Galaxies are remarkably diverse in their properties, ranging from irregular to disky to elliptical in morphology, and from blue to red in color. At the same time, when analyzed systematically, galaxy populations exhibit striking regularities, with clear trends with mass and redshift. How does this “regular complexity” emerge from the hot Big Bang? I will present results from the FIRE simulations which shed some light onto the processes that shape galaxies. The FIRE zoom-in simulations resolve the multiphase interstellar medium of galaxies and model several different feedback processes (including Type II/Ia supernovae, stellar winds, and radiation) while including the cosmological environment. I will highlight recent results on the formation of galactic disks, the “burstiness” of star formation, galactic winds, and the growth of supermassive black holes. Our new results indicate that transitions in the properties of each of these important phenomena can be simultaneously explained by a phase transition (virialization) in the inner circumgalactic medium, and arise from the interplay between feedback energy produced on small scales and the physics of halo gas on larger scales.
Host: Rob Simcoe