best estimates \u03a9b,0h2= 0.0224 \u00b1 0.0005 and ns= 0.959 \u00b1 0.013.",
"doi": "10.1111/j.1365-2966.2008.13921.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2008-12-21",
"series_number": "4",
"volume": "391",
"issue": "4",
"pages": "1499-1510"
},
{
"id": "authors:kzjzy-fh293",
"collection": "authors",
"collection_id": "kzjzy-fh293",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090524-210427908",
"type": "article",
"title": "From Rings to Bulges: Evidence for Rapid Secular Galaxy Evolution at z ~ 2 from Integral Field Spectroscopy in the SINS Survey",
"author": [
{
"family_name": "Genzel",
"given_name": "R.",
"orcid": "0000-0002-2767-9653",
"clpid": "Genzel-Reinhard"
},
{
"family_name": "Burkert",
"given_name": "A.",
"clpid": "Burkert-A"
},
{
"family_name": "Bouch\u00e9",
"given_name": "N.",
"clpid": "Bouch\u00e9-N"
},
{
"family_name": "Cresci",
"given_name": "G.",
"clpid": "Cresci-G"
},
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Shapley",
"given_name": "A.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Shapiro",
"given_name": "K.",
"clpid": "Shapiro-K-L"
},
{
"family_name": "Tacconi",
"given_name": "L. J.",
"orcid": "0000-0002-1485-9401",
"clpid": "Tacconi-Linda-J"
},
{
"family_name": "Buschkamp",
"given_name": "P.",
"clpid": "Buschkamp-P"
},
{
"family_name": "Cimatti",
"given_name": "A.",
"clpid": "Cimatti-A"
},
{
"family_name": "Daddi",
"given_name": "E.",
"orcid": "0000-0002-3331-9590",
"clpid": "Daddi-Emanuele"
},
{
"family_name": "Davies",
"given_name": "R.",
"clpid": "Davies-R"
},
{
"family_name": "Eisenhauer",
"given_name": "F.",
"clpid": "Eisenhauer-F"
},
{
"family_name": "Erb",
"given_name": "D. K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Genel",
"given_name": "S.",
"orcid": "0000-0002-3185-1540",
"clpid": "Genel-S"
},
{
"family_name": "Gerhard",
"given_name": "O.",
"clpid": "Gerhard-O"
},
{
"family_name": "Hicks",
"given_name": "E.",
"clpid": "Hicks-E-K-S"
},
{
"family_name": "Lutz",
"given_name": "D.",
"orcid": "0000-0003-0291-9582",
"clpid": "Lutz-Dieter"
},
{
"family_name": "Naab",
"given_name": "T.",
"clpid": "Naab-T"
},
{
"family_name": "Ott",
"given_name": "T.",
"clpid": "Ott-T"
},
{
"family_name": "Rabien",
"given_name": "S.",
"clpid": "Rabien-S"
},
{
"family_name": "Renzini",
"given_name": "A.",
"orcid": "0000-0002-7093-7355",
"clpid": "Renzini-A"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Sternberg",
"given_name": "A.",
"clpid": "Sternberg-A"
},
{
"family_name": "Lilly",
"given_name": "S. J.",
"orcid": "0000-0002-6423-3597",
"clpid": "Lilly-S-J"
}
],
"abstract": "We present H\u03b1 integral field spectroscopy of well-resolved, UV/optically selected z ~ 2 star-forming galaxies as part of the SINS survey with SINFONI on the ESO VLT. Our laser guide star adaptive optics and good seeing data show the presence of turbulent rotating star-forming outer rings/disks, plus central bulge/inner disk components, whose mass fractions relative to the total dynamical mass appear to scale with the [N II]/H\u03b1 flux ratio and the star formation age. We propose that the buildup of the central disks and bulges of massive galaxies at z ~ 2 can be driven by the early secular evolution of gas-rich proto-disks. High-redshift disks exhibit large random motions. This turbulence may in part be stirred up by the release of gravitational energy in the rapid \"cold\" accretion flows along the filaments of the cosmic web. As a result, dynamical friction and viscous processes proceed on a timescale of <1 Gyr, at least an order of magnitude faster than in z ~ 0 disk galaxies. Early secular evolution thus drives gas and stars into the central regions and can build up exponential disks and massive bulges, even without major mergers. Secular evolution along with increased efficiency of star formation at high surface densities may also help to account for the short timescales of the stellar buildup observed in massive galaxies at z ~ 2.",
"doi": "10.1086/591840",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2008-11-01",
"series_number": "1",
"volume": "687",
"issue": "1",
"pages": "59-77"
},
{
"id": "authors:pedw3-vxt86",
"collection": "authors",
"collection_id": "pedw3-vxt86",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090428-075610786",
"type": "article",
"title": "Kinemetry of SINS high-redshift star-forming galaxies : distinguishing rotating disks from major mergers",
"author": [
{
"family_name": "Shapiro",
"given_name": "Kristen L.",
"clpid": "Shapiro-K-L"
},
{
"family_name": "Genzel",
"given_name": "Reinhard",
"orcid": "0000-0002-2767-9653",
"clpid": "Genzel-Reinhard"
},
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "Natascha M.",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Tacconi",
"given_name": "Linda J.",
"orcid": "0000-0002-1485-9401",
"clpid": "Tacconi-Linda-J"
},
{
"family_name": "Bouch\u00e9",
"given_name": "Nicolas",
"clpid": "Bouch\u00e9-N"
},
{
"family_name": "Cresci",
"given_name": "Giovanni",
"clpid": "Cresci-G"
},
{
"family_name": "Davies",
"given_name": "Richard",
"clpid": "Davies-R"
},
{
"family_name": "Eisenhauer",
"given_name": "Frank",
"clpid": "Eisenhauer-F"
},
{
"family_name": "Johansson",
"given_name": "Peter H.",
"clpid": "Johansson-P-H"
},
{
"family_name": "Krajnovi\u0107",
"given_name": "Davor",
"clpid": "Krajnovi\u0107-D"
},
{
"family_name": "Lutz",
"given_name": "Dieter",
"orcid": "0000-0003-0291-9582",
"clpid": "Lutz-Dieter"
},
{
"family_name": "Naab",
"given_name": "Thorsten",
"clpid": "Naab-T"
},
{
"family_name": "Arimoto",
"given_name": "Nobuo",
"clpid": "Arimoto-Nobuo"
},
{
"family_name": "Arribas",
"given_name": "Santiago",
"orcid": "0000-0001-7997-1640",
"clpid": "Arribas-S"
},
{
"family_name": "Cimatti",
"given_name": "Andrea",
"clpid": "Cimatti-A"
},
{
"family_name": "Colina",
"given_name": "Luis",
"orcid": "0000-0002-9090-4227",
"clpid": "Colina-L"
},
{
"family_name": "Daddi",
"given_name": "Emanuele",
"orcid": "0000-0002-3331-9590",
"clpid": "Daddi-Emanuele"
},
{
"family_name": "Daigle",
"given_name": "Olivier",
"clpid": "Daigle-O"
},
{
"family_name": "Erb",
"given_name": "Dawn",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Hernandez",
"given_name": "Olivier",
"clpid": "Hernandez-O"
},
{
"family_name": "Kong",
"given_name": "Xu",
"clpid": "Kong-Xu"
},
{
"family_name": "Mignoli",
"given_name": "Marco",
"clpid": "Mignoli-M"
},
{
"family_name": "Onodera",
"given_name": "Masato",
"clpid": "Onodera-Masato"
},
{
"family_name": "Renzini",
"given_name": "Alvio",
"orcid": "0000-0002-7093-7355",
"clpid": "Renzini-A"
},
{
"family_name": "Shapley",
"given_name": "Alice",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present a simple set of kinematic criteria that can distinguish between galaxies dominated by ordered rotational motion and those involved in major merger events. Our criteria are based on the dynamics of the warm ionized gas (as traced by H\u03b1) within galaxies, making this analysis accessible to high-redshift systems, whose kinematics are primarily traceable through emission features. Using the method of kinemetry (developed by Krajnovi\u0107 and coworkers), we quantify asymmetries in both the velocity and velocity dispersion maps of the warm gas, and the resulting criteria enable us to empirically differentiate between nonmerging and merging systems at high redshift. We apply these criteria to 11 of our best-studied rest-frame UV/optical-selected z ~ 2 galaxies for which we have near-infrared integral-field spectroscopic data from SINFONI on the VLT. Of these 11 systems, we find that >50% have kinematics consistent with a single rotating disk interpretation, while the remaining systems are more likely undergoing major mergers. This result, combined with the short formation timescales of these systems, provides evidence that rapid, smooth accretion of gas plays a significant role in galaxy formation at high redshift.",
"doi": "10.1086/587133",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2008-07-20",
"series_number": "1",
"volume": "682",
"issue": "1",
"pages": "231-251"
},
{
"id": "authors:pat5g-nv881",
"collection": "authors",
"collection_id": "pat5g-nv881",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090519-090047352",
"type": "article",
"title": "C, N, O abundances in the most metal-poor damped Lyman alpha systems",
"author": [
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Zych",
"given_name": "Berkeley J.",
"clpid": "Zych-B-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Chaffee",
"given_name": "Fred H.",
"clpid": "Chaffee-F-H"
}
],
"abstract": "This study focuses on some of the most metal-poor damped Ly\u03b1 (DLA) absorbers known in the spectra of high-redshift QSOs, using new and archival observations obtained with ultraviolet-sensitive echelle spectrographs on the Keck and VLT telescopes. The weakness and simple velocity structure of the absorption lines in these systems allow us to measure the abundances of several elements, and in particular those of C, N and O, a group that is difficult to study in DLAs of more typical metallicities. We find that when the oxygen abundance is less than \u223c1/100 of solar, the C/O ratio in high-redshift DLAs and sub-DLAs matches that of halo stars of similar metallicity and shows higher values than expected from galactic chemical evolution models based on conventional stellar yields. Furthermore, there are indications that at these low metallicities the N/O ratio may also be above simple expectations and may exhibit a minimum value, as proposed by Centuri\u00f3n and her collaborators in 2003. Both results can be interpreted as evidence for enhanced production of C and N by massive stars in the first few episodes of star formation, in our Galaxy and in the distant protogalaxies seen as QSO absorbers. The higher stellar yields implied may have an origin in stellar rotation which promotes mixing in the stars' interiors, as considered in some recent model calculations. We briefly discuss the relevance of these results to current ideas on the origin of metals in the intergalactic medium and the universality of the stellar initial mass function.",
"doi": "10.1111/j.1365-2966.2008.12951.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2008-04-21",
"series_number": "4",
"volume": "385",
"issue": "4",
"pages": "2011-2024"
},
{
"id": "authors:trfg0-asz89",
"collection": "authors",
"collection_id": "trfg0-asz89",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:GONapj08",
"type": "article",
"title": "Detection of the transverse proximity effect : radiative feedback from bright QSOs",
"author": [
{
"family_name": "Gon\u00e7alves",
"given_name": "Thiago S.",
"clpid": "Gon\u00e7alves-T-S"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "Measuring the response of the intergalactic medium (IGM) to a blast of ionizing radiation allows one to infer the physical properties of the medium and, in principle, the lifetime and isotropy of the radiating source. The most sensitive such measurements can be made if the source of radiation is near the line of sight to a bright background QSO. We present results based on deep Keck HIRES observations of the QSO triplet KP 76, KP 77, and KP 78 at z \u2243 2.5, with separations of 2'-3' on the plane of the sky. Using accurate systemic redshifts of the QSOs from near-IR spectroscopy, we quantify the state of the IGM gas in the proximity regions where the expected ionizing flux from the foreground QSOs exceeds that of the metagalactic background by factors of 10-200, assuming constant and isotropic emission. Based on the unusual ionization properties of the absorption systems with detected H I, C IV, and O VI, we conclude that the gas has been significantly affected by the UV radiation from the nearby QSOs. Aided by observations of the galaxy density near the foreground QSOs, we discuss several effects that may explain why the transverse proximity effect has eluded most previous attempts to detect it. Our observations suggest that the luminosities of KP 76 and KP 77 have remained comparable to current values over timescales of, respectively, \u0394 t > 25 Myr and 16 Myr < \u0394 t < 33 Myr , consistent with typical QSO lifetimes estimated from independent, less direct methods. There is no evidence that the UV radiation from either QSO was significantly anisotropic during these intervals.",
"doi": "10.1086/527313",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2008-04-01",
"series_number": "2",
"volume": "676",
"issue": "2",
"pages": "816-835"
},
{
"id": "authors:gey18-cap65",
"collection": "authors",
"collection_id": "gey18-cap65",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090527-080644843",
"type": "article",
"title": "Multiwavelength constraints on the cosmic star formation history from spectroscopy: the rest-frame ultraviolet, H\u03b1, and infrared luminosity functions at redshifts 1.9 \u227e z \u227e 3.4",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Dickinson",
"given_name": "Mark",
"orcid": "0000-0001-5414-5131",
"clpid": "Dickinson-Mark-E"
}
],
"abstract": "We use a sample of rest-frame UV-selected and spectroscopically observed galaxies at redshifts 1.9 \u2264 z < 3.4, combined with ground-based spectroscopic H\u03b1 and Spitzer MIPS 24 \u03bcm data, to derive the most robust measurements of the rest-frame UV, H\u03b1, and infrared (IR) luminosity functions (LFs) at these redshifts. Our sample is by far the largest of its kind, with over 2000 spectroscopic redshifts in the range 1.9 \u2264 z < 3.4 and ~15,000 photometric candidates in 29 independent fields covering a total area of almost a square degree. Our method for computing the LFs takes into account a number of systematic effects, including photometric scatter, Ly\u03b1 line perturbations to the observed optical colors of galaxies, and contaminants. Taking into account the latter, we find no evidence for an excess of UV-bright galaxies over what was inferred in early z ~ 3 LBG studies. The UV LF appears to undergo little evolution between z ~ 4 and z ~ 2. Corrected for extinction, the UV luminosity density (LD) at z ~ 2 is at least as large as the value at z ~ 3 and a factor of ~9 larger than the value at z ~ 6, primarily reflecting an increase in the number density of bright galaxies between z ~ 6 and z ~ 2. Our analysis yields the first constraints anchored by extensive spectroscopy on the infrared and bolometric LFs for faint and moderately luminous (L_(bol) \u227e 10^(12) L\u2299) galaxies. Adding the IR to the emergent UV luminosity, incorporating independent measurements of the LD from ULIRGs, and assuming realistic dust attenuation values for UV-faint galaxies, indicates that galaxies with L_(bol) < 10^(12) L\u2299 account for \u224880% of the bolometric LD and SFRD at z ~ 2\u20133. This suggests that previous estimates of the faint end of the Lbol LF may have underestimated the steepness of the faint-end slope at L_(bol) < 10^(12) L\u2299. Our multiwavelength constraints on the global SFRD indicate that approximately one-third of the present-day stellar mass density was formed in subultraluminous galaxies between redshifts z = 1.9\u20133.4.",
"doi": "10.1086/521105",
"issn": "0067-0049",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Supplement Series",
"publication_date": "2008-03",
"series_number": "1",
"volume": "175",
"issue": "1",
"pages": "48-85"
},
{
"id": "authors:3sqrq-nw049",
"collection": "authors",
"collection_id": "3sqrq-nw049",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:KACaj08",
"type": "article",
"title": "Halo gas cross sections and covering fractions of MgII absorption selected galaxies",
"author": [
{
"family_name": "Kacprzak",
"given_name": "Glenn G.",
"clpid": "Kacprzak-G-G"
},
{
"family_name": "Churchill",
"given_name": "Christopher W.",
"clpid": "Churchill-C-W"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Murphy",
"given_name": "Michael T.",
"clpid": "Murphy-M-T"
}
],
"abstract": "We examine halo gas cross sections and covering fractions, fc, of intermediate-redshift Mg II absorption selected galaxies. We computed statistical absorber halo radii, Rx, using current values of dN/dz and Schechter luminosity function parameters, and have compared these values to the distribution of impact parameters and luminosities from a sample of 37 galaxies. For equivalent widths Wr(2796) \u2265 0.3 \u00c5, we find 43 \u2264 Rx \u2264 88 kpc, depending on the lower luminosity cutoff and the slope, \u03b2, of the Holmberg-like luminosity scaling, R \u221d \u03b1 L^\u03b2 . The observed distribution of impact parameters, D, are such that several absorbing galaxies lie at D > Rx and several non-absorbing galaxies lie at D < Rx. We deduced that fc must be less than unity and obtain a mean of ~ 0.5 for our sample. Moreover, the data suggest that halo radii of Mg II absorbing galaxies do not follow a luminosity scaling with \u03b2 in the range of 0.2\u20130.28, if fc = 1 as previously reported. However, provided fc ~ 0.5, we find that halo radii can remain consistent with a Holmberg-like luminosity relation with \u03b2 \u2243 0.2 and R\u2217 = Rx/\u221a(fc) ~ 110 kpc. No luminosity scaling (\u03b2 = 0) is also consistent with the observed distribution of impact parameters if fc \u2264 0.37. The data support a scenario in which gaseous halos are patchy and likely have non-symmetric geometric distributions about the galaxies. We suggest that halo gas distributions may not be governed primarily by galaxy mass/luminosity but also by stochastic processes local to the galaxy.",
"doi": "10.1088/0004-6256/135/3/922",
"issn": "0004-6256",
"publisher": "University of Chicago Press",
"publication": "Astronomical Journal",
"publication_date": "2008-03",
"series_number": "3",
"volume": "135",
"issue": "3",
"pages": "922-927"
},
{
"id": "authors:dpev3-4df48",
"collection": "authors",
"collection_id": "dpev3-4df48",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091029-090949441",
"type": "article",
"title": "Dynamical Properties of z ~ 2 Star-forming Galaxies and a Universal Star Formation Relation",
"author": [
{
"family_name": "Bouch\u00e9",
"given_name": "N.",
"clpid": "Bouch\u00e9-N"
},
{
"family_name": "Cresci",
"given_name": "G.",
"clpid": "Cresci-G"
},
{
"family_name": "Davies",
"given_name": "R.",
"clpid": "Davies-R"
},
{
"family_name": "Eisenhauer",
"given_name": "F.",
"clpid": "Eisenhauer-F"
},
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Genzel",
"given_name": "R.",
"orcid": "0000-0002-2767-9653",
"clpid": "Genzel-Reinhard"
},
{
"family_name": "Gillessen",
"given_name": "S.",
"clpid": "Gillessen-S"
},
{
"family_name": "Lehnert",
"given_name": "M.",
"orcid": "0000-0003-1939-5885",
"clpid": "Lehnert-Matthew-D"
},
{
"family_name": "Lutz",
"given_name": "D.",
"orcid": "0000-0003-0291-9582",
"clpid": "Lutz-Dieter"
},
{
"family_name": "Nesvadba",
"given_name": "N.",
"clpid": "Nesvadba-N-P-H"
},
{
"family_name": "Shapiro",
"given_name": "K. L.",
"clpid": "Shapiro-K-L"
},
{
"family_name": "Sternberg",
"given_name": "A.",
"clpid": "Sternberg-A"
},
{
"family_name": "Tacconi",
"given_name": "L. J.",
"orcid": "0000-0002-1485-9401",
"clpid": "Tacconi-Linda-J"
},
{
"family_name": "Verma",
"given_name": "A.",
"clpid": "Verma-A"
},
{
"family_name": "Cimatti",
"given_name": "A.",
"clpid": "Cimatti-A"
},
{
"family_name": "Daddi",
"given_name": "E.",
"orcid": "0000-0002-3331-9590",
"clpid": "Daddi-Emanuele"
},
{
"family_name": "Renzini",
"given_name": "A.",
"orcid": "0000-0002-7093-7355",
"clpid": "Renzini-A"
},
{
"family_name": "Erb",
"given_name": "D. K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Shapley",
"given_name": "A.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present the first comparison of the dynamical properties of different samples of z ~ 1.4-3.4 star-forming galaxies from spatially resolved imaging spectroscopy from SINFONI/VLT integral field spectroscopy and IRAM CO millimeter interferometry. Our samples include 16 rest-frame UV-selected, 16 rest-frame optically selected, and 13 submillimeter galaxies (SMGs). We find that rest-frame UV and optically bright (K < 20) z ~ 2 star forming galaxies are dynamically similar, and follow the same velocity-size relation as disk galaxies at z ~ 0. In the theoretical framework of rotating disks forming from dissipative collapse in dark matter halos, the two samples require a spin parameter <\u03bb> ranging from 0.06 to 0.2. In contrast, bright SMGs (S_(850) \u03bcm \u2265 5 mJy) have larger velocity widths and are much more compact. Hence, SMGs have lower angular momenta and higher matter densities than either the UV or optically selected populations. This indicates that dissipative major mergers may dominate the SMGs population, resulting in early spheroids, and that a significant fraction of the UV/optically bright galaxies have evolved less violently, either in a series of minor mergers, or in rapid dissipative collapse from the halo, given that either process may leads to the formation of early disks. These early disks may later evolve into spheroids via disk instabilities or mergers. Because of their small sizes and large densities, SMGs lie at the high surface density end of a universal (out to z = 2.5) \"Schmidt-Kennicutt\" relation between gas surface density and star formation rate surface density. The best-fit relation suggests that the star formation rate per unit area scales as the surface gas density to a power of ~1.7, and that the star formation efficiency increases by a factor of 4 between non-starbursts and strong starbursts.",
"doi": "10.1086/522221",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2007-12-10",
"series_number": "1",
"volume": "671",
"issue": "1",
"pages": "303-309"
},
{
"id": "authors:4k4pc-tny67",
"collection": "authors",
"collection_id": "4k4pc-tny67",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091109-143310813",
"type": "article",
"title": "The Sightline to Q2343-BX415: Clues to Galaxy Formation in a Quasar Environment",
"author": [
{
"family_name": "Rix",
"given_name": "Samantha A.",
"clpid": "Rix-Samantha-A"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
}
],
"abstract": "We have discovered a strong DLA coincident in redshift with the faint QSO Q2343-BX415 (R = 20.2, z_(em) = 2.57393). Follow-up observations at intermediate spectral resolution reveal that the metal lines associated with this proximate DLA (PDLA) consist of two sets of absorption components. One set is moving toward the quasar with velocities of ~150-600 km s^(-1); this gas is highly ionized and does not fully cover the continuum source, suggesting that it is physically close to the active nucleus. The other, which accounts for most of the neutral gas, is blueshifted relative to the QSO, with the strongest component at ~-160 km s^(-1). We consider the possibility that the PDLA arises in the outflowing interstellar medium of the host galaxy of Q2343-BX415, an interpretation supported by strong C IV and N V absorption at nearby velocities, and by the intense radiation field longward of the Lyman limit implied by the high C II*/H I ratio. If Q2343-BX415 is the main source of these UV photons, then the PDLA is located at either ~8 or ~37 kpc from the active nucleus. Alternatively, the absorber may be a foreground star-forming galaxy unrelated to the quasar and coincidentally at the same redshift, but our deep imaging and follow-up spectroscopy of the field of Q2343-BX415 has not yet produced a likely candidate. We measure the abundances of 14 elements in the PDLA, finding an overall metallicity of ~1/5 solar and a normal pattern of relative element abundances for this metallicity. Thus, in this PDLA there is no evidence for the supersolar metallicities that have been claimed for some proximate, high-ionization, systems.",
"doi": "10.1086/521808",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2007-11-20",
"series_number": "1",
"volume": "670",
"issue": "1",
"pages": "15-38"
},
{
"id": "authors:kkw2e-dh068",
"collection": "authors",
"collection_id": "kkw2e-dh068",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:LAWapj07b",
"type": "article",
"title": "Integral field spectroscopy of high-redshift star-forming galaxies with laser-guided adaptive optics: Evidence for dispersion-dominated kinematics",
"author": [
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Larkin",
"given_name": "James E.",
"orcid": "0000-0001-7687-3965",
"clpid": "Larkin-J-E"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Wright",
"given_name": "Shelley A.",
"orcid": "0000-0003-1034-8054",
"clpid": "Wright-S-A"
}
],
"abstract": "We present early results from an ongoing study of the kinematic structure of star-forming galaxies at redshift z similar to 2-3 using integral-field spectroscopy of rest-frame optical nebular emission lines in combination with Keck laser guide star adaptive optics (LGSAO). We show kinematic maps of three target galaxies Q1623-BX453, Q0449-BX93, and DSF 2237a-C2 located at redshifts z = 2.1820, 2.0067, and 3.3172, respectively, each of which is well resolved with a PSF measuring approximately 0.11\"-0.15\" (similar to 900-1200 pc at z similar to 2-3) after cosmetic smoothing. Neither galaxy at z similar to 2 exhibits substantial kinematic structure on scales greater than or similar to 30 km s^(-1); both are instead consistent with largely dispersion-dominated velocity fields with sigma similar to 80 km s^(-1) along any given line of sight into the galaxy. In contrast, DSF 2237a-C2 presents a well-resolved gradient in velocity over a distance of similar to 4 kpc with peak-to-peak amplitude of 140 km s(-1). It is unlikely that DSF 2237a-C2 represents a dynamically cold rotating disk of ionized gas as the local velocity dispersion of the galaxy (sigma = 79 km s^(-1))is comparable to the observed shear. While some gas cooling models reproduce the observed kinematics better than a simple rotating disk model, even these provide a poor overall description of the target galaxies, suggesting that our current understanding of gas cooling mechanisms in galaxies in the early universe is (at best) incomplete.",
"doi": "10.1086/521786",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2007-11-10",
"series_number": "2",
"volume": "669",
"issue": "2",
"pages": "929-946"
},
{
"id": "authors:svcsk-bkt64",
"collection": "authors",
"collection_id": "svcsk-bkt64",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:PETapj07",
"type": "article",
"title": "Morphologies of Galaxies in and around a Protocluster at z = 2.300",
"author": [
{
"family_name": "Peter",
"given_name": "Annika H. G.",
"orcid": "0000-0002-8040-6785",
"clpid": "Peter-A-H-G"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "We present results from the first robust investigation of galaxy morphology as a function of environment at z > 1.5. Our study is motivated by the fact that star-forming galaxies contained within a protocluster at z = 2.3 in the HS 1700+64 field have significantly older ages and larger stellar masses on average than those at similar redshifts but more typical environmental densities. In the analysis of HST ACS images, we apply nonparametric statistics to characterize the rest-frame UV morphologies of a sample of 85 UV-selected star-forming galaxies at z = 1.7-2.9, 22 of which are contained in the protocluster. The remaining 63 control sample galaxies are not in the protocluster but have a similar mean redshift of zbar ~ 2.3. We find no environmental dependence for the distributions of morphological properties. Combining the measured morphologies with the results of population synthesis modeling, we find only weak correlations, if any, between morphological and stellar population properties such as stellar mass, age, extinction, and star formation rate. Given the incomplete census of the protocluster galaxy population, and the lack of correlation between rest-frame UV morphology and star formation history at z ~ 2 within our sample, the absence of environmental trends in the distribution of morphological properties is not surprising. In addition, using a larger sample of photometric candidates, we compare morphological distributions for 282 UV-selected and 43 near-IR-selected galaxies. While the difference in the degree of nebulosity between the two samples appears to be a by-product of the fainter average rest-frame UV surface brightness of the near-IR-selected galaxies, we find that, among the lowest surface brightness galaxies, the near-IR-selected objects have significantly smaller angular sizes.",
"doi": "10.1086/521184",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2007-10-10",
"series_number": "1",
"volume": "668",
"issue": "1",
"pages": "23-44"
},
{
"id": "authors:p12pg-0a536",
"collection": "authors",
"collection_id": "p12pg-0a536",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100429-113357034",
"type": "article",
"title": "On the Heterogeneity of Metal-Line and Ly\u03b1 Absorption in Galaxy \"Halos\" at z ~ 0.7",
"author": [
{
"family_name": "Churchill",
"given_name": "Christopher W.",
"clpid": "Churchill-C-W"
},
{
"family_name": "Kacprzak",
"given_name": "Glenn G.",
"clpid": "Kacprzak-G-G"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Evans",
"given_name": "Jessica L.",
"clpid": "Evans-J-L"
}
],
"abstract": "We examine the properties of two galaxy \"halos\" at z ~ 0.7 in the Ton 153 (z_(em) = 1.01) quasar field. The first absorber-galaxy pair (G1) is a z = 0.672, L_B = 4.3L*_B, E/S0 galaxy probed at D = 58 kpc. G1 is associated with a remarkable five-component Ly\u03b1 complex having \u03c4_(LL) \u2264 0.4, W_(r)(Ly\u03b1) = 2.8 \u00c5, and a velocity spread of \u0394v = 1420 km s^(-1). We find no Mg II, C IV, N V, nor O VI absorption in these clouds and infer metallicity upper limits of -3 \u2264 log Z/Z_\u2609 \u2264 -1, depending on assumptions of photoionized or collisionally ionized gas. The second absorber-galaxy pair (G2) is a z = 0.661, L_B = 1.8 L*_B, Sab galaxy probed at D = 103 kpc. G2 is associated with metal-enriched (log Z/Z_\u2609 \u2243 -0.4) photoionized gas having N(H I) \u2243 18.3 (cm^(-2)) and a velocity spread of \u0394v = 200 km s^(-1). The very different G1 and G2 systems both have gas-galaxy properties inconsistent with the standard luminosity-dependent galaxy \"halo\" model commonly invoked for quasar absorption line surveys. We emphasize that mounting evidence is revealing that extended galactic gaseous envelopes in the regime of D \u2264 100 kpc do not exhibit a level of homogeneity supporting a standardized halo model. Selection effects may have played a central role in the development of a simple model. We discuss the G1 and G2 systems in the context of \u039bCDM models of galaxy formation and suggest that the heterogeneous properties of absorber-galaxy pairs is likely related to the range of overdensities from which galaxies and gas structures arise.",
"doi": "10.1086/512113",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2007-06-01",
"series_number": "2",
"volume": "661",
"issue": "2",
"pages": "714-718"
},
{
"id": "authors:d2s23-kgz69",
"collection": "authors",
"collection_id": "d2s23-kgz69",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:LAWapj07",
"type": "article",
"title": "The physical nature of rest-UV galaxy morphology during the peak epoch of galaxy formation",
"author": [
{
"family_name": "Law",
"given_name": "David R.",
"orcid": "0000-0002-9402-186X",
"clpid": "Law-D-R"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Simenc",
"given_name": "David J.",
"clpid": "Simenc-David-J"
}
],
"abstract": "Motivated by the irregular and little-understood morphologies of z similar to 2-3 galaxies, we use nonparametric coefficients to quantify the morphologies of 216 galaxies that have been spectroscopically confirmed to lie at redshifts z = 1.8-3.4 in the GOODS-N field. Using measurements of UV and optical spectral lines, multiband photometric data, and stellar population models, we statistically assess possible correlations between galaxy morphology and physical observables such as stellar mass, star formation rate, and the strength of galaxy-scale outflows. We find evidence that dustier galaxies have more nebulous UV morphologies and that larger, more luminous galaxies may drive stronger outflows, but we otherwise conclude that UV morphology is either statistically decoupled from the majority of physical observables or determined by too complex a combination of physical processes to provide characterizations with predictive power. Given the absence of strong correlations between UV morphology and physical parameters such as star formation rates, we are therefore unable to support the hypothesis that morphologically irregular galaxies predominantly represent major galaxy mergers. Comparing galaxy samples, we find that IR-selected BzK galaxies and radio-selected submillimeter galaxies have UV morphologies similar to the optically selected sample, while distant red galaxies are more nebulous.",
"doi": "10.1086/510357",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2007-02-10",
"series_number": "1",
"volume": "656",
"issue": "1",
"pages": "1-26"
},
{
"id": "authors:mb1qc-49725",
"collection": "authors",
"collection_id": "mb1qc-49725",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110728-143023640",
"type": "article",
"title": "A Spectroscopic Survey of Redshift 1.4 \u227e z \u227e 3.0 Galaxies in the GOODS-North Field: Survey Description, Catalogs, and Properties",
"author": [
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
}
],
"abstract": "We present the results of a spectroscopic survey with LRIS-B on Keck of more than 280 star-forming galaxies and AGNs at redshifts 1.4 \u227e z \u227e 3.0 in the GOODS-N field. Candidates are selected by their U_nGR colors using the \"BM/BX\" criteria to target redshift 1.4 \u227e z \u227e 2.5 galaxies and the LBG criteria to target redshift z ~ 3 galaxies; combined these samples account for ~25%-30% of the R and K_s band counts to R = 25.5 and K_s(AB) = 24.4, respectively. The 212 BM/BX galaxies and 74 LBGs constitute the largest spectroscopic sample of galaxies at z > 1.4 in GOODS-N. Extensive multiwavelength data allow us to investigate the stellar populations, stellar masses, bolometric luminosities (L_(bol)), and extinction of z ~ 2 galaxies. Deep Chandra and Spitzer data indicate that the sample includes galaxies with a wide range in L_(bol) (\u224310^(10) to >10^(12) L_\u2609) and 4 orders of magnitude in dust obscuration (L_(bol)/L_(UV)). The sample includes galaxies with a large dynamic range in evolutionary state, from very young galaxies (ages \u224350 Myr) with small stellar masses (M* \u2243 10^9 M_\u2609) to evolved galaxies with stellar masses comparable to the most massive galaxies at these redshifts (M* > 10^(11) M_\u2609). Spitzer data indicate that the optical sample includes some fraction of the obscured AGN population at high redshifts: at least 3 of 11 AGNs in the z > 1.4 sample are undetected in the deep X-ray data but exhibit power-law SEDs longward of ~2 \u03bcm (rest frame) indicative of obscured AGNs. The results of our survey indicate that rest-frame UV selection and spectroscopy presently constitute the most timewise efficient method of culling large samples of high-redshift galaxies with a wide range in intrinsic properties, and the data presented here will add significantly to the multiwavelength legacy of GOODS.",
"doi": "10.1086/508851",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2006-12-20",
"series_number": "2",
"volume": "653",
"issue": "2",
"pages": "1004-1026"
},
{
"id": "authors:2nfhb-fq227",
"collection": "authors",
"collection_id": "2nfhb-fq227",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:LAImnras06",
"type": "article",
"title": "The X-ray emission of Lyman break galaxies",
"author": [
{
"family_name": "Laird",
"given_name": "E. S.",
"clpid": "Laird-E-S"
},
{
"family_name": "Nandra",
"given_name": "K.",
"orcid": "0000-0002-7150-9192",
"clpid": "Nandra-K"
},
{
"family_name": "Hobbs",
"given_name": "A.",
"clpid": "Hobbs-A"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We present an analysis of the X-ray emission of a large sample of z\u223c3 Lyman break galaxies (LBGs), based on Chandra/ACIS observations of several LBG survey fields. A total of 24 LBGs are directly detected in the X-ray, approximately doubling the number of known detections. Thirteen of the LBGs have optical spectroscopic signatures of active galactic nucleus (AGN) activity, but almost all the other X-ray detections are also likely to host an accreting black hole based on their X-ray properties. The AGN exhibit a wide range in X-ray luminosity, from weak Seyferts to bright quasi-stellar objects (QSOs). An optical spectroscopy identified approximately one-third of the X-ray-detected sources as broad-line QSOs, one-third as narrow-line AGN (NLAGN) and one-third as normal star-forming LBGs. The fraction of X-ray-detected LBGs is 3 per cent, much lower than that which has been found for submillimetre-selected galaxies. Two galaxies have X-ray luminosities, spectra and fX/fopt values that are consistent with emission from star formation processes and are identified as candidate X-ray bright, pure starburst galaxies at z\u223c 3. If powered solely by star formation, the sources would have star formation rates (SFRs) of 300\u2013500 M\u2299 yr\u22121. X-ray spectral analysis of the LBGs shows a mean photon index of \u0393= 1.96 , similar to local AGN. There is evidence for absorption in at least 40 per cent of the objects. Significantly more absorption is evident in the NLAGN, which is consistent with AGN unification schemes. After correction for absorption, the narrow- and broad-line objects show the same average luminosity. X-ray-detected LBGs, spectroscopically classified as normal galaxies, however, are less luminous in both soft and hard X-ray bands, indicating that the host galaxy is outshining any optical AGN signature. Turning to the X-ray emission from LBGs without direct detections, stacking the X-ray flux in the two deepest Chandra fields under consideration [the Hubble Deep Field-North (HDF-N) and Groth\u2013Westphal Strip (GWS)] produced significant detections in each, although the GWS result was marginal. The detection in the HDF-N gives an X-ray-derived SFR of 42.4 \u00b1 7.8 M\u2299 yr^\u22121 per LBG and, by comparing with the ultraviolet (UV) SFR, the implied UV extinction correction is 4.1 \u00b1 0.8. The LBG sample was split into three bins based on UV magnitude to examine the correlation between UV and X-ray emission: for the limited statistics available, there was no evidence of any correlation.",
"doi": "10.1111/j.1365-2966.2006.11002.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2006-11-21",
"series_number": "1",
"volume": "373",
"issue": "1",
"pages": "217-230"
},
{
"id": "authors:z2pja-cem57",
"collection": "authors",
"collection_id": "z2pja-cem57",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110727-154144547",
"type": "article",
"title": "The Direct Detection of Lyman Continuum Emission from Star-forming Galaxies at z~3",
"author": [
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
}
],
"abstract": "We present the results of rest-frame UV spectroscopic observations of a sample of 14 z ~ 3 star-forming galaxies in the SSA 22a field. These spectra are characterized by unprecedented depth in the Lyman continuum region. For the first time, we have detected escaping ionizing radiation from individual galaxies at high redshift, with 2 of the 14 objects showing significant emission below the Lyman limit. We also measured the ratio of emergent flux density at 1500 \u00c5 to that in the Lyman continuum region, for the individual detections (C49 and D3) and the sample average. If a correction for the average IGM opacity is applied to the spectra of the objects C49 and D3, we find f_(1500)/f_(900,corr,C49) = 4.5 and f_(1500)/f_(900,corr,D3) = 2.9. The average emergent flux density ratio in our sample is = 22, implying an escape fraction ~4.5 times lower than inferred from the composite spectrum from Steidel and coworkers. If this new estimate is representative of LBGs, their contribution to the metagalactic ionizing radiation field is J_\u03bd(900) ~ 2.6 \u00d7 10^(-22) ergs s^(-1) cm^(-2) Hz^(-1) sr^(-1), comparable to the contribution of optically selected quasars at the same redshift. The sum of the contributions from galaxies and quasars is consistent with recent estimates of the level of the ionizing background at z ~ 3, inferred from the H I Ly\u03b1 forest optical depth. There is significant variance among the emergent far-UV spectra in our sample, yet the factors controlling the detection or nondetection of Lyman continuum emission from galaxies are not well determined. Because we do not yet understand the source of this variance, significantly larger samples will be required to obtain robust constraints on the galaxy contribution to the ionizing background at z ~ 3 and beyond.",
"doi": "10.1086/507511",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2006-11-10",
"series_number": "2",
"volume": "651",
"issue": "2",
"pages": "688-703"
},
{
"id": "authors:x7bnm-4de65",
"collection": "authors",
"collection_id": "x7bnm-4de65",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110513-112624137",
"type": "article",
"title": "A deep Chandra survey of the Groth Strip \u2013 II. Optical identification of the X-ray sources",
"author": [
{
"family_name": "Georgakakis",
"given_name": "A.",
"clpid": "Georgakakis-A"
},
{
"family_name": "Nandra",
"given_name": "K.",
"orcid": "0000-0002-7150-9192",
"clpid": "Nandra-K"
},
{
"family_name": "Laird",
"given_name": "E. S.",
"clpid": "Laird-E-S"
},
{
"family_name": "Gwyn",
"given_name": "S.",
"clpid": "Gwyn-S"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Sarajedini",
"given_name": "V. L.",
"clpid": "Sarajedini-V-L"
},
{
"family_name": "Barmby",
"given_name": "P.",
"orcid": "0000-0003-2767-0090",
"clpid": "Barmby-P"
},
{
"family_name": "Faber",
"given_name": "S. M.",
"orcid": "0000-0003-4996-214X",
"clpid": "Faber-S-M"
},
{
"family_name": "Coil",
"given_name": "A. L.",
"clpid": "Coil-A-L"
},
{
"family_name": "Cooper",
"given_name": "M. C.",
"orcid": "0000-0003-1371-6019",
"clpid": "Cooper-M-C"
},
{
"family_name": "Davis",
"given_name": "M.",
"clpid": "Davis-M-E-Astro"
},
{
"family_name": "Newman",
"given_name": "J. A.",
"orcid": "0000-0001-8684-2222",
"clpid": "Newman-J-A"
}
],
"abstract": "In this paper, we discuss the optical and X-ray spectral properties of the sources detected in a single 200-ks Chandra pointing in the Groth-Westphal Strip region. A wealth of optical photometric and spectroscopic data are available in this field providing optical identifications and redshift determinations for the X-ray population. The optical photometry and spectroscopy used here are primarily from the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey with additional redshifts obtained from the literature. These are complemented with the deeper (r \u2248 26 mag) multiwaveband data (ugriz) from the Canada\u2013France\u2013Hawaii Telescope Legacy Survey to estimate photometric redshifts and to optically identify sources fainter than the DEEP2 magnitude limit (R_(AB)\u2248 24.5 mag). We focus our study on the 2\u201310 keV selected sample comprising 97 sources to the limit \u2248 8 \u00d7 10^(\u22121)6 erg s^(\u22121) cm^(\u22122), this being the most complete in terms of optical identification rate (86 per cent) and redshift determination fraction (63 per cent; both spectroscopic and photometric). We first construct the redshift distribution of the sample which shows a peak at z\u2248 1. This is in broad agreement with models where less luminous active galactic nuclei (AGNs) evolve out to z\u2248 1 with powerful quasi-stellar objects (QSOs) peaking at higher redshift, z\u2248 2. Evolution similar to that of broad-line QSOs applied to the entire AGN population (both types I and II) does not fit the data. We also explore the observedNH distribution of the sample and estimate a fraction of obscured AGN (N_H > 10^(22) cm^(\u22122)) of 48 \u00b1 9 per cent. This is found to be consistent with both a luminosity-dependent intrinsic N_H distribution, where less luminous systems comprise a higher fraction of type II AGNs and models with a fixed ratio 2:1 between types I and II AGNs. We further compare our results with those obtained in deeper and shallower surveys. We argue that a luminosity-dependent parametrization of the intrinsic NH distribution is required to account for the fraction of obscured AGN observed in different samples over a wide range of fluxes.",
"doi": "10.1111/j.1365-2966.2006.10634.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2006-09-01",
"series_number": "1",
"volume": "371",
"issue": "1",
"pages": "221-234"
},
{
"id": "authors:wwyy4-afx03",
"collection": "authors",
"collection_id": "wwyy4-afx03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110225-160800612",
"type": "article",
"title": "H\u03b1 Observations of a Large Sample of Galaxies at z ~ 2: Implications for Star Formation in High-Redshift Galaxies",
"author": [
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
}
],
"abstract": "Using H\u03b1 spectra of 114 rest-frame UV-selected galaxies at z ~ 2, we compare inferred star formation rates (SFRs) with those determined from the UV continuum luminosity. After correcting for extinction using standard techniques based on the UV continuum slope, we find excellent agreement between the indicators, with = 31 M_\u2609 yr^(-1) and = 29 M_\u2609 yr^(-1). The agreement between the indicators suggests that the UV luminosity is attenuated by a typical factor of ~4.5 (ranging from no attenuation to a factor of ~100 for the most obscured object in the sample), in good agreement with estimates of obscuration from X-ray, radio, and mid-IR data. The H\u03b1 luminosity is attenuated by a factor of ~1.7 on average, and the maximum H\u03b1 attenuation is a factor of ~5. In agreement with X-ray and mid-IR studies, we find that the SFR increases with increasing stellar mass and at brighter K magnitudes to ~ 60 M_\u2609 yr^(-1) for galaxies with K_s < 20; the correlation between K magnitude and SFR is much stronger than the correlation between stellar mass and SFR. All galaxies in the sample have SFRs per unit area \u03a3_(SFR) in the range observed in local starbursts. We compare the instantaneous SFRs and the past average SFRs as inferred from the ages and stellar masses, finding that for most of the sample, the current SFR is an adequate representation of the past average. There is some evidence that the most massive galaxies (M_* > 10^(11) M_\u2609) have had higher SFRs in the past.",
"doi": "10.1086/505341",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2006-08-10",
"series_number": "1",
"volume": "647",
"issue": "1",
"pages": "128-139"
},
{
"id": "authors:547h9-1ec02",
"collection": "authors",
"collection_id": "547h9-1ec02",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110228-084159205",
"type": "article",
"title": "The Stellar, Gas, and Dynamical Masses of Star-forming Galaxies at z ~ 2",
"author": [
{
"family_name": "Erb",
"given_name": "Dawn K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Reddy",
"given_name": "Naveen A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
},
{
"family_name": "Adelberger",
"given_name": "Kurt. L.",
"clpid": "Adelberger-K-L"
}
],
"abstract": "We present analysis of the near-infrared spectra of 114 rest-frame UV-selected star-forming galaxies at z ~ 2. By combining the H\u03b1 spectra with photometric measurements from observed 0.3-8 \u03bcm, we assess the relationships among kinematics, dynamical masses, inferred gas fractions, and stellar masses and ages. The H\u03b1 line widths give a mean dynamical mass M_(dyn) = (6.9 \u00b1 0.6) \u00d7 10^(10) M_\u2299 within a typical radius of ~6 kpc, after excluding AGNs. The average dynamical mass is ~2 times larger than the average stellar mass, and the two agree to within a factor of several for most objects. However, ~15% of the sample has M_(dyn)\u226b M. These objects are best fit by young stellar populations and tend to have high H\u03b1 equivalent widths, W_(H\u03b1) \u2273 200 \u00c5, suggesting that they are young starbursts with large gas masses. Rest-frame optical luminosity and velocity dispersion are correlated with 4 \u03c3 significance. Using the local empirical correlation between star formation rate per unit area and gas surface density, we estimate the mass of the gas associated with star formation and find a mean gas fraction of ~50% and a strong decrease in gas fraction with increasing stellar mass. The masses of gas and stars combined are considerably better correlated with the dynamical masses than are the stellar masses alone, and agree to within a factor of 3 for 85% of the sample. The combination of kinematic measurements, estimates of gas masses, and stellar population properties suggest that the factor of ~500 range in stellar mass across the sample cannot be fully explained by intrinsic differences in the total masses of the galaxies, which vary by a factor of ~40; the remaining variation is due to the evolution of the stellar population and the conversion of gas into stars.",
"doi": "10.1086/504891",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2006-07-20",
"series_number": "1",
"volume": "646",
"issue": "1",
"pages": "107-132"
},
{
"id": "authors:hqsd6-5ma33",
"collection": "authors",
"collection_id": "hqsd6-5ma33",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110721-114249847",
"type": "article",
"title": "SINFONI Integral Field Spectroscopy of z ~ 2 UV-selected Galaxies: Rotation Curves and Dynamical Evolution",
"author": [
{
"family_name": "F\u00f6rster Schreiber",
"given_name": "N. M.",
"clpid": "F\u00f6rster-Schreiber-N-M"
},
{
"family_name": "Genzel",
"given_name": "R.",
"orcid": "0000-0002-2767-9653",
"clpid": "Genzel-Reinhard"
},
{
"family_name": "Lehnert",
"given_name": "M. D.",
"orcid": "0000-0003-1939-5885",
"clpid": "Lehnert-Matthew-D"
},
{
"family_name": "Bouch\u00e9",
"given_name": "N.",
"clpid": "Bouch\u00e9-N"
},
{
"family_name": "Verma",
"given_name": "A.",
"clpid": "Verma-A"
},
{
"family_name": "Erb",
"given_name": "D. K.",
"orcid": "0000-0001-9714-2758",
"clpid": "Erb-D-K"
},
{
"family_name": "Shapley",
"given_name": "A. E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Davies",
"given_name": "R.",
"clpid": "Davies-R"
},
{
"family_name": "Lutz",
"given_name": "D.",
"orcid": "0000-0003-0291-9582",
"clpid": "Lutz-Dieter"
},
{
"family_name": "Nesvadba",
"given_name": "N.",
"clpid": "Nesvadba-N-P-H"
},
{
"family_name": "Tacconi",
"given_name": "L. J.",
"orcid": "0000-0002-1485-9401",
"clpid": "Tacconi-Linda-J"
},
{
"family_name": "Eisenhauer",
"given_name": "F.",
"clpid": "Eisenhauer-F"
},
{
"family_name": "Abuter",
"given_name": "R.",
"clpid": "Abuter-R"
},
{
"family_name": "Gilbert",
"given_name": "A.",
"clpid": "Gilbert-A-C"
},
{
"family_name": "Gillessen",
"given_name": "S.",
"clpid": "Gillessen-S"
},
{
"family_name": "Sternberg",
"given_name": "A.",
"clpid": "Sternberg-A"
}
],
"abstract": "We present ~0\".5 resolution near-infrared integral field spectroscopy of the H\u03b1 line emission of 14 z ~ 2 UV-selected BM/BX galaxies, obtained with SINFONI at the ESO Very Large Telescope. The average H\u03b1 half-light radius is r_(1/2)\u2248 4 h^(-1)_(70) kpc, and line emission is detected over \u227320 h^(-1)_(70)kpc in several sources. In nine galaxies, we detect spatially resolved velocity gradients, from 40 to 410 km s^(-1) over ~10 h^(-1)_(70) kpc. The kinematics of the larger systems are generally consistent with orbital motions. Four galaxies are well described by rotating clumpy disks, and we extracted rotation curves out to radii \u227310 h^(-1)_(70) kpc. One or two galaxies exhibit signatures more consistent with mergers. Analyzing all 14 galaxies in the framework of rotating disks, we infer mean inclination- and beam-corrected maximum circular velocities of v_c ~ 180 \u00b1 90 km s^(-1) and dynamical masses from ~0.5 to 25 \u00d7 10^(10) h^(-1)_(70) M_\u2609 within r_(1/2). The specific angular momenta of our BM/BX galaxies are similar to those of local late-type galaxies. Moreover, the specific angular momenta of their baryons are comparable to those of their dark matter halos. Extrapolating from the average vc at 10 himg1.gif kpc, the virial mass of the typical halo of a galaxy in our sample is 10^(11.7\u00b10.5) h^(-1)_(70) M_\u2609. Kinematic modeling of the three best cases implies a ratio of v_c to local velocity dispersion v_(c)/\u03c3 ~ 2-4 and, accordingly, a large geometric thickness. We argue that this suggests a mass accretion (alternatively, gas exhaustion) timescale of ~500 Myr. We also argue that if our BM/BX galaxies were initially gas-rich, their clumpy disks would subsequently lose their angular momentum and form compact bulges on a timescale of ~1 Gyr.",
"doi": "10.1086/504403",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2006-07-10",
"series_number": "2",
"volume": "645",
"issue": "2",
"pages": "1062-1075"
},
{
"id": "authors:thfw6-ss396",
"collection": "authors",
"collection_id": "thfw6-ss396",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110217-090330627",
"type": "article",
"title": "Spectroscopy of GRB 050505 at z = 4.275: A log N(H I) = 22.1 DLA host galaxy and the nature of the progenitor",
"author": [
{
"family_name": "Berger",
"given_name": "E.",
"orcid": "0000-0002-9392-9681",
"clpid": "Berger-Edo"
},
{
"family_name": "Penprase",
"given_name": "B. E.",
"clpid": "Penprase-B-E"
},
{
"family_name": "Cenko",
"given_name": "S. B.",
"orcid": "0000-0003-1673-970X",
"clpid": "Cenko-S-B"
},
{
"family_name": "Kulkarni",
"given_name": "S. R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Fox",
"given_name": "D. B.",
"orcid": "0000-0002-3714-672X",
"clpid": "Fox-D-B"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Reddy",
"given_name": "N. A.",
"orcid": "0000-0001-9687-4973",
"clpid": "Reddy-N-A"
}
],
"abstract": "We present optical spectroscopy of the afterglow of GRB 050505 obtained with the Keck I 10 m telescope. The spectrum exhibits three absorption systems with the highest, at z = 4.2748, arising in the host galaxy. The host absorption is marked by a DLA with log N(H i) = 22.05 \u00b1 0.10, higher than that of any QSO-DLA detected to date but similar to several other recent measurements from GRB spectra. We further deduce a metallicity of Z \u2248 0.06 Z_\u2299, with a depletion pattern that is similar to that of the Galactic warm halo or warm disk. More importantly, we detect strong absorption from Si II^* indicating a dense environment, n_H \u2273 10^2 cm^(-3), in the vicinity of the burst, with a size of ~4 pc. The C IV absorption system spans a velocity range of about 10^3 km s^(-1), most likely arising in the progenitor stellar wind. In this context the lack of corresponding Si IV absorption indicates that the progenitor had a mass \u227e 25 M_\u2299 and a metallicity \u227e 0.1 Z_\u2299, and therefore required a binary companion to eject its hydrogen envelope prior to the GRB explosion. Finally, by extending the GRB-DLA sample to z \u2248 4.3 we show that these objects appear to follow a similar metallicity-redshift relation as in QSO-DLAs, but with systematically higher metallicities. It remains to be seen whether this trend is simply due to the higher neutral hydrogen columns in GRB-DLAs and/or sight lines which probe star-forming regions, or if it is a manifestation of different star formation properties in GRB-DLAs.",
"doi": "10.1086/501162",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2006-05-10",
"series_number": "2",
"volume": "642",
"issue": "2",
"pages": "979-988"
},
{
"id": "authors:anwxj-ybx45",
"collection": "authors",
"collection_id": "anwxj-ybx45",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110228-090445852",
"type": "article",
"title": "On the reliability of C IV \u03bb 1549 as an abundance indicator for high-redshift star-forming galaxies",
"author": [
{
"family_name": "Crowther",
"given_name": "Paul A.",
"clpid": "Crowther-P-A"
},
{
"family_name": "Prinja",
"given_name": "Raman K.",
"clpid": "Prinja-R-K"
},
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We reconsider the use of the equivalent width of C IV \u03bb 1549, EW(C IV), as an indicator of the oxygen abundance in star-forming galaxies, as proposed by Heckman et al. for nearby starbursts. We refine the local calibration of EW(C IV) versus log (O/H) by using a restricted wavelength window which minimizes blending with interstellar absorption lines. When applied to the stellar component only of the complex C IV \u03bb 1549 features in two high-redshift galaxies with good quality spectra, MS 1512-cB58 (z = 2.7268) and Q1307-BM1163 (z = 1.4105), the local calibration gives values of the oxygen abundance which are in good agreement with other metallicity determinations based on nebular emission and interstellar absorption lines. Our main conclusion is that for this method to give reliable results at high redshifts, it should only be used on data of sufficiently high spectral resolution (R \u2273 1000) for stellar and interstellar C IV components to be clearly separated. Oxygen abundances will be systematically overestimated if the local calibration is applied to spectra of high-redshift galaxies obtained with the low resolving powers (R \u2243 200 - 300) of many current wide-field surveys. It will also be necessary to understand better the causes of the scatter in the local relation, before we can be confident of inferences from it at high z.",
"doi": "10.1111/j.1365-2966.2006.10164.x",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2006-05",
"series_number": "2",
"volume": "368",
"issue": "2",
"pages": "895-902"
},
{
"id": "authors:c6c0m-qd540",
"collection": "authors",
"collection_id": "c6c0m-qd540",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170408-141820229",
"type": "article",
"title": "A Possible Correlation between the Luminosities and Lifetimes of Active Galactic Nuclei",
"author": [
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "We use the clustering of galaxies around distant AGNs to show with ~90% confidence that fainter AGNs are longer lived. Our argument is simple: since the measured galaxy-AGN cross-correlation length r_0 ~ 5 h^(-1) Mpc does not vary significantly over a 10 mag range in AGN optical luminosity, faint and bright AGNs must reside in dark matter halos with similar masses. The halos that host bright and faint AGNs must therefore have similar abundances, and bright AGNs are rare partly because their lifetimes are short.",
"doi": "10.1086/431789",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2005-09-01",
"series_number": "1",
"volume": "630",
"issue": "1",
"pages": "50-58"
},
{
"id": "authors:18ry8-04f13",
"collection": "authors",
"collection_id": "18ry8-04f13",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170408-154715902",
"type": "article",
"title": "The Faint End of the QSO Luminosity Function at z = 3",
"author": [
{
"family_name": "Hunt",
"given_name": "Matthew P.",
"clpid": "Hunt-M-P"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
}
],
"abstract": "We present the first measurement of the faint end of the QSO luminosity function at z = 3. The QSOs, which range from M_(1450) = -21 to M_(1450) = -27, were discovered in 17 fields totaling 0.43 deg^2 using multicolor selection criteria (the Lyman break technique) and spectroscopic follow-up. We find that the faint-end slope of the luminosity function is \u03b2_l = 1.24 \u00b1 0.07 (\u03a6 \u221d L^(-\u03b2_t)), flatter than the value of \u03b2_l = 1.64 \u00b1 0.18 measured at lower redshift. The integrated rest 1450 \u00c5 UV luminosity of z = 3 QSOs is only 50% of most previous estimates and only sime8% of that produced by Lyman break galaxies at the same redshifts. Assuming that ionizing photons from faint QSOs are as successful in escaping their host galaxies as bright QSOs, we estimate the total contribution of QSOs to the ionizing flux J912 at z ~ 3, J912 \u2243 2.4 \u00d7 10^(-22) ergs s^(-1) cm^(-2) Hz^(-1). This estimate, which we regard as an upper limit, remains consistent with rough estimates of J_(912) based on the Ly\u03b1 forest \"proximity effect.\"",
"doi": "10.1086/381727",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2004-04-20",
"series_number": "2",
"volume": "605",
"issue": "2",
"pages": "625-630"
},
{
"id": "authors:ekw54-ftj07",
"collection": "authors",
"collection_id": "ekw54-ftj07",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191008-111636046",
"type": "article",
"title": "MS 1512\u2013cB58: A case study of star formation, metal enrichment and superwinds in Lyman break galaxies",
"author": [
{
"family_name": "Pettini",
"given_name": "Max",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Rix",
"given_name": "Samantha A.",
"clpid": "Rix-Samantha-A"
},
{
"family_name": "Steidel",
"given_name": "Chuck C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Hunt",
"given_name": "Matthew P.",
"clpid": "Hunt-M-P"
},
{
"family_name": "Shapley",
"given_name": "Alice E.",
"orcid": "0000-0003-3509-4855",
"clpid": "Shapley-A-E"
},
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
}
],
"abstract": "Recent advances in instrumentation and observing techniques have made it possible to begin to study in detail the stellar populations and the interstellar media of galaxies at redshift z = 3, when the universe was still in its 'teen years'. I illustrate recent progress in this field with the latest observations of the gravitationally lensed galaxy MS 1512- cB58.",
"doi": "10.1023/a:1019500911063",
"issn": "0004-640X",
"publisher": "Springer",
"publication": "Astrophysics and Space Science",
"publication_date": "2002-07",
"series_number": "1/2",
"volume": "281",
"issue": "1/2",
"pages": "461-466"
},
{
"id": "authors:qp14j-9qs15",
"collection": "authors",
"collection_id": "qp14j-9qs15",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170228-080833641",
"type": "article",
"title": "Caltech Faint Galaxy Redshift Survey. IX. Source Detection and Photometry in the Hubble Deep Field Region",
"author": [
{
"family_name": "Hogg",
"given_name": "David W.",
"orcid": "0000-0003-2866-9403",
"clpid": "Hogg-D-W"
},
{
"family_name": "Pahre",
"given_name": "Michael A.",
"clpid": "Pahre-M-A"
},
{
"family_name": "Adelberger",
"given_name": "Kurt L.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Blandford",
"given_name": "Roger",
"orcid": "0000-0002-1854-5506",
"clpid": "Blandford-R-D"
},
{
"family_name": "Cohen",
"given_name": "Judith G.",
"orcid": "0000-0002-8039-4673",
"clpid": "Cohen-J-G"
},
{
"family_name": "Gautier",
"given_name": "T. N.",
"clpid": "Gautier-T-N-III"
},
{
"family_name": "Jarrett",
"given_name": "Thomas",
"orcid": "0000-0002-4939-734X",
"clpid": "Jarrett-T-H"
},
{
"family_name": "Neugebauer",
"given_name": "Gerry",
"clpid": "Neugebauer-G"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "Detection and photometry of sources in the U_n, G, \u211b, and K_s bands in a 9 \u00d7 9 arcmin^2 region of the sky, centered on the Hubble Deep Field, are described. The data permit construction of complete photometric catalogs to roughly U_n = 25, G = 26, \u211b = 25.5, K_s = 20 mag and significant photometric measurements somewhat fainter. The galaxy number density is 1.3 \u00d7 10^5 deg^(-2) to \u211b = 25.0 mag. Galaxy number counts have slopes d log N/dm = 0.42, 0.33, 0.27, and 0.31 in the U_n, G, \u211b, and K_s bands, consistent with previous studies and the trend that fainter galaxies are, on average, bluer. Galaxy catalogs selected in the \u211b and K_s bands are presented, containing 3607 and 488 sources in field areas of 74.8 and 59.4 arcmin^2, to \u211b = 25.5 and K_s = 20 mag.",
"doi": "10.1086/313318",
"issn": "0067-0049",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Supplement Series",
"publication_date": "2000-03",
"series_number": "1",
"volume": "127",
"issue": "1",
"pages": "1-9"
},
{
"id": "authors:q63vs-ysk36",
"collection": "authors",
"collection_id": "q63vs-ysk36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141125-150513174",
"type": "article",
"title": "Observing the epoch of galaxy formation",
"author": [
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "Significant observational progress in addressing the question of the origin and early evolution of galaxies has been made in the past few years, allowing for direct comparison of the epoch when most of the stars in the universe were forming to prevailing theoretical models. There is currently broad consistency between theoretical expectations and the observations, but rapid improvement in the data will provide much more critical tests of theory in the coming years.",
"doi": "10.1073/pnas.96.8.4232",
"pmcid": "PMC33559",
"issn": "0027-8424",
"publisher": "National Academy of Sciences",
"publication": "Proceedings of the National Academy of Sciences of the United States of America",
"publication_date": "1999-04-13",
"series_number": "8",
"volume": "96",
"issue": "8",
"pages": "4232-4235"
},
{
"id": "authors:1rgnv-jdc66",
"collection": "authors",
"collection_id": "1rgnv-jdc66",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200929-143507369",
"type": "article",
"title": "Galaxy clustering at z \u223c 3",
"author": [
{
"family_name": "Steidel",
"given_name": "C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Adelberger",
"given_name": "K.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Giavalisco",
"given_name": "M.",
"orcid": "0000-0002-7831-8751",
"clpid": "Giavalisco-M"
},
{
"family_name": "Dickinson",
"given_name": "M.",
"clpid": "Dickinson-M"
},
{
"family_name": "Pettini",
"given_name": "M.",
"orcid": "0000-0002-5139-4359",
"clpid": "Pettini-M"
},
{
"family_name": "Kellogg",
"given_name": "M.",
"clpid": "Kellogg-M"
}
],
"abstract": "Galaxies at very high redshift (z \u223c 3 or greater) are now accessible to wholesale observation, making possible for the first time a robust statistical assessment of their spatial distribution at look\u2013back times approaching ca. 90% of the age of the universe. This paper summarizes recent progress in understanding the nature of these early galaxies, concentrating in particular on the clustering properties. Direct comparison of the data to predictions and physical insights provided by galaxy and structure formation models is particularly straightforward at these early epochs, and results in critical tests of the 'biased' hierarchical galaxy formation paradigm.",
"doi": "10.1098/rsta.1999.0320",
"issn": "1364-503X",
"publisher": "Royal Society of London",
"publication": "Philosophical Transactions A: Mathematical, Physical and Engineering Sciences",
"publication_date": "1999-01-15",
"series_number": "1750",
"volume": "357",
"issue": "1750",
"pages": "153-166"
},
{
"id": "authors:wnzmz-sbr18",
"collection": "authors",
"collection_id": "wnzmz-sbr18",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141126-095046793",
"type": "article",
"title": "Galaxies and large scale structure at high redshifts",
"author": [
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "It is now straightforward to assemble large samples of very high redshift (z \u223c 3) field galaxies selected by their pronounced spectral discontinuity at the rest frame Lyman limit of hydrogen (at 912 \u00c5). This makes possible both statistical analyses of the properties of the galaxies and the first direct glimpse of the progression of the growth of their large-scale distribution at such an early epoch. Here I present a summary of the progress made in these areas to date and some preliminary results of and future plans for a targeted redshift survey at z = 2.7\u20133.4. Also discussed is how the same discovery method may be used to obtain a \"census\" of star formation in the high redshift Universe, and the current implications for the history of galaxy formation as a function of cosmic epoch.",
"doi": "10.1073/pnas.95.1.22",
"pmcid": "PMC34185",
"issn": "0027-8424",
"publisher": "National Academy of Sciences",
"publication": "Proceedings of the National Academy of Sciences of the United States of America",
"publication_date": "1998-01-06",
"series_number": "1",
"volume": "95",
"issue": "1",
"pages": "22-28"
},
{
"id": "authors:39zgd-xp565",
"collection": "authors",
"collection_id": "39zgd-xp565",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130419-091322811",
"type": "article",
"title": "Spectral constraints on the redshift of the optical counterpart to the \u03b3-ray burst of 8 May 1997",
"author": [
{
"family_name": "Metzger",
"given_name": "M. R.",
"clpid": "Metzger-M-R"
},
{
"family_name": "Djorgovski",
"given_name": "S. G.",
"orcid": "0000-0002-0603-3087",
"clpid": "Djorgovski-S-G"
},
{
"family_name": "Kulkarni",
"given_name": "S. R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Steidel",
"given_name": "C. C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Adelberger",
"given_name": "K. L.",
"clpid": "Adelberger-K-L"
},
{
"family_name": "Frail",
"given_name": "D. A.",
"clpid": "Frail-D-A"
},
{
"family_name": "Costa",
"given_name": "E.",
"clpid": "Costa-E"
},
{
"family_name": "Frontera",
"given_name": "F.",
"clpid": "Frontera-F"
}
],
"abstract": "Brief, intense bursts of y-rays occur approximately daily from random directions in space, but their origin has remained unknown since their initial detection almost 25 years ago. Arguments based on their observed isotropy and apparent brightness distribution are not sufficient to constrain the location of the bursts to a local or cosmological origin. The recent detection of a counterpart to a y-ray burst at other wavelengths has therefore\nraised the hope that the sources of these energetic events might soon be revealed. Here we report spectroscopic observations of the possible optical counterpart to the y-ray burst GRB970508. The spectrum is mostly featureless, except for a few prominent absorption lines which we attribute to the presence of an absorption system along the line of sight at redshift z = 0.835. Coupled with the absence of Lyman-\u03b1 forest features in the spectra, our\nresults imply that the optical transient lies at 0.835 \u227e z \u227e 2.3. If the optical transient is indeed the counterpart of GRB970508, our results provide the first direct limits on the distance to a y-ray burst, confirming that at least some of these events lie at cosmological distances, and are thus highly energetic.",
"issn": "0028-0836",
"publisher": "Nature Publishing Group",
"publication": "Nature",
"publication_date": "1997-06-26",
"series_number": "6636",
"volume": "387",
"issue": "6636",
"pages": "878-880"
},
{
"id": "authors:dxw0d-m3y49",
"collection": "authors",
"collection_id": "dxw0d-m3y49",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141202-134228071",
"type": "article",
"title": "The epoch of galaxy formation",
"author": [
{
"family_name": "Spergel",
"given_name": "David N.",
"orcid": "0000-0002-5151-0006",
"clpid": "Spergel-D-N"
},
{
"family_name": "Lilly",
"given_name": "Simon J.",
"orcid": "0000-0002-6423-3597",
"clpid": "Lilly-S-J"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
}
],
"abstract": "Recent advances in technology have enabled astronomers to observe fainter, and more distant, galaxies and to study the processes of galaxy formation and evolution. Recent observations suggest that the bulk of the stars in the universe formed between z = 3 (\u223c1 \u00d7 10^9 years after the big bang) and the present. The star formation rate appears to have peaked at z \u223c 1\u20132 (\u223c 2\u20134 \u00d7 10^9 years after the big bang). While galactic disks appear to form primarily around z = 1, the central regions of spiral galaxies and most elliptical galaxies appear to have been assembled at higher redshift.",
"doi": "10.1073/pnas.94.7.2783",
"pmcid": "PMC34147",
"issn": "0027-8424",
"publisher": "National Academy of Sciences",
"publication": "Proceedings of the National Academy of Sciences of the United States of America",
"publication_date": "1997-04-01",
"series_number": "7",
"volume": "94",
"issue": "7",
"pages": "2783-2784"
},
{
"id": "authors:c9b91-dsk42",
"collection": "authors",
"collection_id": "c9b91-dsk42",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170409-071151363",
"type": "article",
"title": "High-redshift galaxies in the Hubble Deep Field: colour selection and star formation history to z ~ 4",
"author": [
{
"family_name": "Madau",
"given_name": "Piero",
"clpid": "Madau-P"
},
{
"family_name": "Ferguson",
"given_name": "Henry C.",
"orcid": "0000-0001-7113-2738",
"clpid": "Ferguson-H-C"
},
{
"family_name": "Dickinson",
"given_name": "Mark E.",
"orcid": "0000-0001-5414-5131",
"clpid": "Dickinson-Mark-E"
},
{
"family_name": "Giavalisco",
"given_name": "Mauro",
"orcid": "0000-0002-7831-8751",
"clpid": "Giavalisco-M"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Fruchter",
"given_name": "Andrew",
"clpid": "Fruchter-A-S"
}
],
"abstract": "The Lyman decrement associated with the cumulative effect of H I in QSO absorption systems along the line of sight provides a distinctive feature for identifying galaxies at z \u2273 2.5. Colour criteria, which are sensitive to the presence of a Lyman continuum break superposed on an otherwise flat UV spectrum, have been shown, through Keck spectroscopy, to successfully identify a substantial population of star-forming galaxies at 3 \u2272 z \u2272 3.5. Such objects have proven to be surprisingly elusive in field galaxy redshift surveys; quantification of their surface densities and morphologies is crucial for determining how and when galaxies formed. The Hubble Deep Field (HDF) observations offer the opportunity to exploit the ubiquitous effect of intergalactic absorption and obtain useful statistical constraints on the redshift distribution of galaxies to considerably fainter limits than the current spectroscopic limits. We model the H I cosmic opacity as a function of redshift, including scattering in resonant lines of the Lyman series and Lyman continuum absorption, and use stellar population synthesis models with a wide variety of ages, metallicities, dust contents and redshifts to derive colour selection criteria that provide a robust separation between high-redshift and low-redshift galaxies. From the HDF images we construct a sample of star-forming galaxies at 2 \u2272z \u2272 4.5. While none of the \u223c 60 objects in the HDF having known Keck/Low-Resolution Imaging Spectrograph (LRIS) spectroscopic redshifts in the range 0 \u2272 z \u22721.4 is found to contaminate our high-redshift sample, our colour criteria are able to efficiently select the 2.6 \u2272 z \u2272 3.2 galaxies identified by Steidel et al. \n\nThe ultraviolet (and blue) dropout technique opens up the possibility of investigating cosmic star and element formation in the early Universe. We set a lower limit to the ejection rate of heavy elements per unit comoving volume from Type II supernovae at \u3008z\u3009 = 2.75 of \u2248 3.6 \u00d7 10^(\u22124) M_\u2299 yr^(\u22121) Mpc^(\u22123) (for q_0 = 0.5 and H_0 = 50 km s^(\u22121) Mpc^(\u22121)), which is 3 times higher than the local value but still 4 times lower than the rate observed at z \u2248 1. At \u3008z\u3009 = 4, our lower limit to the cosmic metal ejection rate is \u2248 3 times lower than the \u3008z\u3009 = 2.75 value. We discuss the implications of these results on models of galaxy formation, and on the chemical enrichment and ionization history of the intergalactic medium.",
"doi": "10.1093/mnras/283.4.1388",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "1996-12-31",
"series_number": "4",
"volume": "283",
"issue": "4",
"pages": "1388-1404"
},
{
"id": "authors:20zen-n9n07",
"collection": "authors",
"collection_id": "20zen-n9n07",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190507-145525566",
"type": "article",
"title": "Spectrum of a QSO with redshift 3.8",
"author": [
{
"family_name": "Sargent",
"given_name": "Wallace L. W.",
"clpid": "Sargent-W-L-W"
},
{
"family_name": "Filippenko",
"given_name": "Alexei V.",
"orcid": "0000-0003-3460-0103",
"clpid": "Filippenko-A-V"
},
{
"family_name": "Steidel",
"given_name": "Charles C.",
"orcid": "0000-0002-4834-7260",
"clpid": "Steidel-C-C"
},
{
"family_name": "Hazard",
"given_name": "Cyril",
"clpid": "Hazard-C"
},
{
"family_name": "McMahon",
"given_name": "Richard G.",
"clpid": "McMahon-R-G"
}
],
"abstract": "Hazard et al. have described the circumstances leading to the identification of a quasi-stellar object (QSO) (1208 + 1011) with z = 3.82 \u00b1 0.04. Here we present a moderate-resolution optical spectrum of this object. Its precise redshift, z = 3.803 \u00b1 0.005, is the highest ever recorded.",
"doi": "10.1038/322040a0",
"issn": "0028-0836",
"publisher": "Nature Publishing Group",
"publication": "Nature",
"publication_date": "1986-07-03",
"series_number": "6074",
"volume": "322",
"issue": "6074",
"pages": "40-42"
}
]