Feedback from Starburst and Active Galaxies over Cosmic Time

 

 

Despite the success of the LCDM model describing the assembly of dark-matter in the Universe, predicting the properties of galaxies and the intergalactic medium (IGM) still require {\it empirical recipes} that account for baryonic physics. Challenges include accounting for the dispersal of metals in the intergalactic medium, supressing star formation in both massive halos (the overcooling problem) and dwarf galaxies (the satellite problem), and explaining the shift in star formation activity from more massive galaxies toward less massive galaxies with cosmic time (downsizing). Substantial progress has been made toward quantifying how much reheating from supernovae and supermassive black holes is required in cosmological simulations to solve these problems, but most models offer little direct insight into the mechanism(s). In this talk, I will describe measured properties of this feedback at three distinct eras. I will discuss the origin of outflows in nearby, ultraluminous starburst/AGN systems, the size of metal-enriched regions in the IGM at redshift 2-3, and the nature of the objects that ionize the IGM at redshift 6.

 

 

Crystal Martin