I will present the fruition of a 3-year program to create realistic galaxy-sized models of stars and gas that include all ISM phases from first principles, as well as a star-formation process and criteria that realistically couples them to the stellar component.
An H2-regulated star formation process, along with the inclusion of its CO-bright phase (not the same thing), allows a new feedback factor to be monitored (far-UV light from newborn stars) and a dynamical examination of the Schmidt-Kennicut empirical relations linking gas and star-formation in galaxies. We find robust examples of deviations, more likely to be encountered in gas-rich, Early-Universe galaxies. Such relations are thus a poor choice of subgrid physics of star formation in cosmological structure formation models.
