TY - JOUR
T1 - Keck deimos spectroscopy of a GALEX UV-selected sample from the Medium Imaging Survey
AU - Mallery, Ryan P.
AU - Rich, R. Michael
AU - Salim, Samir
AU - Small, Todd
AU - Charlot, Stephane
AU - Seibert, Mark
AU - Wyder, Ted
AU - Barlow, Tom A.
AU - Forster, Karl
AU - Friedman, Peter G.
AU - Martin, D. Christopher
AU - Morrissey, Patrick
AU - Neff, Susan G.
AU - Schiminovich, David
AU - Bianchi, Luciana
AU - Donas, José
AU - Heckman, Timothy M.
AU - Lee, Young Wook
AU - Madore, Barry F.
AU - Milliard, Bruno
AU - Szalay, Alex S.
AU - Welsh, Barry Y.
AU - Yi, Sukyoung
PY - 2007/12
Y1 - 2007/12
N2 - We report results from a pilot program to obtain spectroscopy for objects detected in the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey (MIS). Our study examines the properties of galaxies detected by GALEX fainter than the Sloan Digital Sky Survey (SDSS) spectroscopic survey. This is the first study to extend the techniques of Salim and coworkers to estimate stellar masses, star formation rates (SFRs), and the b (star formation history) parameter for star-forming galaxies out to z ∼ 0.7. We obtain redshifts for 50 GALEXMlS sources reaching NUV = 23.9 (AB mag) having counterparts in the SDSS Data Release 4 (DR4). Of our sample, 43 are star-forming galaxies with z < 0.7,3 have emission-line ratios indicative of active galactic nuclei with z < 0.7, and 4 objects with z > 1 are QSOs, 3 of which are not previously cataloged. We compare our sample to a much larger sample of ∼50,000 matched GALEX/SGSS galaxies with SDSS spectroscopy; while our survey is shallow, the optical counterparts to our sources reach ∼3 mag fainter in SDSS r than the SDSS spectroscopic sample. We use emission-line diagnostics for the galaxies to determine that the sample contains mostly star-forming galaxies. The galaxies in the sample populate the blue sequence in the NUV - r versus Mr color-magnitude diagram. The derived stellar masses of the galaxies range from 108 to 1011 M⊙, and derived SFRs are between 10-1 and 102 M⊙ yr-1. Our sample has SFRs, luminosities, and velocity dispersions that are similar to the samples of faint compact blue galaxies studied previously in the same redshift range by Koo and collaborators, Guzmán and collaborators, and Phillips and collaborators. However, our sample is ∼2 mag fainter in surface brightness than the compact blue galaxies. We find that the star formation histories for a majority of the galaxies are consistent with a recent starburst within the last 100 Myr.
AB - We report results from a pilot program to obtain spectroscopy for objects detected in the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey (MIS). Our study examines the properties of galaxies detected by GALEX fainter than the Sloan Digital Sky Survey (SDSS) spectroscopic survey. This is the first study to extend the techniques of Salim and coworkers to estimate stellar masses, star formation rates (SFRs), and the b (star formation history) parameter for star-forming galaxies out to z ∼ 0.7. We obtain redshifts for 50 GALEXMlS sources reaching NUV = 23.9 (AB mag) having counterparts in the SDSS Data Release 4 (DR4). Of our sample, 43 are star-forming galaxies with z < 0.7,3 have emission-line ratios indicative of active galactic nuclei with z < 0.7, and 4 objects with z > 1 are QSOs, 3 of which are not previously cataloged. We compare our sample to a much larger sample of ∼50,000 matched GALEX/SGSS galaxies with SDSS spectroscopy; while our survey is shallow, the optical counterparts to our sources reach ∼3 mag fainter in SDSS r than the SDSS spectroscopic sample. We use emission-line diagnostics for the galaxies to determine that the sample contains mostly star-forming galaxies. The galaxies in the sample populate the blue sequence in the NUV - r versus Mr color-magnitude diagram. The derived stellar masses of the galaxies range from 108 to 1011 M⊙, and derived SFRs are between 10-1 and 102 M⊙ yr-1. Our sample has SFRs, luminosities, and velocity dispersions that are similar to the samples of faint compact blue galaxies studied previously in the same redshift range by Koo and collaborators, Guzmán and collaborators, and Phillips and collaborators. However, our sample is ∼2 mag fainter in surface brightness than the compact blue galaxies. We find that the star formation histories for a majority of the galaxies are consistent with a recent starburst within the last 100 Myr.
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U2 - 10.1086/516638
DO - 10.1086/516638
M3 - Article
AN - SCOPUS:39449110465
VL - 173
SP - 471
EP - 481
JO - Astrophysical Journal, Supplement Series
JF - Astrophysical Journal, Supplement Series
SN - 0067-0049
IS - 2
ER -