Igniting the Galaxy (Formation and evolution of giant molecular clouds in global galaxy disk simulations)
February 04, 2010
Abstract: While galactic interactions and the infall of diffuse gas are important processes, ultimately most of the gas in disk galaxies settles into a rotationally supported disk where the majority of the stellar population is born. How this gas evolves is key to understanding the interplay between a galaxy’s global properties and its star formation. The fact they are intimately related is evident in the Kennicutt-Schmidt relation; the emperical law relating the gas surface density of a galaxy to its star formation rate. Without understanding the evolution of the interstellar medium and the early processes of star formation, the origins of this law remain a mystery, leaving no choice but to rely on such observed correlations for an ever widening scene of models. Investigating such a link presents a challenge to simulators, who must model interactions over 4-5 orders of magnitude. In this talk, we show results from a high resolution (< 10 pc) global galaxy simulation that follows the formation and evolution of star-forming clouds. We present a technique to track the clouds through their life and compare their properties with observational results. We compare results for simulations with and without star formation and for runs with feedback from photoelectric heating.