Speaker
Description
There is ample empirical evidence that galaxies’ star formation efficiency is nearly universal even across a wide range of galactic environments and metallicities. We use a suite of high-resolution hydrodynamics simulations of isolated galaxies at different metallicities to study how the cold, dense interstellar medium and star formation rate vary as a function of chemistry, ionizing radiation field strength, and smaller scale density fluctuations. We find that although the molecular hydrogen fraction depends sensitively on the local metallicity and far UV flux, the star formation efficiency per free-fall time does not. The simulations indicate that this universality arises due to the interplay between turbulent compression of gas and its subsequent dispersion due to feedback.
