Tracing the evolution of nearby early-type galaxies in low density   environments. The Ultraviolet view from GALEX
  We detected recent star formation in nearby early-type galaxies located in low density environments, with GALEX Ultraviolet (UV) imaging. Signatures of star formation may be present in the nucleus and in outer rings/arm like structures. Our study suggests that such star formation may be induced by different triggering mechanisms, such as the inner secular evolution driven by bars, and minor accretion phenomena. We investigate the nature of the (FUV-NUV) color vs. Mg2 correlation, and suggest that it relates to "downsizing" in galaxy formation. 
R. Rampazzo, F. Annibali, A. Marino, L. Bianchi, A. Bressan, L.M.   Buson, M. Clemens, P. Panuzzo, W.W. Zeilinger
astro-ph.CO