Multi-phase outflows in post starburst E+A galaxies -- I. General wind properties and the prevalence of starbursts.

E+A galaxies are believed to be a short phase connecting major merger ULIRGs with red and dead elliptical galaxies. Their optical spectrum suggests a massive starburst that was quenched abruptly, and their bulge-dominated morphologies with tidal tails suggest that they are merger remnants. AGN-driven winds are believed to be the process responsible for the sudden quenching of star formation and for the expulsion and/or destruction of the remaining molecular gas. So far, little was known observationally about AGN-driven winds in this short-lived phase. In this paper we present the first sample of E+A galaxies with AGN and indications of ionized outflows. Using IRAS-FIR observations, we study the star formation in these systems and find that, contrary to common belief, many E+A galaxies are not fully-quenched, with some showing powerful starbursts that are completely obscured at optical wavelengths. Using SDSS spectroscopy, we study the stationary and outflowing ionized gas. We also detect neutral gas outflows in 40\% of the sources. In these objects, the neutral outflow phase is 10--100 times more massive than the ionized phase. The mass outflow rate and kinetic power of the ionized outflows in E+A galaxies ($\dot{M}\sim 1\, \mathrm{M_{\odot}/yr}$, $\dot{E}\sim 10^{41}\, \mathrm{erg/sec}$) are larger than those derived for typical active galaxies. For the neutral outflow ($\dot{M}\sim 10\, \mathrm{M_{\odot}/yr}$, $\dot{E}\sim 10^{42}\, \mathrm{erg/sec}$) , they are smaller than those observed in (U)LIRGs with and without AGN. Our partial correlation analysis suggests that both AGN and SF contribute to the observed winds.