We present ultraviolet photometry for a sample of morphologically early-type galaxies selected by matching the Sloan Digital Sky Survey (SDSS) First Data Release with the Galaxy Evolution Explorer (GALEX) Medium and All-sky Imaging Surveys. We obtain a working sample of 1032 early-type galaxies with GALEX far-UV (FUV) detections, SDSS spectroscopy, and z < 0.2. Using the SDSS spectra to identify galaxies with even weak star formation or evidence of active galactic nuclei, and further removing galaxies with any evidence of non-early-type morphology, we derive a final sample of 172 red quiescent early-type galaxies. We find that the FUV - r color has a full range of 5 mag. Plotting the FUV - r color against the metallicity sensitive Lick Mg 2 and D4000 indices and against the stellar velocity dispersion, we find no correlation between our measurement of UV rising flux and any parameter sensitive to the global metallicity of quiescent early-type galaxies.
Bibliographical noteFunding Information:
GALEX (Galaxy Evolution Explorer) 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’Etudes Spatiales of France and the Korean Ministry of Science and Technology. We also acknowledge use of data from the Sloan Digital Sky Survey. The authors thank T. Brown and A. Renzini for valuable comments. J. B. acknowledges the support of an ESA postdoctoral fellowship.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science