[ { "id": "authors:5mn5c-p1c24", "collection": "authors", "collection_id": "5mn5c-p1c24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140912-084914153", "type": "article", "title": "The 6dF Galaxy Survey: Fundamental Plane data", "author": [ { "family_name": "Campbell", "given_name": "Lachlan A.", "clpid": "Campbell-L-A" }, { "family_name": "Lucey", "given_name": "John R.", "clpid": "Lucey-J-R" }, { "family_name": "Colless", "given_name": "Matthew", "orcid": "0000-0001-9552-8075", "clpid": "Colless-M" }, { "family_name": "Jones", "given_name": "D. Heath", "clpid": "Jones-D-H" }, { "family_name": "Springob", "given_name": "Christopher M.", "clpid": "Springob-C-M" }, { "family_name": "Magoulas", "given_name": "Christina", "clpid": "Magoulas-C" }, { "family_name": "Proctor", "given_name": "Robert N.", "clpid": "Proctor-R-N" }, { "family_name": "Mould", "given_name": "Jeremy R.", "orcid": "0000-0003-3820-1740", "clpid": "Mould-J-R" }, { "family_name": "Read", "given_name": "Mike A.", "clpid": "Read-M-A" }, { "family_name": "Brough", "given_name": "Sarah", "orcid": "0000-0002-9796-1363", "clpid": "Brough-S" }, { "family_name": "Jarrett", "given_name": "Tom", "clpid": "Jarrett-T" }, { "family_name": "Merson", "given_name": "Alex I.", "clpid": "Merson-A-I" }, { "family_name": "Lah", "given_name": "Philip", "clpid": "Lah-P" }, { "family_name": "Beutler", "given_name": "Florian", "clpid": "Beutler-F" }, { "family_name": "Cluver", "given_name": "Michelle E.", "orcid": "0000-0002-9871-6490", "clpid": "Cluver-M-E" }, { "family_name": "Parker", "given_name": "Quentin A.", "clpid": "Parker-Q-A" } ], "abstract": "We report the 6dFGS Fundamental Plane (6dFGSv) catalogue that is used to estimate distances and peculiar velocities for nearly 9000 early-type galaxies in the local (z < 0.055) universe. Velocity dispersions are derived by cross-correlation from 6dF V-band spectra with typical S/N of 12.9\u2009\u00c5^(\u22121) for a sample of 11 315 galaxies; the median velocity dispersion is 163\u2009km\u2009s^(\u22121) and the median measurement error is 12.9 per cent. The photometric Fundamental Plane (FP) parameters (effective radii and surface brightnesses) are determined from the JHK 2MASS images for 11 102 galaxies. Comparison of the independent J- and K-band measurements implies that the average uncertainty in X_(FP), the combined photometric parameter that enters the FP, is 0.013\u2009dex (3 per cent) for each band. Visual classification of morphologies was used to select a sample of nearly 9000 early-type galaxies that form 6dFGSv. This catalogue has been used to study the effects of stellar populations on galaxy scaling relations, to investigate the variation of the FP with environment and galaxy morphology, to explore trends in stellar populations through, along and across the FP, and to map and analyse the local peculiar velocity field.", "doi": "10.1093/mnras/stu1198", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2014-09-11", "series_number": "2", "volume": "443", "issue": "2", "pages": "1231-1251" }, { "id": "authors:hht71-vaw44", "collection": "authors", "collection_id": "hht71-vaw44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130118-133725427", "type": "article", "title": "The 6dF Galaxy Survey: the near-infrared Fundamental Plane of\n early-type galaxies", "author": [ { "family_name": "Magoulas", "given_name": "Christina", "clpid": "Magoulas-C" }, { "family_name": "Springob", "given_name": "Christopher M.", "clpid": "Springob-C-M" }, { "family_name": "Colless", "given_name": "Matthew", "orcid": "0000-0001-9552-8075", "clpid": "Colless-M" }, { "family_name": "Jones", "given_name": "D. Heath", "clpid": "Jones-D-H" }, { "family_name": "Campbell", "given_name": "Lachlan A.", "clpid": "Campbell-L-A" }, { "family_name": "Lucey", "given_name": "John R.", "clpid": "Lucey-J-R" }, { "family_name": "Mould", "given_name": "Jeremy", "orcid": "0000-0003-3820-1740", "clpid": "Mould-J-R" }, { "family_name": "Jarrett", "given_name": "Tom", "clpid": "Jarrett-T" }, { "family_name": "Merson", "given_name": "Alex", "clpid": "Merson-A" }, { "family_name": "Brough", "given_name": "Sarah", "orcid": "0000-0002-9796-1363", "clpid": "Brough-S" } ], "abstract": "We determine the near-infrared Fundamental Plane (FP) for \u223c10^4 early-type galaxies in the 6-degree Field Galaxy Survey (6dFGS). We fit the distribution of central velocity dispersion, near-infrared surface brightness and half-light radius with a 3D Gaussian model using a maximum-likelihood method. The model provides an excellent empirical fit to the observed FP distribution and the method proves robust and unbiased. Tests using simulations show that it gives superior results to regression techniques in the presence of significant and correlated uncertainties in all three parameters, censoring of the data by various selection effects and outliers in the data sample. For the 6dFGS J-band sample we find an FP with R_e \u221d \u03c3^(1.52\u00b10.03)_0 I_e^(\u22120.89\u00b10.01), similar to previous near-infrared determinations and consistent with the H- and K-band FPs once allowance is made for differences in mean colour. The overall scatter in R_e about the FP is \u03c3_r = 29 per cent, and is the quadrature sum of an 18 per cent scatter due to observational errors and a 23 per cent intrinsic scatter. Because of the Gaussian distribution of galaxies in FP space, \u03c3_r is not the distance error, which we find to be \u03c3_d = 23 per cent. Using group richness and local density as measures of environment, and morphologies based on visual classifications, we find that the FP slopes do not vary with environment or morphology. However, for fixed velocity dispersion and surface brightness, field galaxies are on average 5 per cent larger than galaxies in groups or higher density environments, and the bulges of early-type spirals are on average 10 per cent larger than ellipticals and lenticulars. The residuals about the FP show significant trends with environment, morphology and stellar population. The strongest trend is with age, and we speculate that age is the most important systematic source of offsets from the FP, and may drive the other trends through its correlations with environment, morphology and metallicity. These results will inform our use of the near-infrared FP in deriving relative distances and peculiar velocities for 6dFGS galaxies.", "doi": "10.1111/j.1365-2966.2012.21421.x", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2012-11", "series_number": "1", "volume": "427", "issue": "1", "pages": "245-273" }, { "id": "authors:85e6s-wx372", "collection": "authors", "collection_id": "85e6s-wx372", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101027-090634050", "type": "article", "title": "The Southern 2MASS Active Galactic Nuclei Survey: Spectroscopic Follow-up with Six Degree Field", "author": [ { "family_name": "Masci", "given_name": "Frank J.", "orcid": "0000-0002-8532-9395", "clpid": "Masci-F-J" }, { "family_name": "Cutri", "given_name": "Roc M.", "orcid": "0000-0002-0077-2305", "clpid": "Cutri-R-M" }, { "family_name": "Francis", "given_name": "Paul J.", "clpid": "Francis-P-J" }, { "family_name": "Nelson", "given_name": "Brant O.", "clpid": "Nelson-B-O" }, { "family_name": "Huchra", "given_name": "John P.", "clpid": "Huchra-J-P" }, { "family_name": "Jones", "given_name": "D. Heath", "clpid": "Jones-D-H" }, { "family_name": "Colless", "given_name": "Matthew", "orcid": "0000-0001-9552-8075", "clpid": "Colless-M" }, { "family_name": "Saunders", "given_name": "Will", "clpid": "Saunders-W" } ], "abstract": "The Two Micron All-Sky Survey (2MASS) has provided a uniform photometric catalog to search for previously unknown red active galactic nuclei (AGN) and Quasi-Stellar Objects (QSOs). We have extended the search to the southern equatorial sky by obtaining spectra for 1182 AGN candidates using the six degree field (6dF) multifibre spectrograph on the UK Schmidt Telescope. These were scheduled as auxiliary targets for the 6dF Galaxy Redshift Survey. The candidates were selected using a single color cut of J \u2013 K_s > 2 to K_s \u227e 15.5 and a galactic latitude of |b| > 30\u00b0. 432 spectra were of sufficient quality to enable a reliable classification. 116 sources (~27%) were securely classified as type I AGN, 20 as probable type I AGN, and 57 as probable type II AGN. Most of them span the redshift range 0.05 < z < 0.5 and only 8 (~6%) were previously identified as AGN or QSOs. Our selection leads to a significantly higher AGN identification rate amongst local galaxies (>20%) than in any previous (mostly blue-selected) galaxy survey. A small fraction of the type I AGN could have their optical colors reddened by optically thin dust with A_V < 2 mag relative to optically selected QSOs. A handful show evidence of excess far-infrared (IR) emission. The equivalent width (EW) and color distributions of the type I and II AGN are consistent with AGN unified models. In particular, the EW of the [OIII] emission line weakly correlates with optical\u2013near-IR color in each class of AGN, suggesting anisotropic obscuration of the AGN continuum. Overall, the optical properties of the 2MASS red AGN are not dramatically different from those of optically-selected QSOs. Our near-IR selection appears to detect the most near-IR luminous QSOs in the local universe to z \u2243 0.6 and provides incentive to extend the search to deeper near-IR surveys.", "doi": "10.1071/AS10001", "issn": "1323-3580", "publisher": "CSIRO Publishing", "publication": "Publications of the Astronomical Society of Australia", "publication_date": "2010", "series_number": "3", "volume": "27", "issue": "3", "pages": "302-320" }, { "id": "authors:q0jbp-fhd85", "collection": "authors", "collection_id": "q0jbp-fhd85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091102-131150092", "type": "article", "title": "The 6dF Galaxy Survey: final redshift release (DR3) and southern large-scale structures", "author": [ { "family_name": "Jones", "given_name": "D. Heath", "clpid": "Jones-D-H" }, { "family_name": "Read", "given_name": "Mike A.", "clpid": "Read-M-A" }, { "family_name": "Saunders", "given_name": "Will", "clpid": "Saunders-W" }, { "family_name": "Colless", "given_name": "Matthew", "orcid": "0000-0001-9552-8075", "clpid": "Colless-M" }, { "family_name": "Jarrett", "given_name": "Tom", "clpid": "Jarrett-T" }, { "family_name": "Parker", "given_name": "Quentin A.", "clpid": "Parker-Q-A" }, { "family_name": "Fairall", "given_name": "Anthony P.", "clpid": "Fairall-A-P" }, { "family_name": "Mauch", "given_name": "Thomas", "clpid": "Mauch-T" }, { "family_name": "Sadler", "given_name": "Elaine M.", "clpid": "Sadler-E-M" }, { "family_name": "Watson", "given_name": "Fred G.", "clpid": "Watson-F-G" }, { "family_name": "Burton", "given_name": "Donna", "clpid": "Burton-D" }, { "family_name": "Campbell", "given_name": "Lachlan A.", "clpid": "Campbell-L-A" }, { "family_name": "Cass", "given_name": "Paul", "clpid": "Cass-P" }, { "family_name": "Croom", "given_name": "Scott M.", "orcid": "0000-0003-2880-9197", "clpid": "Croom-S-M" }, { "family_name": "Dawe", "given_name": "John", "clpid": "Dawe-J" }, { "family_name": "Fiegert", "given_name": "Kristin", "clpid": "Fiegert-K" }, { "family_name": "Frankcombe", "given_name": "Leela", "clpid": "Frankcombe-L" }, { "family_name": "Hartley", "given_name": "Malcolm", "clpid": "Hartley-Malcolm" }, { "family_name": "Huchra", "given_name": "John", "clpid": "Huchra-J-P" }, { "family_name": "James", "given_name": "Dionne", "clpid": "James-D" }, { "family_name": "Kirby", "given_name": "Emma", "clpid": "Kirby-Emma" }, { "family_name": "Lahav", "given_name": "Ofer", "clpid": "Lahav-O" }, { "family_name": "Lucey", "given_name": "John", "clpid": "Lucey-J" }, { "family_name": "Mamon", "given_name": "Gary A.", "clpid": "Mamon-G-A" }, { "family_name": "Moore", "given_name": "Lesa", "clpid": "Moore-L" }, { "family_name": "Peterson", "given_name": "Bruce A.", "clpid": "Peterson-B-A" }, { "family_name": "Prior", "given_name": "Sayuri", "clpid": "Prior-S" }, { "family_name": "Proust", "given_name": "Dominique", "clpid": "Proust-D" }, { "family_name": "Russell", "given_name": "Ken", "clpid": "Russell-K" }, { "family_name": "Safouris", "given_name": "Vicky", "clpid": "Safouris-V" }, { "family_name": "Wakamatsu", "given_name": "Ken-ichi", "clpid": "Wakamatsu-K" }, { "family_name": "Westra", "given_name": "Eduard", "clpid": "Westra-E" }, { "family_name": "Williams", "given_name": "Mary", "clpid": "Williams-M" } ], "abstract": "We report the final redshift release of the 6dF Galaxy Survey (6dFGS), a combined redshift and peculiar velocity survey over the southern sky (|b| > 10\u00b0). Its 136 304 spectra have yielded 110 256 new extragalactic redshifts and a new catalogue of 125 071 galaxies making near-complete samples with (K, H, J, r_F, b_J) \u2264 (12.65, 12.95, 13.75, 15.60, 16.75). The median redshift of the survey is 0.053. Survey data, including images, spectra, photometry and redshifts, are available through an online data base. We describe changes to the information in the data base since earlier interim data releases. Future releases will include velocity dispersions, distances and peculiar velocities for the brightest early-type galaxies, comprising about 10 per cent of the sample. Here we provide redshift maps of the southern local Universe with z \u2264 0.1, showing nearby large-scale structures in hitherto unseen detail. A number of regions known previously to have a paucity of galaxies are confirmed as significantly underdense regions. The URL of the 6dFGS data base is http://www-wfau.roe.ac.uk/6dFGS.", "doi": "10.1111/j.1365-2966.2009.15338.x", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2009-10-21", "series_number": "2", "volume": "399", "issue": "2", "pages": "683-698" }, { "id": "authors:9sg03-bwd71", "collection": "authors", "collection_id": "9sg03-bwd71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:ERDmnras06b", "type": "article", "title": "Reconstructed density and velocity fields from the 2MASS Redshift Survey", "author": [ { "family_name": "Erdo\u011fdu", "given_name": "Pirin", "clpid": "Erdo\u011fdu-P" }, { "family_name": "Lahav", "given_name": "Ofer", "clpid": "Lahav-O" }, { "family_name": "Huchra", "given_name": "John P.", "clpid": "Huchra-J-P" }, { "family_name": "Colless", "given_name": "Matthew", "orcid": "0000-0001-9552-8075", "clpid": "Colless-M" }, { "family_name": "Cutri", "given_name": "Roc M.", "orcid": "0000-0002-0077-2305", "clpid": "Cutri-R-M" }, { "family_name": "Falco", "given_name": "Emilio", "clpid": "Falco-E-E" }, { "family_name": "George", "given_name": "Teddy", "clpid": "George-T" }, { "family_name": "Jarrett", "given_name": "Thomas", "orcid": "0000-0002-4939-734X", "clpid": "Jarrett-T-H" }, { "family_name": "Jones", "given_name": "D. Heath", "clpid": "Jones-D-H" }, { "family_name": "Macri", "given_name": "Lucas M.", "clpid": "Macri-L-M" }, { "family_name": "Mader", "given_name": "Jeff", "clpid": "Mader-J" }, { "family_name": "Martimbeau", "given_name": "Nathalie", "clpid": "Martimbeau-N" }, { "family_name": "Pahre", "given_name": "Michael A.", "clpid": "Pahre-M-A" }, { "family_name": "Parker", "given_name": "Quentin A.", "clpid": "Parker-Q-A" }, { "family_name": "Rassat", "given_name": "Ana\u00efs", "clpid": "Rassat-A" }, { "family_name": "Saunders", "given_name": "Will", "clpid": "Saunders-W" } ], "abstract": "We present the reconstructed real-space density and the predicted velocity fields from the Two-Micron All-Sky Redshift Survey (2MRS). The 2MRS is the densest all-sky redshift survey to date and includes about 23 200 galaxies with extinction-corrected magnitudes brighter than Ks= 11.25 . Our method is based on the expansion of these fields in Fourier\u2013Bessel functions. Within this framework, the linear redshift distortions only affect the density field in the radial direction and can easily be deconvolved using a distortion matrix. Moreover, in this coordinate system, the velocity field is related to the density field by a simple linear transformation. The shot noise errors in the reconstructions are suppressed by means of a Wiener filter which yields a minimum variance estimate of the density and velocity fields. Using the reconstructed real-space density fields, we identify all major superclusters and voids. At 50 h^\u22121 Mpc , our reconstructed velocity field indicates a backside infall to the Great Attractor region of vinfall= (491 \u00b1 200) (\u03b2/0.5) km s^\u22121 in the Local Group frame and vinfall= (64 \u00b1 205) (\u03b2/0.5) km s^\u22121 in the cosmic microwave background (CMB) frame and \u03b2 is the redshift distortion parameter. The direction of the reconstructed dipole agrees well with the dipole derived by Erdo\u011fdu et al. The misalignment between the reconstructed 2MRS and the CMB dipoles drops to 13\u00b0 at around 5000 km s^\u22121 but then increases at larger distances.", "doi": "10.1111/j.1365-2966.2006.11049.x", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2006-11-21", "series_number": "1", "volume": "373", "issue": "1", "pages": "45-64" }, { "id": "authors:v34kz-t7559", "collection": "authors", "collection_id": "v34kz-t7559", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:ERDmnras06a", "type": "article", "title": "The dipole anisotropy of the 2 Micron All-Sky Redshift Survey", "author": [ { "family_name": "Erdo\u011fdu", "given_name": "Pirin", "clpid": "Erdo\u011fdu-P" }, { "family_name": "Huchra", "given_name": "J. P.", "clpid": "Huchra-J-P" }, { "family_name": "Lahav", "given_name": "O.", "clpid": "Lahav-O" }, { "family_name": "Colless", "given_name": "M.", "orcid": "0000-0001-9552-8075", "clpid": "Colless-M" }, { "family_name": "Cutri", "given_name": "R. M.", "orcid": "0000-0002-0077-2305", "clpid": "Cutri-R-M" }, { "family_name": "Falco", "given_name": "E.", "clpid": "Falco-E-E" }, { "family_name": "George", "given_name": "T.", "clpid": "George-T" }, { "family_name": "Jarrett", "given_name": "T.", "orcid": "0000-0002-4939-734X", "clpid": "Jarrett-T-H" }, { "family_name": "Jones", "given_name": "D. H.", "clpid": "Jones-D-H" }, { "family_name": "Kochanek", "given_name": "C. S.", "orcid": "0000-0001-6017-2961", "clpid": "Kochanek-C-S" }, { "family_name": "Macri", "given_name": "L.", "clpid": "Macri-L-M" }, { "family_name": "Mader", "given_name": "J.", "clpid": "Mader-J-A" }, { "family_name": "Martimbeau", "given_name": "N.", "clpid": "Martimbeau-N" }, { "family_name": "Pahre", "given_name": "M.", "clpid": "Pahre-M-A" }, { "family_name": "Parker", "given_name": "Q.", "clpid": "Parker-Q-A" }, { "family_name": "Rassat", "given_name": "A.", "clpid": "Rassat-A" }, { "family_name": "Saunders", "given_name": "W. H.", "clpid": "Saunders-W-H" } ], "abstract": "We estimate the acceleration on the Local Group (LG) from the 2 Micron All-Sky Redshift Survey (2MRS). The sample used includes about 23 200 galaxies with extinction-corrected magnitudes brighter than Ks= 11.25 and it allows us to calculate the flux-weighted dipole. The near-infrared flux-weighted dipoles are very robust because they closely approximate a mass-weighted dipole, bypassing the effects of redshift distortions and require no preferred reference frame. This is combined with the redshift information to determine the change in dipole with distance. The misalignment angle between the LG and the cosmic microwave background (CMB) dipole drops to 12\u00b0\u00b1 7\u00b0 at around 50 h^\u22121 Mpc, but then increases at larger distances, reaching 21\u00b0\u00b1 8\u00b0 at around 130 h^\u22121 Mpc . Exclusion of the galaxies Maffei 1, Maffei 2, Dwingeloo 1, IC342 and M87 brings the resultant flux dipole to 14\u00b0\u00b1 7\u00b0 away from the CMB velocity dipole. In both cases, the dipole seemingly converges by 60 h^\u22121 Mpc. Assuming convergence, the comparison of the 2MRS flux dipole and the CMB dipole provides a value for the combination of the mass density and luminosity bias parameters \u03a90.6m/bL= 0.40 \u00b1 0.09.", "doi": "10.1111/j.1365-2966.2006.10243.x", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2006-06-01", "series_number": "4", "volume": "368", "issue": "4", "pages": "1515-1526" }, { "id": "authors:q89mc-rz721", "collection": "authors", "collection_id": "q89mc-rz721", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150114-095601114", "type": "article", "title": "Visible and Far-Ultraviolet WFPC2 Imaging of the Nucleus of the Galaxy NGC 205", "author": [ { "family_name": "Jones", "given_name": "D. Heath", "clpid": "Jones-D-H" }, { "family_name": "Mould", "given_name": "Jeremy R.", "orcid": "0000-0003-3820-1740", "clpid": "Mould-J-R" }, { "family_name": "Watson", "given_name": "Alan M.", "clpid": "Watson-A-M" }, { "family_name": "Grillmair", "given_name": "Carl", "orcid": "0000-0003-4072-169X", "clpid": "Grillmair-C-J" }, { "family_name": "Gallagher", "given_name": "John S., III", "orcid": "0000-0001-8608-0408", "clpid": "Gallagher-J-S-III" }, { "family_name": "Ballester", "given_name": "Gilda E.", "clpid": "Ballester-G-E" }, { "family_name": "Burrows", "given_name": "Christopher J.", "clpid": "Burrows-C-J" }, { "family_name": "Casertano", "given_name": "Stefano", "clpid": "Casertano-S" }, { "family_name": "Clarke", "given_name": "John T.", "clpid": "Clarke-J-T" }, { "family_name": "Crisp", "given_name": "David", "orcid": "0000-0002-4573-9998", "clpid": "Crisp-D" }, { "family_name": "Griffiths", "given_name": "Richard E.", "clpid": "Griffiths-R" }, { "family_name": "Hester", "given_name": "J. Jeff", "clpid": "Hester-J-J" }, { "family_name": "Hoessel", "given_name": "John G.", "clpid": "Hoessel-J-G" }, { "family_name": "Holtzman", "given_name": "Jon A.", "clpid": "Holtzman-J-A" }, { "family_name": "Scowen", "given_name": "Paul A.", "clpid": "Scowen-P-A" }, { "family_name": "Stapelfeldt", "given_name": "Karl R.", "orcid": "0000-0002-2805-7338", "clpid": "Stapelfeldt-K-R" }, { "family_name": "Trauger", "given_name": "John T.", "clpid": "Trauger-J-T" }, { "family_name": "Westphal", "given_name": "James A.", "clpid": "Westphal-J-A" } ], "abstract": "We have imaged the nucleus of NGC 205 through the F555W and F160BW filters of WFPC2 on the high-resolution planetary camera (PC). The nucleus consists of a resolved cluster of stars extending 7\" X 6\".\nThe projected radial distribution of surface brightness can be fitted by a Hubble law with a small core of FWHM 214 x 190 mas (0.74 x 0.66 pc). We find that the nucleus of NGC 205 shares a number of characteristics with globular clusters. Absolute photometry is also presented in a half-arcsec aperture and is found to verify the amount of UV upturn observed in the spectral energy distribution of the nucleus by others (e.g., Bertola et al. 1995).\nOf the hypotheses available to explain the origin of the nucleus, the observations are most consistent with its being an intermediate age cluster. The most likely scenarios are that it is a either a star cluster whose orbit has decayed-therefore drawing it to rest at the galaxy center-or a cluster that has formed as the repository of the gas from generations of star formation.\nTogether with the ground-based measurement of a low-velocity dispersion, the small core radius implies a 107 yr relaxation time, suggesting the cluster core may have collapsed. An upper limit of 9 x 10^4 M_\u2609 can be put on the mass of any central black hole.", "doi": "10.1086/177547", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "1996-08-01", "series_number": "2", "volume": "466", "issue": "2", "pages": "742-749" } ]