  We present the first large-scale study of E+A (post-starburst) galaxies that
incorporates photometry in the ultraviolet (UV) wavelengths. We find that the
starburst that creates the E+A galaxy typically takes place within the last Gyr
and creates a high fraction (20-60 percent) of the stellar mass in the remnant
over a short timescale (< 0.1 Gyrs). We find a tight correlation between the
luminosity of our E+A galaxies and the implied star formation rate (SFR) during
the starburst. While low-luminosity E+As (M(z) > -20) exhibit implied SFRs of
less than 50 solar masses per year, their luminous counterparts (M(z) < -22)
shows SFRs greater than 300 and as high as 2000 solar masses per year,
suggesting that luminous and ultra-luminous infrared galaxies in the
low-redshift Universe could be the progenitors of massive nearby E+A galaxies.
We perform a comprehensive study of the characteristics of the quenching that
truncates the starburst in E+A systems.We find that, for galaxies less massive
than 10^10 MSun, the quenching efficiency decreases as the galaxy mass
increases. However, for galaxies more massive than 10^10 MSun, this trend is
reversed and the quenching efficiency increases with galaxy mass. Noting that
the mass threshold at which this reversal occurs is in excellent agreement with
the mass above which AGN become significantly more abundant in nearby galaxies,
we use simple energetic arguments to show that the bimodal behaviour of the
quenching efficiency is consistent with AGN and supernovae (SN) being the
principal sources of negative feedback above and below M ~ 10^10 MSun
respectively. (abridged)
