Speaker
Description
In this talk I will present results from the FIRE cosmological zoom-in simulations exploring the (un)changing properties of the ISM through cosmic time, from redshift three to zero. I will highlight how on (sub)kiloparsec scales, several important properties of the ISM do not change as the galaxies grow and evolve from dispersion-supported, star-bursting objects to rotation-supported, smoothly star-forming disks. In particular, the importance of equilibria and stability against gravitational fragmentation and collapse on the gas scale height will be discussed. Intriguingly, gas appears to arrange itself with feedback in a manner so as to maintain marginal stability, regardless of the large-scale galaxy morphology, provided the entire gas reservoir is not being affected by a major merger. For this reason, I will show how though many variables are changing across the history of these galaxies, e.g., star formation rates, gas fractions, how feedback is coupling to the ISM, turbulent gas velocity dispersions, cold gas fractions, the underlying (dynamic) equilibrium of the ISM is not. Lastly, I will point to observational consequences of this underlying dynamical equilibrium that will be testable by the current and next generation of IFU surveys of extragalactic gas, star formation, and feedback on the sub-kiloparsec scale.
