IAU Symposium Abstract S186-029T


The Environment and Evolution of ``E+A" Galaxies


Ann I. Zabludoff1, Dennis Zaritsky2
1 University of California, Santa Cruz, CA, USA < aiz@moriarty.ucolick.org >
2 University of California, Santa Cruz, CA, USA < dennis@alphalfa.ucolick.org >



The spectrum of an ``E+A" galaxy, which is dominated by a young stellar component but lacks the emission lines characteristic of any significant, on-going star formation, suggests that the galaxy experienced a brief, powerful starburst within the last Gyr. In past work, this violent star formation history and the detection of these galaxies almost exclusively in distant clusters linked them to the ``Butcher-Oemler effect'' and argued for the influence of cluster environment in the evolution of galaxies. However, no statistical survey of the environments of ``E+A''s had ever been made. From 11113 galaxy spectra in the Las Campanas Redshift Survey, we have obtained a unique and well-defined sample of 21 nearby ``E+A" galaxies with the same spectral characteristics as ``E+A"s in distant clusters. We are now studying this sample with complementary HST and VLA observations. In my talk, I will discuss the environments of ``E+A"s, the implications for how these galaxies evolve, and what their spectral features tell us about their recent star formation history.