Galaxy Evolution Explorer Ultraviolet Color-Magnitude Relations and Evidence of Recent Star Formation in Early-Type Galaxies

, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and

Published 2005 January 17 © 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A.
, , Citation S. K. Yi et al 2005 ApJ 619 L111 DOI 10.1086/422811

1538-4357/619/1/L111

Abstract

We have used the Galaxy Evolution Explorer UV photometric data to construct a first near-UV (NUV) color-magnitude relation (CMR) for the galaxies preclassified as early-type by Sloan Digital Sky Survey studies. The NUV CMR is a powerful tool for tracking the recent star formation history in early-type galaxies, owing to its high sensitivity to the presence of young stellar populations. Our NUV CMR for UV-weak galaxies shows a well-defined slope and thus will be useful for interpreting the rest-frame NUV data of distant galaxies and studying their star formation history. Compared to optical CMRs, the NUV CMR shows a substantially larger scatter, which we interpret as evidence of recent star formation activities. Roughly 15% of the recent epoch (z < 0.13) bright [M(r) < -22] early-type galaxies show a sign of recent (≲1 Gyr) star formation at the 1%-2% level (lower limit) in mass compared to the total stellar mass. This implies that low-level residual star formation was common during the last few billion years even in bright early-type galaxies.

Export citation and abstract BibTeX RIS

Please wait… references are loading.
10.1086/422811