Life and Death at Cosmic High Noon
Marcin Sawicki



Galaxies are giant machines that turn gas into stars and the rate at which they were doing this was highest around redshift z=2, when the universe was only 1/4 of its present age. This is "cosmic high noon", and I will discuss both star-forming (live) and quiescent (dead) galaxies at z~2. My choice of this live/dead terminology here is not just a fanciful analogy but is central to my talk: I will show how the starforming-to-quiescent transition follows rules that are very similar to those that govern human death, leading not only to a well-justified "live/dead" terminology for star forming and quiescent galaxies, but to a simple and direct explanation for the Schechter-like stellar mass function for massive galaxies and potential insights into the quenching mechanism itself.