Evolution of Inner Halos: Disk Growth and First Generation of Galactic Bars

University Of Kentucky Research Foundation, Lexington KY

Investigators

Abstract

Dr. Shlosman will develop new methods to study how galaxies like our Milky Way form their disks inside halos of invisible 'dark matter'. He will examine how the density builds up in the central 'cusp' of the dark halo, and how the presence of the disk disturbs and changes that growth. The dark halo does not grow smoothly as the galaxy forms; it is usually lumpy and far from a well-mixed equilibrium. Dr Shlosman will use both gravitational N-body simulations and analytic calculations to follow the growth of disks in asymmetric and lumpy dark halos, and examine how bars are triggered in the stellar disk. The initial conditions for the N-body simulations will be set using the method of Constrained Realizations, an exact algorithm to construct the Gaussian random fields representing the distribution of matter at early times. The effects of interstellar gas, including energy dissipation, star formation, and the feedback of newly-born stars on the surrounding gas, will be taken into account. A graduate student will be trained by participating in the research. The University of Kentucky at Lexington has recently built an observatory for undergraduate teaching and public outreach. Dr Shlosman will participate in outreach programs at this observatory, illustrating the process of galaxy formation with animations developed from the computations that he will perform.