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The Space Density of Extended Ultraviolet (XUV) Disks in the Local Universe and Implications for Gas Accretion onto Galaxies

Lemonias, Jenna J. and Schiminovich, David and Thilker, David and Wyder, Ted K. and Martin, D. Christopher and Seibert, Mark and Treyer, Marie A. and Bianchi, Luciana and Heckman, Timothy M. and Madore, Barry F. and Rich, R. Michael (2011) The Space Density of Extended Ultraviolet (XUV) Disks in the Local Universe and Implications for Gas Accretion onto Galaxies. Astrophysical Journal, 733 (2). Art. No. 74. ISSN 0004-637X.

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We present results of the first unbiased search for extended ultraviolet (XUV)-disk galaxies undertaken to determine the space density of such galaxies. Our sample contains 561 local (0.001 < z < 0.05) galaxies that lie in the intersection of available Galaxy Evolution Explorer (GALEX) deep imaging (exposure time >1.5 × 10^4 s) and Sloan Digital Sky Survey DR7 footprints. We explore modifications to the standard classification scheme for our sample that includes both disk- and bulge-dominated galaxies. Visual classification of each galaxy in the sample reveals an XUV-disk frequency of up to 20% for the most nearby portion of our sample. On average over the entire sample (out to z = 0.05) the frequency ranges from a hard limit of 4%-14%. The GALEX imaging allows us to detect XUV disks beyond 100 Mpc. The XUV regions around XUV-disk galaxies are consistently bluer than the main bodies. We find a surprisingly high frequency of XUV emission around luminous red (NUV-r > 5) and green valley (3 < NUV-r < 5) galaxies. The XUV-disk space density in the local universe is >(1.5-4.2) × 10^(–3) Mpc^(–3). Using the XUV emission as an indicator of recent gas accretion, we estimate that the cold gas accretion rate onto these galaxies is >(1.7-4.6) × 10^(–3) M_⊙ Mpc^(–3) yr^(–1). The number of XUV disks in the green valley and the estimated accretion rate onto such galaxies points to the intriguing possibility that 7%-18% of galaxies in this population are transitioning away from the red sequence.

Item Type:Article
Related URLs:
URLURL TypeDescription
Thilker, David0000-0002-8528-7340
Martin, D. Christopher0000-0002-8650-1644
Seibert, Mark0000-0002-1143-5515
Bianchi, Luciana0000-0001-7746-5461
Madore, Barry F.0000-0002-1576-1676
Rich, R. Michael0000-0003-0427-8387
Additional Information:© 2011 The American Astronomical Society. Received 2010 September 28; accepted 2011 March 10; published 2011 May 6. We thank the anonymous referee for valuable comments that substantially improved the quality of this paper. The Galaxy Evolution Explorer (GALEX) is a NASA Small Explorer, launched in 2003 April. We gratefully acknowledge NASA’s support for construction, operation, and science analysis for the GALEX mission, developed in cooperation with the Centre National d’Études Spatiales (CNES) of France and the Korean Ministry of Science and Technology. This work has made extensive use of the MPA/JHU and the NYU SDSS value-added catalogs. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSSWeb site is The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions. The Participating Institutions are the American Museum of Natural History, Astrophysical Institute Potsdam, University of Basel, University of Cambridge, Case Western Reserve University, University of Chicago, Drexel University, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, the Joint Institute for Nuclear Astrophysics, the Kavli Institute for Particle Astrophysics and Cosmology, the Korean Scientist Group, the Chinese Academy of Sciences (LAMOST), Los Alamos National Laboratory, the Max-Planck- Institute for Astronomy (MPIA), the Max-Planck-Institute for Astrophysics (MPA), New Mexico State University, Ohio State University, University of Pittsburgh, University of Portsmouth, Princeton University, the United States Naval Observatory, and the University of Washington. Facilities: GALEX, Sloan
Group:Space Astrophysics Laboratory
Funding AgencyGrant Number
Alfred P. Sloan FoundationUNSPECIFIED
Participating InstitutionsUNSPECIFIED
Department of Energy (DOE)UNSPECIFIED
Japanese MonbukagakushoUNSPECIFIED
Max Planck SocietyUNSPECIFIED
Higher Education Funding Council for EnglandUNSPECIFIED
American Museum of Natural HistoryUNSPECIFIED
Astrophysical Institute PotsdamUNSPECIFIED
University of BaselUNSPECIFIED
University of CambridgeUNSPECIFIED
Case Western Reserve UniversityUNSPECIFIED
University of ChicagoUNSPECIFIED
Drexel UniversityUNSPECIFIED
Institute for Advanced StudyUNSPECIFIED
Japan Participation GroupUNSPECIFIED
Johns Hopkins UniversityUNSPECIFIED
Joint Institute for Nuclear AstrophysicsUNSPECIFIED
Kavli Institute for Particle Astrophysics and CosmologyUNSPECIFIED
Korean Scientist GroupUNSPECIFIED
Chinese Academy of SciencesUNSPECIFIED
Los Alamos National LaboratoryUNSPECIFIED
Max-Planck-Institute for Astrophysics (MPA)UNSPECIFIED
New Mexico State UniversityUNSPECIFIED
Ohio State UniversityUNSPECIFIED
University of PittsburghUNSPECIFIED
University of PortsmouthUNSPECIFIED
Princeton UniversityUNSPECIFIED
United States Naval ObservatoryUNSPECIFIED
University of WashingtonUNSPECIFIED
Subject Keywords:galaxies: evolution; galaxies: formation; galaxies: structure; surveys; ultraviolet: galaxies
Issue or Number:2
Classification Code:PACS: 98.62.Ai; 98.62.Hr; 98.62.Mw; 98.62.Js; 98.62.Py; 95.85.Mt
Record Number:CaltechAUTHORS:20110607-083832342
Persistent URL:
Official Citation:The Space Density of Extended Ultraviolet (XUV) Disks in the Local Universe and Implications for Gas Accretion onto Galaxies Jenna J. Lemonias, David Schiminovich, David Thilker, Ted K. Wyder, D. Christopher Martin, Mark Seibert, Marie A. Treyer, Luciana Bianchi, Timothy M. Heckman, Barry F. Madore and R. Michael Rich doi: 10.1088/0004-637X/733/2/74
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:23922
Deposited By: Ruth Sustaita
Deposited On:07 Jun 2011 16:15
Last Modified:09 Mar 2020 23:46

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