[ { "id": "authors:ndmn5-08h55", "collection": "authors", "collection_id": "ndmn5-08h55", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201016-131847697", "type": "article", "title": "Extended Radio AGN at z \u223c 1 in the ORELSE Survey: The Confining Effect of Dense Environments", "author": [ { "family_name": "Shen", "given_name": "Lu", "orcid": "0000-0001-9495-7759", "clpid": "Shen-Lu" }, { "family_name": "Liu", "given_name": "Guilin", "orcid": "0000-0003-2390-7927", "clpid": "Liu-Guilin" }, { "family_name": "Zhang", "given_name": "Meng-Fei", "orcid": "0000-0001-8261-3254", "clpid": "Zhang-Meng-Fei" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "Lori M.", "orcid": "0000-0003-4249-5315", "clpid": "Lubin-L-M" }, { "family_name": "Pelliccia", "given_name": "Debora", "orcid": "0000-0002-3007-0013", "clpid": "Pelliccia-D" }, { "family_name": "Moravec", "given_name": "Emily", "orcid": "0000-0001-9793-5416", "clpid": "Moravec-Emily" }, { "family_name": "Golden-Marx", "given_name": "Emmet", "orcid": "0000-0001-5160-6713", "clpid": "Golden-Marx-E" }, { "family_name": "Zhou", "given_name": "Hongyan", "orcid": "0000-0003-1956-9021", "clpid": "Zhou-Hongyan" }, { "family_name": "Fang", "given_name": "Wenjuan", "clpid": "Fang-Wenjuan" }, { "family_name": "Tomczak", "given_name": "Adam", "orcid": "0000-0003-2008-1752", "clpid": "Tomczak-A-R" }, { "family_name": "McKean", "given_name": "John", "clpid": "McKean-John" }, { "family_name": "Miller", "given_name": "Neal A.", "orcid": "0000-0003-1076-7558", "clpid": "Miller-N-A" }, { "family_name": "Fassnacht", "given_name": "Christopher D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Wu", "given_name": "Po-Feng", "orcid": "0000-0002-9665-0440", "clpid": "Wu-Po-Feng" }, { "family_name": "Kocevski", "given_name": "Dale", "clpid": "Kocevski-D-D" }, { "family_name": "Gal", "given_name": "Roy", "orcid": "0000-0001-8255-6560", "clpid": "Gal-R-R" }, { "family_name": "Hung", "given_name": "Denise", "orcid": "0000-0001-7523-140X", "clpid": "Hung-Denise" }, { "family_name": "Squires", "given_name": "Gordon", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "Recent hydrodynamic simulations and observations of radio jets have shown that the surrounding environment has a large effect on their resulting morphology. To investigate this, we use a sample of 50 Extended Radio Active Galactic Nuclei (ERAGN) detected in the Observations of Redshift Evolution in Large-Scale Environments survey. These sources are all successfully cross-identified to galaxies within a redshift range of 0.55 \u2264 z \u2264 1.35, either through spectroscopic redshifts or accurate photometric redshifts. We find that ERAGN are more compact in high-density environments than those in low-density environments at a significance level of 4.5\u03c3. Among a series of internal properties under our scrutiny, only the radio power demonstrates a positive correlation with their spatial extent. After removing the possible radio power effect, the difference of size in low- and high-density environments persists. In the global environment analyses, the majority (86%) of high-density ERAGN reside in the cluster/group environment. In addition, ERAGN in the cluster/group central regions are preferentially compact with a small scatter in size, compared to those in the cluster/group intermediate regions and fields. In conclusion, our data appear to support the interpretation that the dense intracluster gas in the central regions of galaxy clusters plays a major role in confining the spatial extent of radio jets.", "doi": "10.3847/1538-4357/abb5a0", "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. 101" }, { "id": "authors:ajer7-zyw02", "collection": "authors", "collection_id": "ajer7-zyw02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200625-112850473", "type": "article", "title": "The properties of radio and mid-infrared detected galaxies and the effect of environment on the co-evolution of AGN and star formation at z \u223c 1", "author": [ { "family_name": "Shen", "given_name": "Lu", "orcid": "0000-0001-9495-7759", "clpid": "Shen-Lu" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "Lori M.", "orcid": "0000-0003-4249-5315", "clpid": "Lubin-L-M" }, { "family_name": "McKean", "given_name": "John", "clpid": "McKean-J" }, { "family_name": "Miller", "given_name": "Neal A.", "orcid": "0000-0003-1076-7558", "clpid": "Miller-N-A" }, { "family_name": "Pelliccia", "given_name": "Debora", "orcid": "0000-0002-3007-0013", "clpid": "Pelliccia-D" }, { "family_name": "Fassnacht", "given_name": "Christopher D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Tomczak", "given_name": "Adam", "orcid": "0000-0003-2008-1752", "clpid": "Tomczak-A-R" }, { "family_name": "Wu", "given_name": "Po-Feng", "orcid": "0000-0002-9665-0440", "clpid": "Wu-Po-Feng" }, { "family_name": "Kocevski", "given_name": "Dale", "clpid": "Kocevski-D-D" }, { "family_name": "Gal", "given_name": "Roy", "orcid": "0000-0001-8255-6560", "clpid": "Gal-R-R" }, { "family_name": "Hung", "given_name": "Denise", "orcid": "0000-0001-7523-140X", "clpid": "Hung-Denise" }, { "family_name": "Squires", "given_name": "Gordon", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "In this study, we investigate 179 radio-infrared (IR) galaxies drawn from a sample of spectroscopically confirmed galaxies, which are detected in radio and mid-IR (MIR) in the redshift range of 0.55 \u2264 z \u2264 1.30 in the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. We constrain the active galactic nuclei (AGN) contribution to the total IR luminosity (f_(AGN)), and estimate the AGN luminosity (L_(AGN)) and the star formation rate (SFR). Based on the f_(AGN) and radio luminosity, radio\u2013IR galaxies are split into galaxies that host either high- or low-f_(AGN) AGN (high-/low-f_(AGN)), and star-forming galaxies (SFGs) with little to no AGN activity. We study the properties of the three radio\u2013IR sub-samples comparing to an underlying parent sample. In the comparison of radio luminosity of three sub-samples, no significant difference was found, which could be due to the combined contribution of radio emission from AGN and star formation. We find a positive relationship between L_(AGN) and specific SFR (sSFR) for both AGN sub-samples, strongly suggesting a co-evolution scenario of AGN and SF in these galaxies. A toy model is designed to demonstrate this co-evolution scenario, where we find that, in almost all cases, a rapid quenching time-scale is required, which we argue is a signature of AGN quenching. The environmental preference for intermediate/infall regions of clusters/groups remains across the co-evolution scenario, which suggests that galaxies might be in an orbital motion around the cluster/group during the scenario.", "doi": "10.1093/mnras/staa1005", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2020-06-01", "series_number": "4", "volume": "494", "issue": "4", "pages": "5374-5395" }, { "id": "authors:sxd91-52f79", "collection": "authors", "collection_id": "sxd91-52f79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200228-100723182", "type": "article", "title": "Establishing a New Technique for Discovering Large-Scale Structure Using the ORELSE Survey", "author": [ { "family_name": "Hung", "given_name": "D.", "orcid": "0000-0001-7523-140X", "clpid": "Hung-Denise" }, { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Tomczak", "given_name": "A. R.", "orcid": "0000-0003-2008-1752", "clpid": "Tomczak-A-R" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Cucciati", "given_name": "O.", "orcid": "0000-0002-9336-7551", "clpid": "Cucciati-O" }, { "family_name": "Pelliccia", "given_name": "D.", "clpid": "Pelliccia-D" }, { "family_name": "Shen", "given_name": "L.", "clpid": "Shen-L" }, { "family_name": "Le F\u00e8vre", "given_name": "O.", "orcid": "0000-0001-5891-2596", "clpid": "Le-F\u00e8vre-O" }, { "family_name": "Wu", "given_name": "P-F.", "clpid": "Wu-P-F" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "Mei", "given_name": "S.", "orcid": "0000-0002-2849-559X", "clpid": "Mei-Simona" }, { "family_name": "Squires", "given_name": "G", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "The Observations of Redshift Evolution in Large-Scale Environments (ORELSE) survey is an ongoing imaging and spectroscopic campaign initially designed to study the effects of environment on galaxy evolution in high-redshift (z \u223c 1) large-scale structures. We use its rich data in combination with a powerful new technique, Voronoi tessellation Monte Carlo (VMC) mapping, to search for serendipitous galaxy overdensities at 0.55 < z < 1.37 within 15 ORELSE fields, a combined spectroscopic footprint of \u223c1.4 deg\u00b2. Through extensive tests with both observational data and our own mock galaxy catalogues, we optimize the method's many free parameters to maximize its efficacy for general overdensity searches. Our overdensity search yielded 402 new overdensity candidates with precisely measured redshifts and an unprecedented sensitivity down to low total overdensity masses (\u2060M_(tot) \u2273 5\u00d710\u00b9\u00b3 M\u2299). Using the mock catalogues, we estimated the purity and completeness of our overdensity catalogue as a function of redshift, total mass, and spectroscopic redshift fraction, finding impressive levels of both 0.92/0.83 and 0.60/0.49 for purity/completeness at z = 0.8 and z = 1.2, respectively, for all overdensity masses at spectroscopic fractions of \u223c20 per\u2009cent. With VMC mapping, we are able to measure precise systemic redshifts, provide an estimate of the total gravitating mass, and maintain high levels of purity and completeness at z \u223c 1 even with only moderate levels of spectroscopy. Other methods (e.g. red-sequence overdensities and hot medium reliant detections) begin to fail at similar redshifts, which attests to VMC mapping's potential to be a powerful tool for current and future wide-field galaxy evolution surveys at z \u223c 1 and beyond.", "doi": "10.1093/mnras/stz3164", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2020-02", "series_number": "4", "volume": "491", "issue": "4", "pages": "5524-5554" }, { "id": "authors:hw0w5-bcj97", "collection": "authors", "collection_id": "hw0w5-bcj97", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190411-155933275", "type": "article", "title": "Possible evidence of the radio AGN quenching of neighbouring galaxies at z \u223c 1", "author": [ { "family_name": "Shen", "given_name": "Lu", "clpid": "Shen-Lu" }, { "family_name": "Tomczak", "given_name": "Adam R.", "orcid": "0000-0003-2008-1752", "clpid": "Tomczak-A-R" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Pelliccia", "given_name": "Debora", "clpid": "Pelliccia-D" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Miller", "given_name": "Neal A.", "clpid": "Miller-N-A" }, { "family_name": "Perrotta", "given_name": "Serena", "clpid": "Perrotta-S" }, { "family_name": "Fassnacht", "given_name": "Christopher D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Becker", "given_name": "Robert H.", "clpid": "Becker-R-H" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Wu", "given_name": "Po-Feng", "clpid": "Wu-Po-Feng" }, { "family_name": "Squires", "given_name": "Gordon", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "Using 57 radio active galactic nuclei (RAGNs) at 0.55 \u2264 z \u2264 1.3 drawn from five fields of the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) survey, we study the effect of injection of energy from outbursts of RAGN on their spectroscopically confirmed neighbouring galaxies (SNGs). We observe an elevated fraction of quenched neighbours (f_q) within 500 kpc projected radius of RAGN in the most dense local environments compared to those of non-RAGN control samples matched to the RAGN population in colour, stellar mass, and local environment at 2\u03c3 significance. Further analyses show that there are offsets at similar significance between f_qs of RAGN-SNGs and the appropriate control samples for galaxies specifically in cluster environments and those hosted by most massive cluster galaxies, which tentatively suggests that some negative feedback from the RAGN is occurring in these dense environments. In addition, we find that the median radio power of RAGN increases with increasing local overdensity, an effect which may lend itself to the quenching of neighbouring galaxies. Furthermore, we find that, in the highest local overdensities, the f_q of the sub-sample of lower stellar mass RAGN-SNGs is larger than that of the higher stellar mass RAGN-SNGs sub-sample, which indicates a more pronounced effect from RAGN on lower stellar mass galaxies. We propose a scenario in which RAGN residing within clusters might heat the intracluster medium (ICM) affecting both in situ star formation and any inflowing gas that remains in their neighbouring galaxies.", "doi": "10.1093/mnras/stz152", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-04", "series_number": "2", "volume": "484", "issue": "2", "pages": "2433-2446" }, { "id": "authors:kx4p9-as835", "collection": "authors", "collection_id": "kx4p9-as835", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190415-140238083", "type": "article", "title": "Searching for environmental effects on galaxy kinematics in groups and clusters at z \u223c 1 from the ORELSE survey", "author": [ { "family_name": "Pelliccia", "given_name": "Debora", "clpid": "Pelliccia-D" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Tomczak", "given_name": "Adam R.", "orcid": "0000-0003-2008-1752", "clpid": "Tomczak-A-R" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Shen", "given_name": "Lu", "clpid": "Shen-Lu" }, { "family_name": "Epinat", "given_name": "Beno\u00eet", "clpid": "Epinat-B" }, { "family_name": "Wu", "given_name": "Po-Feng", "clpid": "Wu-Po-Feng" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Rumbaugh", "given_name": "Nicholas", "clpid": "Rumbaugh-N" }, { "family_name": "Kocevski", "given_name": "Dale D.", "clpid": "Kocevski-D-D" }, { "family_name": "Tresse", "given_name": "Laurence", "clpid": "Tresse-L" }, { "family_name": "Squires", "given_name": "Gordon", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We present an investigation of the dependence of galaxy kinematics on the environment for a sample of 94 star-forming galaxies at z \u223c 0.9 from the ORELSE survey. ORELSE is a large photometric and spectroscopic campaign dedicated to mapping out and characterizing galaxy properties across a full range of environments in 15 fields containing large-scale structures (LSSs) in a redshift range of 0.6 < z < 1.3. We constrained the rotation velocity for our kinematic sample in an ORELSE field, containing the SC1604 supercluster, by fitting high-resolution semi-analytical models to the data. We constructed the stellar-mass/B-band Tully\u2013Fisher relation and found no dependence of the intrinsic scatter on both local and global environment. Moreover, we compared the stellar-to-dynamical mass ratio (M*/M_(dyn)) of SC1604 galaxies to those residing in less dense local environment by leveraging data from the HR-COSMOS sample. We found that, at fixed stellar mass, SC1604 galaxies have \u223c30 per cent smaller dynamical masses on average. By comparing the distributions of the galaxy parameters that define M_(dyn) (i.e., circular velocity and the characteristic radius r_(2.2)) between SC1604 and HR-COSMOS, we found that smaller dynamical masses are mostly caused by smaller r_(2.2) for SC1604 galaxies. We also observed that SC1604 galaxies in general show \u223c20 per cent lower stellar specific angular momentum (j*) with respect to the HR-COSMOS sample. Adopting literature estimates for (1) the excess rate of galaxy\u2013galaxy mergers in intermediate/high-density environments and (2) the average amount of j* loss per merger event, we investigated the possibility that galaxy mergers are mainly responsible for the loss of angular momentum in higher density environments.", "doi": "10.1093/mnras/sty2876", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-01", "series_number": "3", "volume": "482", "issue": "3", "pages": "3514-3549" }, { "id": "authors:dt027-52785", "collection": "authors", "collection_id": "dt027-52785", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171117-124639567", "type": "article", "title": "The properties of radio galaxies and the effect of environment in large-scale structures at z \u223c 1", "author": [ { "family_name": "Shen", "given_name": "Lu", "clpid": "Shen-Lu" }, { "family_name": "Miller", "given_name": "Neal A.", "clpid": "Miller-N-A" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Tomczak", "given_name": "Adam R.", "orcid": "0000-0003-2008-1752", "clpid": "Tomczak-A-R" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Rumbaugh", "given_name": "Nicholas", "clpid": "Rumbaugh-N" }, { "family_name": "Fassnacht", "given_name": "Christopher D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Becker", "given_name": "Robert H.", "clpid": "Becker-R-H" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Wu", "given_name": "Po-Feng", "clpid": "Wu-Po-Feng" }, { "family_name": "Squires", "given_name": "Gordon", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "In this study, we investigate 89 radio galaxies that are spectroscopically confirmed to be members of five large-scale structures (LSSs) in the redshift range of 0.65 \u2264 z \u2264 0.96. Based on a two-stage classification scheme, the radio galaxies are classified into three sub-classes: active galactic nucleus (AGN), Hybrid, and star-forming galaxy (SFG). We study the properties of the three radio sub-classes and their global and local environmental preferences. We find AGN hosts are the most massive population and exhibit quiescence in their star formation activity. The SFG population has a comparable stellar mass to those hosting a radio AGN but are unequivocally powered by star formation. Hybrids, though selected as an intermediate population in our classification scheme, were found in almost all analyses to be a unique type of radio galaxies rather than a mixture of AGN and SFGs. They are dominated by a high-excitation radio galaxy population. We discuss environmental effects and scenarios for each sub-class. AGN tend to be preferentially located in locally dense environments and in the cores of clusters/groups, with these preferences persisting when comparing to galaxies of similar colour and stellar mass, suggesting that their activity may be ignited in the cluster/group virialized core regions. Conversely, SFGs exhibit a strong preference for intermediate-density global environments, suggesting that dusty starbursting activity in LSSs is largely driven by galaxy\u2013galaxy interactions and merging.", "doi": "10.1093/mnras/stx1984", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2017-11-21", "series_number": "1", "volume": "472", "issue": "1", "pages": "998-1022" }, { "id": "authors:t5m91-5tf32", "collection": "authors", "collection_id": "t5m91-5tf32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171117-090119022", "type": "article", "title": "Chronos and KAIROS: MOSFIRE observations of post-starburst galaxies in z \u223c 1 clusters and groups", "author": [ { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Tomczak", "given_name": "A. R.", "orcid": "0000-0003-2008-1752", "clpid": "Tomczak-A-R" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Wu", "given_name": "P-F.", "clpid": "Wu-P-F" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Rumbaugh", "given_name": "N.", "clpid": "Rumbaugh-N" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We present an exploration of \u223c500 spectroscopically confirmed galaxies in and around two large-scale structures (LSSs) at z \u223c 1 drawn from the Observations of Redshift Evolution in Large Scale Environments survey, an ongoing, wide-field photometric and spectroscopic campaign targeting a large ensemble of LSSs at 0.6 < z < 1.3. A sub-sample of these galaxies (\u223c150) was targeted for the initial phase of a near-infrared MOSFIRE spectroscopic campaign investigating the differences in selections of galaxies that had recently ended a burst of star formation and/or had rapidly quenched (i.e. post-starburst/K+A galaxies). Selection with MOSFIRE utilizing the H\u2009\u03b1 and [N\u2009II] emission features resulted in a post-starburst sample more than double that selected by traditional z \u223c 1 (observed-frame optical) methods even after the removal of the relatively large fraction of dusty starburst galaxies selected through traditional methods. While the traditional post-starburst fraction increased with increasing global density, the MOSFIRE-selected post-starburst fraction was found to be constant across field, group, and cluster environments. However, this fraction computed relative to the number of star-forming galaxies was observed to elevate in the cluster environment. Post-starbursts selected with MOSFIRE exhibited moderately strong [O\u2009II] emission originating from activity other than star formation. Such galaxies, termed K+A with ImposteR [O\u2009II]-derived Star formation (KAIROS) galaxies, were found to be younger than and likely undergoing feedback absent or diminished in their optically selected counterparts. A comparison between the environments of the two types of post-starbursts suggested a picture in which the evolution of a post-starburst galaxy is considerably different in cluster environments than in the more rarefied environments of a group or the field.", "doi": "10.1093/mnras/stx1579", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2017-11-21", "series_number": "1", "volume": "472", "issue": "1", "pages": "419-438" }, { "id": "authors:y1yhc-4av16", "collection": "authors", "collection_id": "y1yhc-4av16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170921-112700974", "type": "article", "title": "Suppressed star formation by a merging cluster system", "author": [ { "family_name": "Mansheim", "given_name": "A. S.", "clpid": "Mansheim-A-S" }, { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Tomczak", "given_name": "A. R.", "orcid": "0000-0003-2008-1752", "clpid": "Tomczak-A-R" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Rumbaugh", "given_name": "N.", "clpid": "Rumbaugh-N" }, { "family_name": "Wu", "given_name": "P.-F.", "clpid": "Wu-P-F" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Shen", "given_name": "L.", "clpid": "Shen-L" }, { "family_name": "Dawson", "given_name": "W. A.", "clpid": "Dawson-W-A" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We examine the effects of an impending cluster merger on galaxies in the large-scale structure (LSS) RX J0910 at z =1.105. Using multiwavelength data, including 102 spectral members drawn from the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey and precise photometric redshifts, we calculate star formation rates and map the specific star formation rate density of the LSS galaxies. These analyses along with an investigation of the colour\u2013magnitude properties of LSS galaxies indicate lower levels of star formation activity in the region between the merging clusters relative to the outskirts of the system. We suggest that gravitational tidal forces due to the potential of the merging haloes may be the physical mechanism responsible for the observed suppression of star formation in galaxies caught between the merging clusters.", "doi": "10.1093/mnrasl/slx041", "issn": "1745-3925", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society: Letters", "publication_date": "2017-07", "series_number": "1", "volume": "469", "issue": "1", "pages": "L20-L25" }, { "id": "authors:p1wsc-qcj39", "collection": "authors", "collection_id": "p1wsc-qcj39", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170428-100719188", "type": "article", "title": "X-ray-emitting active galactic nuclei from z = 0.6 to 1.3 in the intermediate- and high-density environments of the ORELSE survey", "author": [ { "family_name": "Rumbaugh", "given_name": "N.", "clpid": "Rumbaugh-N" }, { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Tomczak", "given_name": "A.", "clpid": "Tomczak-A" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Wu", "given_name": "P.-F.", "clpid": "Wu-P-F" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Shen", "given_name": "L.", "clpid": "Shen-L" }, { "family_name": "Mansheim", "given_name": "A.", "clpid": "Mansheim-A" }, { "family_name": "Fassnacht", "given_name": "C. D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We studied active galactic nucleus (AGN) activity in 12 large-scale structures (LSSs) in the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) survey, at 0.65 < z < 1.28, using a combination of Chandra observations, optical and NIR imaging and spectroscopy. We located a total of 61 AGNs that were successfully matched to optical counterparts in the LSSs. We found that AGN populations across our sample had more recently had starburst events compared to the overall galaxy populations. We find no relation between AGN activity and location within the LSSs, suggesting triggering mechanisms that depend on global environment are at most sub-dominant. To focus on differences between our AGNs, we grouped them into four sub-samples based on the spectral properties of their parents LSSs. We found one of the sub-samples, SG0023 & SC1604, stood out from the others. AGNs in this sample were disproportionately luminous. These AGNs had the most recent starburst events, in contrast to their parent populations. Additionally, both the AGNs and the overall galaxy population in SG0023 & SC1604 had the largest fraction of close kinematic pairs, which indicates a higher rate of galaxy mergers and interactions. These results suggest that major mergers are driving AGN activity in SG0023 & SC1604, while other processes are likely triggering less luminous AGNs in the rest of our sample. Additionally, minor mergers are unlikely to play a significant role, since the same conditions that lead to more major mergers should also lead to more minor mergers, which is not observed in SG0023 & SC1604.", "doi": "10.1093/mnras/stw3091", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2017-04", "series_number": "1", "volume": "466", "issue": "1", "pages": "496-519" }, { "id": "authors:rewwx-8r917", "collection": "authors", "collection_id": "rewwx-8r917", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150205-145150186", "type": "article", "title": "On the Intermediate-redshift Central Stellar Mass-Halo Mass Relation, and Implications for the Evolution of the Most Massive Galaxies Since z ~ 1", "author": [ { "family_name": "Shankar", "given_name": "Francesco", "clpid": "Shankar-F" }, { "family_name": "Guo", "given_name": "Hong", "clpid": "Guo-Hong" }, { "family_name": "Bouillot", "given_name": "Vincent", "clpid": "Bouillot-V-R" }, { "family_name": "Rettura", "given_name": "Alessandro", "orcid": "0000-0002-5615-256X", "clpid": "Rettura-A" }, { "family_name": "Meert", "given_name": "Alan", "clpid": "Mert-Alan" }, { "family_name": "Buchan", "given_name": "Stewart", "clpid": "Buchan-Stewart" }, { "family_name": "Kravtsov", "given_name": "Andrey", "clpid": "Kravtsov-A-V" }, { "family_name": "Bernardi", "given_name": "Mariangela", "clpid": "Bernardi-Mariangela" }, { "family_name": "Sheth", "given_name": "Ravi", "clpid": "Sheth-R-K" }, { "family_name": "Vikram", "given_name": "Vinu", "clpid": "Vikram-Vinu" }, { "family_name": "Marchesini", "given_name": "Danilo", "orcid": "0000-0001-9002-3502", "clpid": "Marchesini-D" }, { "family_name": "Behroozi", "given_name": "Peter", "clpid": "Behroozi-P-S" }, { "family_name": "Zheng", "given_name": "Zheng", "clpid": "Zheng-Zheng" }, { "family_name": "Maraston", "given_name": "Claudia", "orcid": "0000-0001-7711-3677", "clpid": "Maraston-C" }, { "family_name": "Ascaso", "given_name": "Bego\u00f1a", "clpid": "Ascaso-B" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Capozzi", "given_name": "Diego", "clpid": "Capozzi-D" }, { "family_name": "Huertas-Company", "given_name": "Marc", "clpid": "Huertas-Company-M" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Conselice", "given_name": "Christopher J.", "orcid": "0000-0003-1949-7638", "clpid": "Conselice-C-J" }, { "family_name": "Carollo", "given_name": "Marcella C.", "orcid": "0000-0003-1624-7609", "clpid": "Carollo-C-Marcella" }, { "family_name": "Cattaneo", "given_name": "Andrea", "clpid": "Cattaneo-Andrea" } ], "abstract": "The stellar mass-halo mass relation is a key constraint in all semi-analytic, numerical, and semi-empirical models of galaxy formation and evolution. However, its exact shape and redshift dependence remain under debate. Several recent works support a relation in the local universe steeper than previously thought. Based on comparisons with a variety of data on massive central galaxies, we show that this steepening holds up to z ~ 1 for stellar masses M_(star)\u22732 \u00d7 10^(11) M_\u2609. Specifically, we find significant evidence for a high-mass end slope of \u03b2 \u2273 0.35-0.70 instead of the usual \u03b2 \u227e 0.20-0.30 reported by a number of previous results. When including the independent constraints from the recent Baryon Oscillation Spectroscopic Survey clustering measurements, the data, independent of any systematic errors in stellar masses, tend to favor a model with a very small scatter (\u227e 0.15 dex) in stellar mass at fixed halo mass, in the redshift range z < 0.8 and for M_(star) > 3 \u00d7 10^(11) M_\u2609, suggesting a close connection between massive galaxies and host halos even at relatively recent epochs. We discuss the implications of our results with respect to the evolution of the most massive galaxies since z ~ 1.", "doi": "10.1088/2041-8205/797/2/L27", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2014-12-20", "series_number": "2", "volume": "797", "issue": "2", "pages": "Art. No. L27" }, { "id": "authors:rq83p-5kv87", "collection": "authors", "collection_id": "rq83p-5kv87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150115-115607253", "type": "article", "title": "Hidden starbursts and active galactic nuclei at 0< z <4 from the Herschel-VVDS-CFHTLS-D1 field: Inferences on coevolution and feedback", "author": [ { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Le Floc'h", "given_name": "E.", "clpid": "Le-Floc'h-Emeric" }, { "family_name": "Le F\u00e8vre", "given_name": "O.", "orcid": "0000-0001-5891-2596", "clpid": "Le-F\u00e8vre-O" }, { "family_name": "Ilbert", "given_name": "O.", "orcid": "0000-0002-7303-4397", "clpid": "Ilbert-Olivier" }, { "family_name": "Tresse", "given_name": "L.", "clpid": "Tresse-L" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Zamorani", "given_name": "G.", "clpid": "Zamorani-G" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Ciliegi", "given_name": "P.", "clpid": "Ciliegi-P" }, { "family_name": "Cassata", "given_name": "P.", "clpid": "Cassata-P" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "McGrath", "given_name": "E. J.", "clpid": "McGrath-E-J" }, { "family_name": "Bardelli", "given_name": "S.", "clpid": "Bardelli-S" }, { "family_name": "Zucca", "given_name": "E.", "clpid": "Zucca-E" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We investigate of the properties of \u223c2000 Herschel/SPIRE far-infrared-selected galaxies from 0 < z < 4 in the CFHTLS-D1 field. Using a combination of extensive spectroscopy from the VVDS and ORELSE surveys, deep multiwavelength imaging from CFHT, VLA, Spitzer, XMM-Newton, and Herschel, and well-calibrated spectral energy distribution fitting, Herschel-bright galaxies are compared to optically-selected galaxies at a variety of redshifts. Herschel-selected galaxies are observed to span a range of stellar masses, colors, and absolute magnitudes equivalent to galaxies undetected in SPIRE. Though many Herschel galaxies appear to be in transition, such galaxies are largely consistent with normal star-forming galaxies when rest-frame colors are utilized. The nature of the\nstar-forming \"main sequence\" is studied and we warn against adopting this framework unless the main sequence is determined precisely. Herschel galaxies at different total infrared luminosities (L_TIR) are compared. Bluer optical colors, larger nebular extinctions, and larger contributions from younger stellar populations are observed for galaxies with larger L_TIR, suggesting that low-L_TIR galaxies are undergoing rejuvenated starbursts while galaxies with higher L_TIR are forming a larger percentage of their stellar mass. A variety of methods are used to select powerful active galactic nuclei (AGN). Galaxies hosting all types of AGN are observed to be undergoing\nstarbursts more commonly and vigorously than a matched sample of galaxies without powerful AGN and, additionally, the fraction of galaxies with an AGN increases with increasing star formation rate at all redshifts. At all redshifts (0 < z < 4) the most prodigious star-forming galaxies are found to contain the highest fraction of powerful AGN. For redshift bins that allow a comparison (z > 0.5), the highest LTIR galaxies in a given redshift bin are unobserved by SPIRE at subsequently lower redshifts, a trend linked to downsizing. In conjunction with other results, this evidence is used to argue for prevalent AGN-driven quenching in starburst galaxies across\ncosmic time.", "doi": "10.1051/0004-6361/201323089", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2014-12", "volume": "572", "pages": "Art. No. A90" }, { "id": "authors:54vzz-6y397", "collection": "authors", "collection_id": "54vzz-6y397", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140925-081927253", "type": "article", "title": "Star Formation Quenching in High-redshift Large-scale Structure: Post-starburst Galaxies in the Cl 1604 Supercluster at z\u223c0.9", "author": [ { "family_name": "Wu", "given_name": "Po-Feng", "clpid": "Wu-P-F" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Kocevski", "given_name": "Dale D.", "clpid": "Kocevski-D-D" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Rumbaugh", "given_name": "Nicholas", "clpid": "Rumbaugh-N" }, { "family_name": "Squires", "given_name": "Gordon K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "The Cl 1604 supercluster at z ~ 0.9 is one of the most extensively studied high-redshift large-scale structures, with more than 500 spectroscopically confirmed members. It consists of eight clusters and groups, with members numbering from a dozen to nearly a hundred, providing a broad range of environments for investigating the large-scale environmental effects on galaxy evolution. Here we examine the properties of 48 post-starburst galaxies in Cl 1604, comparing them to other galaxy populations in the same supercluster. Incorporating photometry from ground-based optical and near-infrared imaging, along with Spitzer mid-infrared observations, we derive stellar masses for all Cl 1604 members. The colors and stellar masses of the K+A galaxies support the idea that they are progenitors of red sequence galaxies. Their morphologies, residual star formation rates, and spatial distributions suggest that galaxy mergers may be the principal mechanism producing post-starburst galaxies. Interaction between galaxies and the dense intracluster medium (ICM) is also effective, but only in the cores of dynamically evolved clusters. The prevalence of post-starburst galaxies in clusters correlates with the dynamical state of the host cluster, as both galaxy mergers and the dense ICM produce post-starburst galaxies. We also investigate the incompleteness and contamination of K+A samples selected by means of H\u03b4 and [O II] equivalent widths. K+A samples may be up to ~50% incomplete due to the presence of LINERs/Seyferts, and up to ~30% of K+A galaxies could have substantial star formation activity.", "doi": "10.1088/0004-637X/792/1/16", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2014-09-01", "series_number": "1", "volume": "792", "issue": "1", "pages": "Art. No. 16" }, { "id": "authors:5s9ze-vk766", "collection": "authors", "collection_id": "5s9ze-vk766", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140808-092834351", "type": "article", "title": "The violent youth of bright and massive cluster galaxies and their maturation over 7 billion years", "author": [ { "family_name": "Acaso", "given_name": "B.", "clpid": "Acaso-B" }, { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "Rumbaugh", "given_name": "N.", "clpid": "Rumbaugh-N" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "In this study, we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift (z \u223c 0.9), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift (z \u223c 0.1) counterparts drawn from the MCXC meta-catalogue, supplemented by Sloan Digital Sky Survey imaging and spectroscopy. We observed striking differences in the morphological, colour, spectral, and stellar mass properties of the BCGs/MMCGs in the two samples. High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies, with blue broad-band colours, properties largely absent amongst the low-redshift BCGs/MMCGs. The stellar mass of BCGs was found to increase by an average factor of 2.51 \u00b1 0.71 from z \u223c 0.9 to z \u223c 0.1. Through this and other comparisons, we conclude that a combination of major merging (mainly wet or mixed) and in situ star formation are the main mechanisms which build stellar mass in BCGs/MMCGs. The stellar mass growth of the BCGs/MMCGs also appears to grow in lockstep with both the stellar baryonic and total mass of the cluster. Additionally, BCGs/MMCGs were found to grow in size, on average, a factor of \u223c3, while their average S\u00e9rsic index increased by \u223c0.45 from z \u223c 0.9 to z \u223c 0.1, also supporting a scenario involving major merging, though some adiabatic expansion is required. These observational results are compared to both models and simulations to further explore the implications on processes which shape and evolve BCGs/MMCGs over the past \u223c7 Gyr.", "doi": "10.1093/mnras/stu877", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2014-07-21", "series_number": "1", "volume": "442", "issue": "1", "pages": "589-615" }, { "id": "authors:v34dz-f3505", "collection": "authors", "collection_id": "v34dz-f3505", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130222-141228689", "type": "article", "title": "The X-Ray-Optical Relations for Nine Clusters at z = 0.7-1.1 from the ORELSE Survey", "author": [ { "family_name": "Rumbaugh", "given_name": "N.", "clpid": "Rumbaugh-N" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Fassnacht", "given_name": "C. D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We use Chandra observations of nine optically and X-ray-selected clusters in five different structures at z ~ 0.7-1.1 from the Observations of Redshift Evolution in Large-Scale Environments survey to study diffuse X-ray emission from galaxy clusters. X-ray gas temperatures and bolometric rest-frame luminosities are measured for each cluster in the sample. We present new redshift measurements, derived from data obtained using the Deep Imaging Multi-Object Spectrograph on the Keck 10 m telescope, for two clusters in the RX J0910 supercluster at z ~ 1.1, from which velocity dispersions are measured. Dispersions for all clusters are combined with X-ray luminosities and gas temperatures to evaluate how the cluster properties compare to low-redshift scaling relations. We also measure the degree of substructure in each cluster by examining the velocity histograms, performing Dressler-Shectman tests, and computing the offsets between the X-ray emission center and optically derived centroids. We find that only two clusters show clear indications of being unrelaxed, based on their scaling relations and other dynamical state diagnostics. Using our sample, we evaluate the redshift evolution of the Lx -T relation and investigate the implications of our results for precision cosmology surveys.", "doi": "10.1088/0004-637X/763/2/124", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2013-02-01", "series_number": "2", "volume": "763", "issue": "2", "pages": "Art. No. 124" }, { "id": "authors:nm2tg-vsq39", "collection": "authors", "collection_id": "nm2tg-vsq39", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120321-101653524", "type": "article", "title": "The Evolution and Environments of X-Ray Emitting Active Galactic Nuclei in High-redshift Large-scale Structures", "author": [ { "family_name": "Rumbaugh", "given_name": "N.", "clpid": "Rumbaugh-N" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Fassnacht", "given_name": "C. D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "McGrath", "given_name": "E. J.", "clpid": "McGrath-E-J" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We use deep Chandra imaging and an extensive optical spectroscopy campaign on the Keck 10 m telescopes to study the properties of X-ray point sources in two isolate d X-ray-selected clusters, two superclusters, and one \"supergroup\" at redshifts of z ~ 0.7-0.9. We first study X-ray point sources using the statistical measure of cumulative source counts, finding that the measured overdensities are consistent with previous results, but we recommend caution in overestimating the precision of the technique. Optical spectroscopy of objects matched to X-ray point sources confirms a total of 27 active galactic nuclei (AGNs) within 5 structures, and we find that their host galaxies tend to be located away from dense cluster cores. More than 36% of the host galaxies are located in the \"green valley\" on a color-magnitude diagram, which suggests they are a transitional population. Based on analysis of [O II] and H\u03b4 line strengths, the average spectral properties of the AGN host galaxies in all structures indicate either ongoing star formation or a starburst within ~1 Gyr, and that the host galaxies are younger than the average galaxy in the parent population. These results indicate a clear connection between starburst and nuclear activity. We use composite spectra of the spectroscopically confirmed members in each structure (cluster, supergroup, or supercluster) to separate them based on a measure of the overall evolutionary state of their constituent galaxies. We define structures as having more evolved populations if their average galaxy has lower EW([O II]) and EW(H\u03b4). The AGNs in the more evolved structures have lower rest-frame 0.5-8 keV X-ray luminosities (all below 10^(43.3) erg s^(\u20131)) and longer times since a starburst than those in the unevolved structures, suggesting that the peak of both star formation and AGN activity has occurred at earlier times. With the wide range of evolutionary states and time frames in the structures, we use our results to analyze the evolution of X-ray AGNs and evaluate potential triggering mechanisms.", "doi": "10.1088/0004-637X/746/2/155", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2012-02-20", "series_number": "2", "volume": "746", "issue": "2", "pages": "155" }, { "id": "authors:s6drm-ypt19", "collection": "authors", "collection_id": "s6drm-ypt19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120323-084333613", "type": "article", "title": "The Assembly of the Red Sequence at z ~ 1: The Color and Spectral Properties of Galaxies in the Cl1604 Supercluster", "author": [ { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "Fassnacht", "given_name": "C. D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "McGrath", "given_name": "E. J.", "clpid": "McGrath-E-J" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" }, { "family_name": "Surace", "given_name": "J. A.", "orcid": "0000-0001-7291-0087", "clpid": "Surace-J-A" }, { "family_name": "Lacy", "given_name": "M.", "orcid": "0000-0002-3032-1783", "clpid": "Lacy-M" } ], "abstract": "We investigate the properties of the 525 spectroscopically confirmed members of the Cl1604 supercluster at z ~ 0.9 as part of the Observations of Redshift Evolution in Large Scale Environments survey. In particular, we focus on the photometric, stellar mass, morphological, and spectral properties of the 305 member galaxies of the eight clusters and groups that comprise the Cl1604 supercluster. Using an extensive Keck Low-Resolution Imaging Spectrometer (LRIS)/DEep Imaging Multi-Object Spectrograph (DEIMOS) spectroscopic database in conjunction with ten-band ground-based, Spitzer, and Hubble Space Telescope imaging, we investigate the buildup of the red sequence in groups and clusters at high redshift. Nearly all of the brightest and most massive red-sequence galaxies present in the supercluster environment are found to lie within the bounds of the cluster and group systems, with a surprisingly large number of such galaxies present in low-mass group systems. Despite the prevalence of these red-sequence galaxies, we find that the average cluster galaxy has a spectrum indicative of a star-forming galaxy, with a star formation rate between those of z ~ 1 field galaxies and moderate-redshift cluster galaxies. The average group galaxy is even more active, exhibiting spectral properties indicative of a starburst. The presence of massive, red galaxies and the high fraction of starbursting galaxies present in the group environment suggest that significant processing is occurring in group environments at z ~ 1 and earlier. There is a deficit of low-luminosity red-sequence galaxies in all Cl1604 clusters and groups, suggesting that such galaxies transition to the red sequence at later times. Extremely massive (~10^(12)M_\u2609) red-sequence galaxies routinely observed in rich clusters at z ~ 0 are also absent from the Cl1604 clusters and groups. We suggest that such galaxies form at later times through merging processes. There are significant populations of transition galaxies at intermediate stellar masses (log(M_*)=10.25-10.75) present in the group and cluster environments, suggesting that this range is important for the buildup of the red-sequence mass function at z ~ 1. Through a comparison of the transitional populations present in the Cl1604 cluster and group systems, we find evidence that massive blue-cloud galaxies are quenched earliest in the most dynamically relaxed systems and at progressively later times in dynamically unrelaxed systems.", "doi": "10.1088/0004-637X/745/2/106", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2012-02-01", "series_number": "2", "volume": "745", "issue": "2", "pages": "Art. No. 106" }, { "id": "authors:pdd79-0ea56", "collection": "authors", "collection_id": "pdd79-0ea56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111003-085429423", "type": "article", "title": "The Origin of [O II] Emission in Recently Quenched Active Galaxy Nucleus Hosts", "author": [ { "family_name": "Kocevski", "given_name": "Dale D.", "clpid": "Kocevski-D-D" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Shapley", "given_name": "Alice E.", "orcid": "0000-0003-3509-4855", "clpid": "Shapley-A-E" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Squires", "given_name": "Gordon K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We have employed emission-line diagnostics derived from DEIMOS and NIRSPEC spectroscopy to determine the origin of the [O II] emission line observed in six active galactic nucleus (AGN) hosts at z ~ 0.9. These galaxies are a subsample of AGN hosts detected in the Cl1604 supercluster that exhibit strong Balmer absorption lines in their spectra and appear to be in a post-starburst or post-quenched phase, if not for their [O II] emission. Examining the flux ratio of the [N II] to H\u03b1 lines, we find that in five of the six hosts the dominant source of ionizing flux is AGN continuum emission. Furthermore, we find that four of the six galaxies have over twice the [O II] line luminosity that could be generated by star formation alone given their H\u03b1 line luminosities. This strongly suggests that AGN-excited narrow-line emission is contaminating the [O II] line flux. A comparison of star formation rates calculated from extinction-corrected [O II] and H\u03b1 line luminosities indicates that the former yields a five-fold overestimate of the current activity in these galaxies. Our findings reveal the [O II] line to be a poor indicator of star formation activity in a majority of these moderate-luminosity Seyferts. This result bolsters our previous findings that an increased fraction of AGN at high redshifts is hosted by galaxies in a post-starburst phase. The relatively high fraction of AGN hosts in the Cl1604 supercluster that show signs of recently truncated star formation activity may suggest that AGN feedback plays an increasingly important role in suppressing ongoing activity in large-scale structures at high redshift.", "doi": "10.1088/2041-8205/737/2/L38", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2011-08-20", "series_number": "2", "volume": "737", "issue": "2", "pages": "Art. No. L38" }, { "id": "authors:52gft-4w772", "collection": "authors", "collection_id": "52gft-4w772", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100625-151226641", "type": "article", "title": "The Origin of [O II] in Post-starburst and Red-sequence Galaxies in High-redshift Clusters", "author": [ { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Shapley", "given_name": "A.", "orcid": "0000-0003-3509-4855", "clpid": "Shapley-A-E" }, { "family_name": "Kocevski", "given_name": "D.", "clpid": "Kocevski-D" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We present the first results from a near-IR spectroscopic campaign of the Cl1604 supercluster at z ~ 0.9 and the cluster RX J1821.6+6827 at z ~ 0.82 to investigate the nature of [O II] \u03bb3727 emission in cluster galaxies at high redshift. Of the 401 members in Cl1604 and RX J1821+6827 confirmed using the Keck II/DEIMOS spectrograph, 131 galaxies have detectable [O II] emission with no other signs of current star formation activity, as well as strong absorption features indicative of a well-established older stellar population. The combination of these features suggests that the primary source of [O II] emission in these galaxies is not a result of star formation processes, but rather due to the presence of a low-ionization nuclear emission-line region (LINER) or Seyfert component. Using the NIRSPEC spectrograph on the Keck II 10 m telescope, 19 such galaxies were targeted, as well as 6 additional [O II]-emitting cluster members that exhibited signs of ongoing star formation activity. Nearly half (~47%) of the 19 [O II]-emitting, absorption-line-dominated galaxies exhibit [O II] to H\u03b1 equivalent width (EW) ratios higher than unity, the typical observed value for star-forming galaxies, with an EW distribution similar to that observed for LINERs at low redshift. A majority (~68%) of these 19 galaxies are classified as LINER/Seyfert based primarily on the emission-line ratio of [N II] \u03bb6584 and H\u03b1. The fraction of LINER/Seyferts increases to ~85% for red [O II]-emitting, absorption-line-dominated galaxies. The LINER/Seyfert galaxies in our Cl1604 sample exhibit average L([O II])/L(H\u03b1) ratios that are significantly higher than that observed in populations of star-forming galaxies, suggesting that [O II] is a poor indicator of star formation in a significant fraction of high-redshift cluster members. From the prevalence of [O II]-emitting, absorption-line-dominated galaxies in both systems and the fraction of such galaxies that are classified as LINER/Seyfert, we estimate that at least ~20% of galaxies in high-redshift clusters with M_* > 10^(10)-10^(10.5) M_\u2299 contain a LINER/Seyfert component that can be revealed with line ratios. We also investigate the effect such a population has on the global star formation rate of cluster galaxies and the post-starburst fraction, concluding that LINER/Seyferts must be accounted for if these quantities are to be physically meaningful.", "doi": "10.1088/0004-637X/716/2/970", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2010-06-20", "series_number": "2", "volume": "716", "issue": "2", "pages": "970-992" }, { "id": "authors:04v0c-0sm89", "collection": "authors", "collection_id": "04v0c-0sm89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091001-145047971", "type": "article", "title": "No Evidence of Quasar-Mode Feedback in a Four-Way Group Merger at z ~ 0.84", "author": [ { "family_name": "Kocevski", "given_name": "Dale D.", "clpid": "Kocevski-D-D" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Fassnacht", "given_name": "Christopher D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Squires", "given_name": "Gordon K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We report on the results of a Chandra search for evidence of triggered nuclear activity within the Cl0023+0423 four-way group merger at z ~ 0.84. The system consists of four interacting galaxy groups in the early stages of hierarchical cluster formation and, as such, provides a unique look at the level of processing and evolution already under way in the group environment prior to cluster assembly. We present the number counts of X-ray point sources detected in a field covering the entire Cl0023 structure, as well as a cross-correlation of these sources with our extensive spectroscopic database. Both the redshift distribution and cumulative number counts of X-ray sources reveal little evidence to suggest that the system contains X-ray luminous active galactic nuclei (AGNs) in excess to what is observed in the field population. If preprocessing is under way in the Cl0023 system, our observations suggest that powerful nuclear activity is not the predominant mechanism quenching star formation and driving the evolution of Cl0023 galaxies. We speculate that this is due to a lack of sufficiently massive nuclear black holes required to power such activity, as previous observations have found a high late-type fraction among the Cl0023 population. It may be that disruptive AGN-driven outflows become an important factor in the preprocessing of galaxy populations only during a later stage in the evolution of such groups and structures when sufficiently massive galaxies (and central black holes) have built up, but prior to hydrodynamical processes stripping them of their gas reservoirs.", "doi": "10.1088/0004-637X/703/1/L33", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2009-09-20", "series_number": "1", "volume": "703", "issue": "1", "pages": "L33-L36" }, { "id": "authors:6c6hq-52f03", "collection": "authors", "collection_id": "6c6hq-52f03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090916-135340742", "type": "article", "title": "Properties of Galaxies Hosting X-ray-selected Active Galactic Nuclei in the CL1604 Supercluster at z = 0.9", "author": [ { "family_name": "Kocevski", "given_name": "Dale D.", "clpid": "Kocevski-D-D" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Fassnacht", "given_name": "Christopher D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Lin", "given_name": "Robin", "clpid": "Lin-R" }, { "family_name": "Squires", "given_name": "Gordon K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "Recent galaxy evolution models suggest that feedback from active galactic nuclei (AGNs) may be responsible for suppressing star formation in their host galaxies and the subsequent migration of these systems onto the red sequence. To investigate the role of AGNs in driving the evolution of their hosts, we have carried out a study of the environments and optical properties of galaxies harboring X-ray luminous AGNs in the Cl1604 supercluster at z ~ 0.9. Making use of Chandra, HST/ACS and Keck/DEIMOS observations, we examine the integrated colors, morphologies, and spectral properties of nine moderate-luminosity (L_X ~ 10^(43) erg s^(\u20131)) type 2 Seyferts detected in the Cl1604 complex. We find that the AGNs are predominantly hosted by luminous spheroids and/or bulge-dominated galaxies which have colors that place them in the valley between the blue cloud and red sequence in color-magnitude space, consistent with predictions that AGN hosts should constitute a transition population. Half of the hosts have bluer overall colors as a result of blue resolved cores in otherwise red spheroids and a majority show signs of recent or pending interactions. We also find a substantial number exhibit strong Balmer absorption features indicative of post-starburst galaxies, despite the fact that we detect narrow [O II] emission lines in all of the host spectra. If the [O II] lines are due in part to AGN emission, as we suspect, then this result implies that a significant fraction of these galaxies (44%) have experienced an enhanced level of star formation within the last ~1 Gyr which was rapidly suppressed. Furthermore we observe that the hosts galaxies tend to avoid the densest regions of the supercluster and are instead located in intermediate density environments, such as the infall region of a massive cluster or in poorer systems undergoing assembly. Overall we find that the properties of the nine host galaxies are generally consistent with a scenario in which recent interactions have triggered both increased levels of nuclear activity and an enhancement of centrally concentrated star formation, followed by a rapid truncation of the latter, possibly as a result of feedback from the AGN itself. Our finding that the hosts of moderate-luminosity AGNs within the Cl1604 supercluster are predominantly a transition population suggests that AGN feedback may play an important role in accelerating galaxy evolution in large-scale structures.", "doi": "10.1088/0004-637X/700/2/901", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2009-08-01", "series_number": "2", "volume": "700", "issue": "2", "pages": "901-914" }, { "id": "authors:mmhh9-h5s19", "collection": "authors", "collection_id": "mmhh9-h5s19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090910-115058998", "type": "article", "title": "Serendipitous Discovery of an Overdensity of Ly\u03b1 Emitters at z ~ 4.8 in the CL1604 Supercluster Field", "author": [ { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Sawicki", "given_name": "M.", "orcid": "0000-0002-7712-7857", "clpid": "Sawicki-M" }, { "family_name": "Martin", "given_name": "C.", "orcid": "0000-0002-8650-1644", "clpid": "Martin-D-Christopher" }, { "family_name": "Lagattuta", "given_name": "D. J.", "clpid": "Lagattuta-D-J" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Kocevski", "given_name": "D.", "clpid": "Kocevski-D" }, { "family_name": "Fassnacht", "given_name": "C. D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We present results of a spectroscopic search for Ly\u03b1 emitters (LAEs) in the Cl1604 supercluster field using the extensive spectroscopic Keck/DEep Imaging Multi-Object Spectrograph database taken as part of the Observations of Redshift Evolution in Large-Scale Environments survey. A total of 12 slitmasks were observed and inspected in the Cl1604 field, spanning a survey volume of 1.365 \u00d7 10^4 comoving Mpc^3. We find a total of 17 high-redshift (4.39 \u2264 z \u2264 5.67) LAE candidates down to a limiting flux of 1.9 \u00d7 10^(\u201318) erg s^(\u20131) cm^(\u20132) (L(Ly\u03b1) = 4.6 \u00d7 10^(41) erg s^(\u20131) or ~0.1 L _* at z ~ 5), 13 of which we classify as high quality. The resulting LAE number density is nearly double that of LAEs found in the Subaru deep field at z ~ 4.9 and nearly an order of magnitude higher than in other surveys of LAEs at similar redshifts, an excess that is essentially independent of LAE luminosity. We also report on the discovery of two possible LAE group structures at z ~ 4.4 and z ~ 4.8 and investigate the effects of cosmic variance of LAEs on our results. Fitting a simple truncated single Gaussian model to a composite spectrum of the 13 high-quality LAE candidates, we find a best-fit stellar velocity dispersion of 136 km s^(\u20131). Additionally, we see modest evidence of a second peak in the composite spectrum, possibly caused by galactic outflows, offset from the main velocity centroid of the LAE population by ~440 km s^(\u20131) as well as evidence for a nontrivial Ly\u03b1 escape fraction. We find an average star formation rate density (SFRD) of ~5 \u00d7 10^(\u20133) M_\u2609 yr^(\u20131) Mpc^(\u20133) with moderate evidence for negative evolution in the SFRD from z ~ 4.6 to z ~ 5.7. By simulating the statistical flux loss due to our observational setup, we measure a best-fit luminosity function characterized by \u03a6_* L_* = 2.2^(+3.9)_(\u20131.3) \u00d7 10^(39) erg s^(\u20131) Mpc^(\u20133) for \u03b1 = \u20131.6, generally consistent with measurements from other surveys at similar epochs. Finally, we investigate any possible effects from weak or strong gravitational lensing induced by the foreground supercluster, finding that our LAE candidates are minimally affected by lensing processes.", "doi": "10.1088/0004-637X/700/1/20", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2009-07-20", "series_number": "1", "volume": "700", "issue": "1", "pages": "20-48" }, { "id": "authors:1gkx5-ae392", "collection": "authors", "collection_id": "1gkx5-ae392", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090803-135140038", "type": "article", "title": "The Observations of Redshift Evolution in Large-Scale Environments (ORELSE) Survey. I. The Survey Design and First Results on CL 0023+0423 at z = 0.84 and RX J1821.6+6827 at z = 0.82", "author": [ { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Kocevski", "given_name": "D. D.", "clpid": "Kocevski-D-D" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We present the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) Survey, a systematic search for structure on scales greater than 10 h^(\u20131)_70 Mpc around 20 well-known clusters at redshifts of 0.6 < z < 1.3. The goal of the survey is to examine a statistical sample of dynamically active clusters and large-scale structures in order to quantify galaxy properties over the full range of local and global environments. We describe the survey design, the cluster sample, and our extensive observational data covering at least 25' around each target cluster. We use adaptively smoothed red galaxy density maps from our wide-field optical imaging to identify candidate groups/clusters and intermediate-density large-scale filaments/walls in each cluster field. Because photometric techniques (such as photometric redshifts, statistical overdensities, and richness estimates) can be highly uncertain, the crucial component of this survey is the unprecedented amount of spectroscopic coverage. We are using the wide-field, multiobject spectroscopic capabilities of the Deep Multiobject Imaging Spectrograph to obtain 100-200+ confirmed cluster members in each field. Our survey has already discovered the Cl 1604 supercluster at z \u2248 0.9, a structure which contains at least eight groups and clusters and spans 13 Mpc \u00d7 100 Mpc. Here, we present the results on the large-scale environments of two additional clusters, Cl 0023+0423 at z = 0.84 and RX J1821.6+6827 at z = 0.82, which highlight the diversity of global properties at these redshifts. The optically selected Cl 0023+0423 is a four-way group-group merger with constituent groups having measured velocity dispersions between 206 and 479 km s^\u20131. The galaxy population is dominated by blue, star-forming galaxies, with 80% of the confirmed members showing [O II] emission. The strength of the H\u03b4 line in a composite spectrum of 138 members indicates a substantial contribution from recent starbursts to the overall galaxy population. In contrast, the X-ray-selected RX J1821.6+6827 is a largely isolated, massive cluster with a measured velocity dispersion of 926 \u00b1 77 km s^(\u20131). The cluster exhibits a well-defined red sequence with a large quiescent galaxy population. The results from these two targets, along with preliminary findings on other ORELSE clusters, suggest that optical selection may be more effective than X-ray surveys at detecting less-evolved, dynamically active systems at these redshifts.", "doi": "10.1088/0004-6256/137/6/4867", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2009-06", "series_number": "6", "volume": "137", "issue": "6", "pages": "4867-4883" }, { "id": "authors:9kvjr-fzy69", "collection": "authors", "collection_id": "9kvjr-fzy69", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:GALaj09", "type": "article", "title": "The Northern Sky Optical Cluster Survey. III. A Cluster Catalog Covering PI Steradians", "author": [ { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Lopes", "given_name": "P. A. A.", "clpid": "Lopes-P-A-A" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Kohl-Moreira", "given_name": "J. L.", "clpid": "Kohl-Moreira-J-L" }, { "family_name": "Capelato", "given_name": "H. V.", "clpid": "Capelato-H-V" }, { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" } ], "abstract": "We present the complete galaxy cluster catalog from the Northern Sky Optical Cluster Survey, a new, objectively defined catalog of candidate galaxy clusters at z \u227e 0.25 drawn from the Digitized Second Palomar Observatory Sky Survey (DPOSS). The data presented here cover the Southern Galactic Cap, as well as the less well-calibrated regions of the Northern Galactic Cap. In addition, due to improvements in our cluster finder and measurement methods, we provide an updated catalog for the well-calibrated Northern Galactic Cap region previously published in Paper II. The complete survey covers 11,411 deg^2, with over 15,000 candidate clusters. We discuss improved photometric redshifts, richnesses, and optical luminosities which are provided for each cluster. A variety of substructure measures are computed for a subset of over 11,000 clusters. We also discuss the derivation of dynamical radii r 200 and its relation to cluster richness. A number of consistency checks between the three areas of the survey are also presented, demonstrating the homogeneity of the catalog over disjoint sky areas. We perform extensive comparisons to existing optically and X-ray-selected cluster catalogs, and derive new X-ray luminosities and temperatures for a subset of our clusters. We find that the optical and X-ray luminosities are well correlated, even using relatively shallow ROSAT All Sky Survey and DPOSS data. This survey provides a good comparison sample to the MaxBCG catalog based on Sloan Digital Sky Survey Data, and complements that survey at low redshifts 0.07 < z < 0.1.", "doi": "10.1088/0004-6256/137/2/2981", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2009-02", "series_number": "2", "volume": "137", "issue": "2", "pages": "2981-2999" }, { "id": "authors:4p1a7-k4517", "collection": "authors", "collection_id": "4p1a7-k4517", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:GALRRapj08", "type": "article", "title": "The Complex Structure of the Cl 1604 Supercluster at z ~ 0.9", "author": [ { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Lemaux", "given_name": "B. C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "Kocevski", "given_name": "D.", "clpid": "Kocevski-D-D" }, { "family_name": "Squires", "given_name": "G. K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "The Cl 1604 supercluster at z = 0.9 is one of a small handful of such structures discovered in the high-redshift universe and is the first target observed as part of the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. To date, Cl 1604 is the largest structure mapped at z ~ 1, with the most constituent clusters and the largest number of spectroscopically confirmed member galaxies. In this paper we present the results of a spectroscopic campaign to create a three-dimensional map of Cl 1604 and to understand the contamination by foreground and background large-scale structures. Combining new Deep Imaging Multi-Object Spectrograph observations with previous data yields high-quality redshifts for 1138 extragalactic objects in a ~0.08 deg^2 region, 413 of which are supercluster members. We examine the complex three-dimensional structure of Cl 1604, providing velocity dispersions for eight of the member clusters and groups. Our extensive spectroscopic data set is used to examine potential biases in cluster velocity dispersion measurements in the presence of overlapping structures and filaments. We also discuss other structures found along the line of sight, including a filament at z = 0.6 and two serendipitously discovered groups at z ~ 1.2.", "doi": "10.1086/590416", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2008-09-10", "series_number": "2", "volume": "684", "issue": "2", "pages": "933-956" }, { "id": "authors:wyhbb-j0387", "collection": "authors", "collection_id": "wyhbb-j0387", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:KOCapj09", "type": "article", "title": "Chandra Observations of the cl1604 Supercluster at z = 0.9: Evidence for an Overdensity of Active Galactic Nuclei", "author": [ { "family_name": "Kocevski", "given_name": "Dale D.", "clpid": "Kocevski-D-D" }, { "family_name": "Lubin", "given_name": "Lori M.", "clpid": "Lubin-L-M" }, { "family_name": "Gal", "given_name": "Roy", "clpid": "Gal-R-R" }, { "family_name": "Lemaux", "given_name": "Brian C.", "orcid": "0000-0002-1428-7036", "clpid": "Lemaux-B-C" }, { "family_name": "Fassnacht", "given_name": "Christopher D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Squires", "given_name": "Gordon K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" } ], "abstract": "We present the results of Chandra observations of the Cl1604 supercluster at z ~ 0.9. The system is the largest structure mapped at redshifts approaching unity, containing at least eight spectroscopically confirmed galaxy clusters and groups. Using two 50 ks ACIS-I pointings we examine both the X-ray point-source population and the diffuse emission from individual clusters in the system. Over an area encompassing the entire supercluster (~0.154 deg2), we find a 2.5\u03c3 excess of point sources detected in the hard band (2-10 keV) relative to the number of sources found in blank fields observed by Chandra. No such excess is observed in the soft band (0.5-2 keV). The hard-band source density is 1.47 times greater than that of a blank field, in agreement with the previously reported correlation between overdensity amplitude and cluster redshift. Using a maximum likelihood technique, we have matched 112 of the 161 detected X-ray point sources to optical counterparts and found 15 sources that are associated with the supercluster. All 15 sources have rest-frame luminosities consistent with emission from active galactic nuclei (AGNs). We find that the supercluster AGNs largely avoid the densest regions of the system and are instead distributed on the outskirts of massive clusters or within poorer clusters and groups. We have also detected diffuse emission from two of the eight clusters and groups in the system, clusters Cl1604 + 4304 and Cl1604 + 4314. The systems have bolometric luminosities of 1.43 \u00d7 10^44 and 8.20 \u00d7 10^43 h70^\u20132 erg s^\u20131 and gas temperatures of 3.50+1.82 \u20131.08 and 1.64+0.65 \u20130.45 keV, respectively. Using updated velocity dispersions, we compare the properties of these systems with the cluster scaling relations followed by other X-rays and optically selected galaxy clusters at high redshift.", "doi": "10.1088/0004-637X/690/1/295", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2008-01-01", "series_number": "1", "volume": "690", "issue": "1", "pages": "295-318" }, { "id": "authors:szbzg-s2w11", "collection": "authors", "collection_id": "szbzg-s2w11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110721-100440243", "type": "article", "title": "X-Ray Galaxy Clusters in NoSOCS: Substructure and the Correlation of Optical and X-Ray Properties", "author": [ { "family_name": "Lopes", "given_name": "P. A. A.", "clpid": "Lopes-P-A-A" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Capelato", "given_name": "H. V.", "clpid": "Capelato-H-V" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Brunner", "given_name": "R. J.", "clpid": "Brunner-R-J" }, { "family_name": "Odewahn", "given_name": "S. C.", "clpid": "Odewahn-S-C" }, { "family_name": "Mahabal", "given_name": "A. A.", "orcid": "0000-0003-2242-0244", "clpid": "Mahabal-A-A" } ], "abstract": "We present a comparison of optical and X-ray properties of galaxy clusters in the northern sky, using literature data from BAX and optically selected clusters in DPOSS. We determine the recovery rate of X-ray-detected clusters in the optical as a function of richness, redshift, and X-ray luminosity, showing that the missed clusters are typically low-contrast systems when observed optically (either poor or at high redshifts). We employ four different statistical tests to test for the presence of substructure using optical two-dimensional data. We find that approximately 35% of the clusters show strong signs of substructure in the optical. However, the results are test-dependent, with variations also due to the magnitude range and radius utilized. We have also performed a comparison of X-ray luminosity and temperature with optical galaxy counts (richness). We find that the slope and scatter of the relations between richness and the X-ray properties are heavily dependent on the density contrast of the clusters. The selection of substructure-free systems does not improve the correlation between X-ray luminosity and richness, but this comparison also shows much larger scatter than one obtained using the X-ray temperature. In the latter case, the sample is significantly reduced because temperature measurements are available only for the most massive (and thus high-contrast) systems. However, the comparison between temperature and richness is very sensitive to the exclusion of clusters showing signs of substructure. The correlation of X-ray luminosity and richness is based on the largest sample to date (~750 clusters), while tests involving temperature use a similar number of objects as previous works (\u227e100). The results presented here are in good agreement with existing literature.", "doi": "10.1086/505630", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2006-09-01", "series_number": "1", "volume": "648", "issue": "1", "pages": "209-229" }, { "id": "authors:9zvrf-f9p35", "collection": "authors", "collection_id": "9zvrf-f9p35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110228-095111016", "type": "article", "title": "Mass along the Line of Sight to the Gravitational Lens B1608+656: Galaxy Groups and Implications for H_0", "author": [ { "family_name": "Fassnacht", "given_name": "C. D.", "orcid": "0000-0002-4030-5461", "clpid": "Fassnacht-C-D" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Lubin", "given_name": "L. M.", "clpid": "Lubin-L-M" }, { "family_name": "McKean", "given_name": "J. P.", "clpid": "McKean-J-P" }, { "family_name": "Squires", "given_name": "Gordon K.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" }, { "family_name": "Readhead", "given_name": "A. C. S.", "orcid": "0000-0001-9152-961X", "clpid": "Readhead-A-C-S" } ], "abstract": "We report the discovery of four groups of galaxies along the line of sight to the B1608+656 gravitational lens system. One group is at the redshift of the primary lensing galaxy (z = 0.631) and appears to have a low mass, with eight spectroscopically confirmed members and an estimated velocity dispersion of 150 \u00b1 60 km s^(-1). The three other groups are in the foreground of the lens. These groups contain ~10 confirmed members each and are located at redshifts of 0.265, 0.426, and 0.52. Two of the three additional groups are centered roughly on the lens system, while the third is centered ~1' south of the lens. We investigate the effect of each of the four groups on the gravitational lensing potential of the B1608+656 system, with a particular focus on the implications for the value of H_0 derived from this system. We find that each group provides an external convergence of ~0.005-0.060, depending on the assumptions made in the calculation. For the B1608+656 system, the stellar velocity dispersion of the lensing galaxy has been measured, thus breaking the mass sheet degeneracy due to the group that is physically associated with the lens. The effect of the other groups along the line of sight can be folded into the overall uncertainties due to large-scale structure (LSS) along the line of sight. Because B1608+656 appears to lie along an overdense line of sight, the LSS will cause the measurement of H_0 to be biased high for this system. This effect could be 5% or greater.", "doi": "10.1086/500927", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2006-05-01", "series_number": "1", "volume": "642", "issue": "1", "pages": "30-38" }, { "id": "authors:wfh33-w9f25", "collection": "authors", "collection_id": "wfh33-w9f25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190722-133357882", "type": "article", "title": "Morphology of low-redshift compact galaxy clusters -- I. Shapes and radial profiles", "author": [ { "family_name": "Strazzullo", "given_name": "V.", "clpid": "Strazzullo-V" }, { "family_name": "Paolillo", "given_name": "M.", "orcid": "0000-0003-4210-7693", "clpid": "Paolillo-M" }, { "family_name": "Longo", "given_name": "G.", "orcid": "0000-0002-9182-8414", "clpid": "Longo-G" }, { "family_name": "Puddu", "given_name": "E.", "clpid": "Puddu-E" }, { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" } ], "abstract": "The morphology of clusters of galaxies may be described with a set of parameters which contain information concerning the formation and evolutionary history of these systems. In this paper we present a preliminary study of the morphological parameters of a sample of 28 compact Abell clusters extracted from Digitized Palomar Sky Survey data, measured with a procedure based on the use of the CIAO-SHERPA software, developed at the Centre for Astrophysics for X-ray data analysis. The morphology of galaxy clusters is parametrized by their apparent ellipticity, position angle of the major axis, centre coordinates, core radius and \u03b2-model power-law index. Our procedure provides estimates of these parameters (and of the related uncertainties) by simultaneously fitting them all, overcoming some of the difficulties induced by sparse data and low-number statistics typical of this kind of analysis. The cluster parameters were fitted in a 6 \u00d7 6 Mpc^2 region, measuring the background in a 4 < R < 5 Mpc annulus. We also explore the correlations between shape and profile parameters and other cluster properties. Our results can be summarized as follows: one-third of this compact cluster sample has core radii smaller than 100 kpc, i.e. near the limit that our data allow us to resolve, possibly consistent with cusped models. The remaining clusters span a broad range of core radii up to \u223c1500 kpc, including some apparently regular clusters with well-resolved core radii. More than 80 per cent of this sample has ellipticity higher than 0.2. The alignment between the cluster and the major axis of the dominant galaxy is confirmed at a high significance level, while no correlation is observed with other bright cluster members. No significant correlation is found between cluster richness and ellipticity. Instead, cluster richness is found to correlate, albeit with large scatter, with the cluster core radius. Finally, in contrast to claims in previous works, a flat universe seems to be favoured, and in any case is not excluded, by the power-law index \u03b2 of our number density profiles.", "doi": "10.1111/j.1365-2966.2005.08880.x", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2005-05-01", "series_number": "1", "volume": "359", "issue": "1", "pages": "191-210" }, { "id": "authors:f4n80-adt46", "collection": "authors", "collection_id": "f4n80-adt46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191002-142815408", "type": "article", "title": "Peculiar Broad Absorption Line Quasars Found in The Digitized Palomar Observatory Sky Survey", "author": [ { "family_name": "Brunner", "given_name": "Robert J.", "clpid": "Brunner-R-J" }, { "family_name": "Hall", "given_name": "Patrick B.", "clpid": "Hall-P-B" }, { "family_name": "Djorgovski", "given_name": "S. George", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Mahabal", "given_name": "A. A.", "orcid": "0000-0003-2242-0244", "clpid": "Mahabal-A-A" }, { "family_name": "Lopes", "given_name": "P. A. A.", "clpid": "Lopes-P-A-A" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Odewahn", "given_name": "S. C.", "clpid": "Odewahn-S-C" }, { "family_name": "Castro", "given_name": "S.", "clpid": "Castro-S" }, { "family_name": "Thompson", "given_name": "D.", "clpid": "Thompson-D" }, { "family_name": "Chaffee", "given_name": "F.", "clpid": "Chaffee-F-H" }, { "family_name": "Darling", "given_name": "J.", "orcid": "0000-0003-2511-2060", "clpid": "Darling-J" }, { "family_name": "Desai", "given_name": "V.", "orcid": "0000-0002-1340-0543", "clpid": "Desai-V" } ], "abstract": "With the recent release of large (i.e., \u2273100 million objects), well-calibrated photometric surveys, such as Digitized Palomar Observatory Sky Survey (DPOSS), Two Micron All Sky Survey, and Sloan Digital Sky Survey, spectroscopic identification of important targets is no longer a simple issue. In order to enhance the returns from a spectroscopic survey, candidate sources are often preferentially selected to be of interest, such as brown dwarfs or high-redshift quasars. This approach, while useful for targeted projects, risks missing new or unusual species. We have, as a result, taken the alternative path of spectroscopically identifying interesting sources with the sole criterion being that they are in low-density areas of the g-r and r-i color space defined by DPOSS. In this paper, we present three peculiar broad absorption line quasars that were discovered during this spectroscopic survey, demonstrating the efficacy of this approach. PSS J0052+2405 is an iron low-ionization broad absorption line (LoBAL) quasar at a redshift z = 2.4512 \u00b1 0.0001 with very broad absorption from many species. PSS J0141+3334 is a reddened LoBAL quasar at z = 3.005 \u00b1 0.005 with no obvious emission lines. PSS J1537+1227 is an iron LoBAL at a redshift of z = 1.212 \u00b1 0.007 with strong narrow Mg II and Fe II emission. Follow-up high-resolution spectroscopy of these three quasars promises to improve our understanding of BAL quasars. The sensitivity of particular parameter spaces, in this case a two-color space, to the redshift of these three sources is dramatic, raising questions about traditional techniques of defining quasar populations for statistical analysis.", "doi": "10.1086/375763", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2003-07", "series_number": "1", "volume": "126", "issue": "1", "pages": "53-62" }, { "id": "authors:ffye2-yck59", "collection": "authors", "collection_id": "ffye2-yck59", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190924-112423363", "type": "article", "title": "The Northern Sky Optical Cluster Survey. II. An Objective Cluster Catalog for 5800 Square Degrees", "author": [ { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Lopes", "given_name": "P. A. A.", "clpid": "Lopes-P-A-A" }, { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Brunner", "given_name": "R. J.", "clpid": "Brunner-R-J" }, { "family_name": "Mahabal", "given_name": "A.", "orcid": "0000-0003-2242-0244", "clpid": "Mahabal-A-A" }, { "family_name": "Odewahn", "given_name": "S. C.", "clpid": "Odewahn-S-C" } ], "abstract": "We present a new, objectively defined catalog of candidate galaxy clusters based on the galaxy catalogs from the digitized Second Palomar Observatory Sky Survey. This cluster catalog, derived from the best calibrated plates in the high-latitude (|b| > 30\u00b0) northern Galactic cap region, covers 5800 deg^2 and contains 8155 candidate clusters. A simple adaptive kernel density mapping technique, combined with the SExtractor object detection algorithm, is used to detect galaxy overdensities, which we identify as clusters. Simulations of the background galaxy distribution and clusters of varying richnesses and redshifts allow us to optimize detection parameters and measure the completeness and contamination rates for our catalog. Cluster richnesses and photometric redshifts are measured, using integrated colors and magnitudes for each cluster. An extensive spectroscopic survey is used to confirm the photometric results. This catalog, with well-characterized sample properties, provides a sound basis for future studies of cluster physics and large-scale structure.", "doi": "10.1086/368240", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2003-04", "series_number": "4", "volume": "125", "issue": "4", "pages": "2064-2084" }, { "id": "authors:hy0h0-4pp86", "collection": "authors", "collection_id": "hy0h0-4pp86", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190806-150227509", "type": "monograph", "title": "The Digitized Second Palomar Observatory Sky Survey (DPOSS) II: Photometric Calibration", "author": [ { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Odewahn", "given_name": "S. C.", "clpid": "Odewahn-S-C" }, { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Mahabal", "given_name": "A.", "orcid": "0000-0003-2242-0244", "clpid": "Mahabal-A-A" }, { "family_name": "Brunner", "given_name": "R. J.", "clpid": "Brunner-R-J" }, { "family_name": "Lopes", "given_name": "P. A. A.", "clpid": "Lopes-P-A-A" } ], "abstract": "We present the photometric calibration technique for the Digitized Second Palomar Observatory Sky Survey (DPOSS), used to create seamless catalogs of calibrated objects over large sky areas. After applying a correction for telescope vignetting, the extensive plate overlap regions are used to transform sets of plates onto a common instrumental photometric system. Photometric transformations to the Gunn gri system for each plate, for stars and galaxies, are derived using these contiguous stitched areas and an extensive CCD imaging library obtained for this purpose. We discuss the resulting photometric accuracy, survey depth, and possible systematic errors.", "doi": "10.48550/arXiv.0210298", "publication_date": "2002-10-14" }, { "id": "authors:5qwam-mef51", "collection": "authors", "collection_id": "5qwam-mef51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180306-111017080", "type": "article", "title": "Luminosity function of clusters of galaxies", "author": [ { "family_name": "Paolillo", "given_name": "M.", "orcid": "0000-0003-4210-7693", "clpid": "Paolillo-M" }, { "family_name": "Andreon", "given_name": "S.", "clpid": "Andreon-S" }, { "family_name": "Longo", "given_name": "G.", "orcid": "0000-0002-9182-8414", "clpid": "Longo-G" }, { "family_name": "Puddu", "given_name": "E.", "clpid": "Puddu-E" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Scaramella", "given_name": "R.", "clpid": "Scaramella-R" }, { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" } ], "abstract": "The composite galaxy luminosity function (hereafter LF) of 39 Abell clusters of galaxies is derived by computing the statistical excess of galaxy counts in the cluster direction with respect to control fields. Due to the wide field coverage of the digitised POSS-II plates, we can measure field counts around each cluster in a fully homogeneous way. Furthermore, the availability of virtually unlimited sky coverage allows us to directly compute the LF errors without having to rely on the estimated variance of the background. The wide field coverage also allows us to derive the LF of the whole cluster, including galaxies located in the cluster outskirts. The global composite LF has a slope \u03b1 ~ -1.1 \u00b1 0.2 with minor variations from blue to red filters, and M* ~ -21.7, -22.2, -22.4 mag (H_0 = 50 km s^(-1) Mpc^(-1)) in g, r and i filters, respectively (errors are detailed in the text). These results are in quite good agreement with several previous determinations and in particular with the LF determined for the inner region of a largely overlapping set of clusters, but derived making use of a completely different method for background subtraction. The similarity of the two LFs suggests the existence of minor differences between the LF in the cluster outskirts and in the central region, or a negligible contribution of galaxies in the cluster outskirts to the global LF.", "doi": "10.1051/0004-6361:20000442", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2001-02-03", "series_number": "1", "volume": "367", "issue": "1", "pages": "59-71" }, { "id": "authors:7yn86-6h687", "collection": "authors", "collection_id": "7yn86-6h687", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190723-160211878", "type": "book_section", "title": "The Northern Sky Optical Cluster Survey", "book_title": "Mining the Sky", "author": [ { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "de Carvalho", "given_name": "Reinaldo R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Odewahn", "given_name": "Stephen C.", "clpid": "Odewahn-S-C" }, { "family_name": "Djorgovski", "given_name": "S. George", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Brunner", "given_name": "Robert J.", "clpid": "Brunner-R-J" }, { "family_name": "Margoniner", "given_name": "Vera E.", "clpid": "Margoniner-V-E" } ], "contributor": [ { "family_name": "Banday", "given_name": "Anthony J.", "clpid": "Banday-A-J" }, { "family_name": "Zaroubi", "given_name": "Saleem", "clpid": "Zaroubi-S" }, { "family_name": "Bartelmann", "given_name": "Matthias", "clpid": "Bartelmann-M" } ], "abstract": "The Northern Sky Optical Cluster Survey aims to create an objective catalog of galaxy clusters over the entire high-galactic-latitude Northern sky. We use the catalogs generated from the Digitized Second Palomar Sky Survey (DPOSS, Djorgovski et al. 1999) as the basis for this survey. We apply a color criterion to select against field galaxies, and use a simple adaptive kernel technique to create galaxy density maps, combined with the bootstrap technique to make significance maps, from which density peaks are selected. We find a mean surface density of \u223c1.5 clusters per square degree, consistent with the detection of richness class 0 and higher clusters to z\u223c0.3. In addition, we demonstrate an effective photometric redshift estimator for our clusters.", "doi": "10.1007/10849171_12", "isbn": "978-3-540-42468-0", "publisher": "Springer", "place_of_publication": "Berlin", "publication_date": "2001", "pages": "160-167" }, { "id": "authors:0cbxq-s8r44", "collection": "authors", "collection_id": "0cbxq-s8r44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190723-160758075", "type": "book_section", "title": "Exploration of Large Digital Sky Surveys", "book_title": "Mining the Sky", "author": [ { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Brunner", "given_name": "R. J.", "clpid": "Brunner-R-J" }, { "family_name": "Mahabal", "given_name": "A. A.", "orcid": "0000-0003-2242-0244", "clpid": "Mahabal-A-A" }, { "family_name": "Odewahn", "given_name": "S. C.", "clpid": "Odewahn-S-C" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Stolorz", "given_name": "P.", "clpid": "Stolorz-P" }, { "family_name": "Granat", "given_name": "R.", "clpid": "Granat-R" }, { "family_name": "Curkendall", "given_name": "D.", "clpid": "Curkendall-D-W" }, { "family_name": "Jacob", "given_name": "J.", "clpid": "Jacob-J" }, { "family_name": "Castro", "given_name": "S.", "clpid": "Castro-S" } ], "contributor": [ { "family_name": "Banday", "given_name": "Anthony J.", "clpid": "Banday-A-J" }, { "family_name": "Zaroubi", "given_name": "Saleem", "clpid": "Zaroubi-S" }, { "family_name": "Bartelmann", "given_name": "Matthias", "clpid": "Bartelmann-M" } ], "abstract": "We review some of the scientific opportunities and technical challenges posed by the exploration of the large digital sky surveys, in the context of a Virtual Observatory (VO). The VO paradigm will profoundly change the way observational astronomy is done. Clustering analysis techniques can be used to discover samples of rare, unusual, or even previously unknown types of astronomical objects and phenomena. Exploration of the previously poorly probed portions of the observable parameter space are especially promising. We illustrate some of the possible types of studies with examples drawn from DPOSS; much more complex and interesting applications are forthcoming. Development of the new tools needed for an efficient exploration of these vast data sets requires a synergy between astronomy and information sciences, with great potential returns for both fields.", "doi": "10.1007/10849171_37", "isbn": "978-3-540-42468-0", "publisher": "Springer", "place_of_publication": "Berlin", "publication_date": "2001", "pages": "305-322" }, { "id": "authors:qvtgm-1yn04", "collection": "authors", "collection_id": "qvtgm-1yn04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190723-155408196", "type": "book_section", "title": "Automated Search of LSB Galaxies in DPOSS (CRoNaRio Project): Method and First Results from Follow-Ups", "book_title": "Mining the Sky", "author": [ { "family_name": "Testa", "given_name": "Vincenzo", "clpid": "Testa-V" }, { "family_name": "Sabatini", "given_name": "Sabina", "clpid": "Sabatini-S" }, { "family_name": "Scaramella", "given_name": "Roberto", "clpid": "Scaramella-R" }, { "family_name": "Longo", "given_name": "Giuseppe", "orcid": "0000-0002-9182-8414", "clpid": "Longo-G" }, { "family_name": "Djorgovski", "given_name": "S. George", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Gal", "given_name": "Roy R.", "clpid": "Gal-R-R" }, { "family_name": "Brunner", "given_name": "Robert J.", "clpid": "Brunner-R-J" }, { "family_name": "de Carvalho", "given_name": "Reinaldo R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" } ], "contributor": [ { "family_name": "Banday", "given_name": "Anthony J.", "clpid": "Banday-A-J" }, { "family_name": "Zaroubi", "given_name": "Saleem", "clpid": "Zaroubi-S" }, { "family_name": "Bartelmann", "given_name": "Matthias", "clpid": "Bartelmann-M" } ], "abstract": "We developed an algorithm to search automatically for LSB galaxies in the DPOSS plate scans. The algorithm consists of three different steps in which: i) the original image is processed with a standard image analysis package (e.g. SExtractor) and normal high surface brightness objects are removed; ii) a series of filters with an exponential compensated profile are applied at different scales; iii) significance maps are pruned by selecting, for each detection, the characteristic scale and significance; iv) candidates are then trimmed by measuring them on the original image with a fit with an exponential profile. Multicolor optical follow-up with CCD has begun on some of the best candidates.", "doi": "10.1007/10849171_72", "isbn": "978-3-540-42468-0", "publisher": "Springer", "place_of_publication": "Berlin", "publication_date": "2001", "pages": "557-563" }, { "id": "authors:kffqy-v5338", "collection": "authors", "collection_id": "kffqy-v5338", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170223-070422097", "type": "article", "title": "The Host Galaxy of GRB 990123", "author": [ { "family_name": "Bloom", "given_name": "J. S.", "orcid": "0000-0002-7777-216X", "clpid": "Bloom-J-S" }, { "family_name": "Odewahn", "given_name": "S. C.", "clpid": "Odewahn-S-C" }, { "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": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Koresko", "given_name": "C.", "clpid": "Koresko-C-D" }, { "family_name": "Neugebauer", "given_name": "G.", "clpid": "Neugebauer-G" }, { "family_name": "Armus", "given_name": "L.", "orcid": "0000-0003-3498-2973", "clpid": "Armus-L" }, { "family_name": "Frail", "given_name": "D. A.", "clpid": "Frail-D-A" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Sari", "given_name": "R.", "orcid": "0000-0002-1084-3656", "clpid": "Sari-R" }, { "family_name": "Squires", "given_name": "G.", "orcid": "0000-0002-1977-5717", "clpid": "Squires-G-K" }, { "family_name": "Illingworth", "given_name": "G.", "orcid": "0000-0002-8096-2837", "clpid": "Illingworth-G-D" }, { "family_name": "Kelson", "given_name": "D.", "clpid": "Kelson-D-D" }, { "family_name": "Chaffee", "given_name": "F. H.", "clpid": "Chaffee-F-H-Jr" }, { "family_name": "Goodrich", "given_name": "R.", "clpid": "Goodrich-R-W" }, { "family_name": "Feroci", "given_name": "M.", "clpid": "Feroci-M" }, { "family_name": "Costa", "given_name": "E.", "clpid": "Costa-E" }, { "family_name": "Piro", "given_name": "L.", "clpid": "Piro-L" }, { "family_name": "Frontera", "given_name": "F.", "clpid": "Frontera-F" }, { "family_name": "Mao", "given_name": "S.", "orcid": "0000-0001-8317-2788", "clpid": "Mao-Shude" }, { "family_name": "Akerlof", "given_name": "C.", "clpid": "Akerlof-C-W" }, { "family_name": "McKay", "given_name": "T. A.", "clpid": "McKay-T-A" } ], "abstract": "We present deep images of the field of GRB 990123 obtained in a broadband UV/visible bandpass with the Hubble Space Telescope (HST) and deep near-infrared images obtained with the Keck I 10 m telescope. The HST image reveals that the optical transient (OT) is offset by 0farcs67 (5.8 kpc in projection) from an extended, apparently interacting galaxy. This galaxy, which we conclude is the host galaxy of GRB 990123, is the most likely source of the absorption lines of metals at a redshift of z=1.6 seen in the spectrum of the OT. With magnitudes of Gunn-r = 24.5 \u00b1 0.2 and K = 22.1\u00b10.3 mag, this corresponds to an L ~ 0.5L$\\mathstrut{_{*}}$ galaxy, assuming that it is located at z = 1.6. The estimated unobscured star formation rate is \u22484 M_\u2609 yr^(\u22121), which is typical for normal galaxies at comparable redshifts. There is no evidence for strong gravitational lensing magnification of this burst, and some alternative explanation for its remarkable energetics (such as beaming) may therefore be required. The observed offset of the OT from the nominal host center, the absence of broad absorption lines in the afterglow spectrum, and the relatively blue continuum of the host do not support the notion that gamma-ray bursts (GRBs) originate from active galactic nuclei or massive black holes. Rather, the data are consistent with models of GRBs that involve the death and/or merger of massive stars. Indeed, the HST image suggests an intimate connection between GRB 990123 and a star-forming region.", "doi": "10.1086/312059", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "1999-06-10", "series_number": "1", "volume": "518", "issue": "1", "pages": "L1-L4" }, { "id": "authors:a8mr1-26v46", "collection": "authors", "collection_id": "a8mr1-26v46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190723-161537020", "type": "book_section", "title": "Cataloging of the Digitized Poss-II: Initial Scientific Results", "book_title": "New Horizons from Multi-Wavelength Sky Surveys", "author": [ { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Pahre", "given_name": "M. A.", "clpid": "Pahre-M-A" }, { "family_name": "Scaramella", "given_name": "R.", "clpid": "Scaramella-R" }, { "family_name": "Longo", "given_name": "G.", "orcid": "0000-0002-9182-8414", "clpid": "Longo-G" } ], "contributor": [ { "family_name": "McLean", "given_name": "Brian J.", "clpid": "McLean-B-J" } ], "abstract": "The Second Palomar Sky Survey (POSS-II) is now nearing completion. It will cover the entire northern sky with 894 fields (6.5\u00b0 square) at 5\u00b0 spacings, with no gaps in the coverage. Plates are taken in three bands: IIIa-J + GG395, \u03bb_(eff) \u223c 480 nm; IIIa-F + RG610, \u03bb_(eff) \u223c 650 nm; and IV-N + RG9, \u03bb_(eff) \u223c 850 nm. Typical limiting magnitudes reached are B_J \u223c 22.5, R_F \u223c 20.8, and I_N \u223c 19.5, i.e., \u223c 1m \u22121.5m deeper than the POSS-I. The image quality is improved relative to the POSS-I, and is comparable to the southern photographic sky surveys. For more details, see Reid et al. (1987), and Reid & Djorgovski (1993).", "doi": "10.48550/arXiv.9612108", "isbn": "9780792348023", "publisher": "Kluwer", "place_of_publication": "Dordrecht", "publication_date": "1998", "pages": "424-430" }, { "id": "authors:wsbxg-smv82", "collection": "authors", "collection_id": "wsbxg-smv82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180711-101525969", "type": "book_section", "title": "Data mining a large digital sky survey: from the challenges to the scientific results", "book_title": "Applications of Digital Image Processing XX", "author": [ { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Odewahn", "given_name": "S. C.", "clpid": "Odewahn-S-C" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Roden", "given_name": "J.", "clpid": "Roden-J-C" }, { "family_name": "Stolorz", "given_name": "P.", "clpid": "Stolorz-P" }, { "family_name": "Gray", "given_name": "A.", "clpid": "Gray-A" } ], "contributor": [ { "family_name": "Tescher", "given_name": "Andrew G.", "clpid": "Tescher-A-G" } ], "abstract": "The analysis and an efficient scientific exploration of the digital Palomar observatory sky survey represents a major technical challenge. The input data set consists of 3 Terabytes of pixel information, and contains a few billion sources. We describe some of the specific scientific problems posed by the data, including searches for distant quasars and clusters of galaxies, and the data-mining techniques we are exploring in addressing them Machine- assisted discovery methods may become essential for the analysis of such multi-Terabyte data sets. New and future approaches involve unsupervised classification and clustering analysis in the Giga-object data space, including various Bayesian techniques. In addition to the searches for known types of objects in this database, these techniques may also offer the possibility of discovering previously unknown, rare types of astronomical objects.", "doi": "10.1117/12.292750", "isbn": "9780819425867", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "place_of_publication": "Bellingham, WA", "publication_date": "1997-10-30", "pages": "98-109" }, { "id": "authors:eyrmm-gsx68", "collection": "authors", "collection_id": "eyrmm-gsx68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150609-120007821", "type": "article", "title": "The optical counterpart to the \u03b3-ray burst GRB970508", "author": [ { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Metzger", "given_name": "M. R.", "clpid": "Metzger-M-R" }, { "family_name": "Kulkarni", "given_name": "S. R.", "orcid": "0000-0001-5390-8563", "clpid": "Kulkarni-S-R" }, { "family_name": "Odewahn", "given_name": "S. C.", "clpid": "Odewahn-S-C" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Pahre", "given_name": "M. A.", "clpid": "Pahre-M-A" }, { "family_name": "Frail", "given_name": "D. A.", "clpid": "Frail-D-A" }, { "family_name": "Feroci", "given_name": "M.", "clpid": "Feroci-M" }, { "family_name": "Costa", "given_name": "E.", "clpid": "Costa-E" }, { "family_name": "Palazzi", "given_name": "E.", "clpid": "Palazzi-E" } ], "abstract": "Understanding the nature of the gamma-ray burst phenomenon is one of the outstanding problems of modern astrophysics. The identification of counterparts at optical wavelengths is considered a crucial factor for determining the origin of these events. Here we report the detection and temporal properties of a variable optical source, which has been identified as the counterpart of the X-ray transient associated with the \u03b3-ray burst GRB970508 (ref. 3). The initial optical images were obtained only 5.8 hours after the initial gamma-ray burst, after which the optical source was observed to brighten over the next two days before declining in luminosity with a t-1 power law. The decline in brightness follows a form predicted by many relativistic fireball models for \u03b3-ray bursts, although the initial rise does not appear to be compatible with the simplest of these models. The observed fluence of the source at visible wavelengths over the period spanned by our observations is \u22654.6 times 10^(-8) erg cm^(-2), about 3% of the fluence of the gamma-ray burst itself.", "doi": "10.1038/43126", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1997-06-26", "series_number": "6636", "volume": "387", "issue": "6636", "pages": "876-878" }, { "id": "authors:2afps-55965", "collection": "authors", "collection_id": "2afps-55965", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190603-153225522", "type": "article", "title": "Dynamical Correlations for Globular Clusters in M31", "author": [ { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "McCarthy", "given_name": "J. K.", "clpid": "McCarthy-J-K" }, { "family_name": "Cohen", "given_name": "J. G.", "orcid": "0000-0002-8039-4673", "clpid": "Cohen-J-G" }, { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Meylan", "given_name": "G.", "clpid": "Meylan-G" }, { "family_name": "Bendinelli", "given_name": "O.", "clpid": "Bendinelli-O" }, { "family_name": "Parmeggiani", "given_name": "G.", "clpid": "Parmeggiani-G" } ], "abstract": "We present internal velocity dispersion measurements for a set of 21 globular clusters in the Andromeda galaxy (M31). We combine them with structural and photometric cluster parameters measured earlier with the Hubble Space Telescope and from the ground to explore correlations of cluster properties and to compare them with the equivalent correlations for the Galactic globular clusters. We find that the M31 globulars follow the same correlations between velocity dispersion and luminosity, central, and average surface brightness, as do their Galactic counterparts. This suggests a common physical origin for these correlations. They may be produced by the same astrophysical conditions and processes operating at the epoch of globular cluster formation in both galaxies. The very existence of these excellent correlations, and their quantitative form as scaling laws, represent challenges and constraints for theories of globular cluster formation. Preliminary estimates of the cluster M/L ratios show correlations with the cluster metallicity, in the sense of more metal-rich clusters having lower M/L, particularly in the near-infrared. At a given metallicity, there is no detectable systematic difference between the M31 globulars and their Galactic counterparts, which suggests a great similarity of their stellar populations. The observed scatter around these trends is comparable to the expected errors, which implies a small intrinsic scatter and thus which leaves little room for possible variations in the cluster age or stellar IMF at a given metallicity.", "doi": "10.1086/310423", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "1997-01-01", "series_number": "1", "volume": "474", "issue": "1", "pages": "L19-L22" }, { "id": "authors:mar67-trq96", "collection": "authors", "collection_id": "mar67-trq96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190724-073811293", "type": "book_section", "title": "Towards an Objectively Defined Catalog of Galaxy Clusters from the Digitized POSS-II", "book_title": "Wide-Field Spectroscopy", "author": [ { "family_name": "de Carvalho", "given_name": "R. R.", "orcid": "0000-0002-1283-3363", "clpid": "de-Carvalho-R-R" }, { "family_name": "Djorgovski", "given_name": "S. G.", "orcid": "0000-0002-0603-3087", "clpid": "Djorgovski-S-G" }, { "family_name": "Pahre", "given_name": "M.", "clpid": "Pahre-M-A" }, { "family_name": "Gal", "given_name": "R. R.", "clpid": "Gal-R-R" }, { "family_name": "Gray", "given_name": "A.", "clpid": "Gray-A" }, { "family_name": "Roden", "given_name": "J.", "clpid": "Roden-J" } ], "contributor": [ { "family_name": "Kontizas", "given_name": "E.", "clpid": "Kontizas-E" }, { "family_name": "Kontizas", "given_name": "M.", "clpid": "Kontizas-M" }, { "family_name": "Morgan", "given_name": "D. H.", "clpid": "Morgan-D-H" }, { "family_name": "Vettolani", "given_name": "G. P.", "clpid": "Vettolani-G-P" } ], "abstract": "The subjective nature of the Abell catalog has been widely recognized as its major limitation. We report on the preliminary results of an effort to create an unbiased catalog of clusters of galaxies from the galaxy catalogs derived from the digitized POSS-II (DPOSS).", "doi": "10.1007/978-94-011-5722-3_51", "isbn": "978-94-010-6413-2", "publisher": "Springer", "place_of_publication": "Dordrecht", "publication_date": "1997", "pages": "285-286" } ]