TUNA Lunch Talk:

Jon Bird


Inside Out and Upside Down: Tracing the Assembly of a Simulated Disk Galaxy Using Mono-Age Stellar Populations

May 28

12:10PM, Room 230, NRAO, Edgemont Road


The puzzle of disk galaxy formation, and the formation of the Milky Way itself, remains unsolved. I will present recent results in which we analyze the present-day structure and assembly history of a high resolution hydrodynamic simulation of the formation of a Milky Way (MW)-like disk galaxy, from the ``Eris'' simulation suite, dissecting it into cohorts of stars formed at different epochs of cosmic history. The oldest disk cohorts form in structures that are radially compact and relatively thick, while subsequent cohorts form in progressively larger, thinner, colder configurations from gas with increasing levels of rotational support. The disk thus forms ``inside-out'' in a radial sense and ``upside-down'' in a vertical sense. This assembly history is largely responsible for the galaxy's present-day correlations of stellar age with spatial and kinematic structure, which themselves are a good qualitative match to the observed correlations for mono-abundance stellar populations in the MW.