To be published in 2006 ApJS.
astro-ph/0606440

For a PDF version of the article, click here.

THE GALEX ULTRAVIOLET ATLAS OF NEARBY GALAXIES

Armando Gil de Paz 1, Samuel Boissier 1, Barry F. Madore 1,2, Mark Seibert 3, Young H. Joe 1,4, Alessandro Boselli 5, Ted K. Wyder 3, David Thilker 6, Luciana Bianchi 6, Soo-Chang Rey 3, R. Michael Rich 7, Tom A. Barlow 3, Tim Conrow 3, Karl Forster 3, Peter G. Friedman 3, D. Christopher Martin 3, Patrick Morrissey 3, Susan G. Neff 8, David Schiminovich 3, Todd Small 3, José Donas 5, Timothy M. Heckman 9, Young-Wook Lee 4, Bruno Milliard 5, Alex S. Szalay 9, Sukyoung Yi 4

1 The Observatories, Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101; agpaz, boissier, young@ociw.edu; AGdP's current address: Departamento de Astrofísica, Universidad Complutense de Madrid, Madrid 28040, Spain; SB's current address: Laboratoire d'Astrophysique de Marseille, BP 8, Traverse du Siphon, 13376 Marseille Cedex 12, France.
2 NASA/IPAC Extragalactic Database, California Institute of Technology, MS 100-22, Pasadena, CA 91125; barry@ipac.caltech.edu
3 California Institute of Technology, MC 405-47, 1200 East California Boulevard, Pasadena, CA 91125; mseibert, wyder, screy, tab, tim, krl, friedman, cmartin, patrick, ds, tas@srl.caltech.edu; SCR's current address: Department of Astronomy and Space Sciences, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejeon 305-764, Korea
4 Center for Space Astrophysics, Yonsei University, Seoul 120-749, Korea; ywlee@csa.yonsei.ac.kr, yi@astro.ox.ac.uk
5 Laboratoire d'Astrophysique de Marseille, BP 8, Traverse du Siphon, 13376 Marseille Cedex 12, France; alessandro.boselli, jose, bruno.milliard@oamp.fr
6 Center for Astrophysical Sciences, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218; dthilker, bianchi@pha.jhu.edu
7 Department of Physics and Astronomy, University of California, Los Angeles, CA 90095; rmr@astro.ucla.edu
8 Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center, Greenbelt, MD 20771; neff@stars.gsfc.nasa.gov
9 Department of Physics and Astronomy, The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218; heckman, szalay@pha.jhu.edu


Abstract. We present images, integrated photometry, surface-brightness and color profiles for a total of 1034 nearby galaxies recently observed by the Galaxy Evolution Explorer (GALEX) satellite in its far-ultraviolet (FUV; lambdaeff = 1516 Å) and near-ultraviolet (NUV; lambdaeff = 2267 Å) bands. Our catalog of objects is derived primarily from the GALEX Nearby Galaxies Survey (NGS) supplemented by galaxies larger than 1arcmin in diameter serendipitously found in these fields and in other GALEX exposures of similar of greater depth. The sample analyzed here adequately describes the distribution and full range of properties (luminosity, color, Star Formation Rate; SFR) of galaxies in the Local Universe.

From the surface brightness profiles obtained we have computed asymptotic magnitudes, colors, and luminosities, along with the concentration indices C31 and C42. We have also morphologically classified the UV surface brightness profiles according to their shape. This data set has been complemented with archival optical, near-infrared, and far-infrared fluxes and colors.

We find that the integrated (FUV- K) color provides robust discrimination between elliptical and spiral/irregular galaxies and also among spiral galaxies of different sub-types. Elliptical galaxies with brighter K-band luminosities (i.e. more massive) are redder in (NUV- K) color but bluer in (FUV-NUV) (a color sensitive to the presence of a strong UV upturn) than less massive ellipticals. In the case of the spiral/irregular galaxies our analysis shows the presence of a relatively tight correlation between the (FUV-NUV) color (or, equivalently, the slope of the UV spectrum, beta) and the total infrared-to-UV ratio. The correlation found between (FUV-NUV) color and K-band luminosity (with lower luminosity objects being bluer than more luminous ones) can be explained as due to an increase in the dust content with galaxy luminosity.

The images in this Atlas along with the profiles and integrated properties are publicly available through a dedicated web page at /level5/GALEX_Atlas/


Keywords: galaxies: evolution - galaxies: fundamental parameters - galaxies: photometry - ultraviolet: galaxies - atlases


Table of Contents

INTRODUCTION

SAMPLE
Selection
Positions, sizes, morphological types, and distances

GALEX OBSERVATIONS
Comparison with a magnitude-limited sample

ANALYSIS
Color Images
Surface brightness and color profiles
Asymptotic magnitudes, colors, and structural parameters
Morphological classification of the UV profiles
Corollary data

RESULTS
Global statistical properties
Properties by morphological type
Color-magnitude and color-color diagrams
Dust extinction and the IRX- relation
Structural properties and UV morphology

CONCLUSIONS

FITS IMAGES

REFERENCES

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