|Speaker: Emil Polisensky (NRL)
Title: Probing Dark Matter at Small Scales with N-body Simulations
Abstract: Observations of the large scale matter and energy distribution in the Universe have set LCDM as the standard model of cosmology yet the identity of the dark matter particle remains unknown. Probes of the matter power spectrum on sub-Mpc scales can potentially yield information on the nature of the dark matter. We have conducted N-body simulations of the growth of Milky Way-sized halos in cold and warm dark matter cosmologies. The satellite abundances in our simulated Milky Ways decreases with decreasing dark matter particle mass. Assuming the number of dark matter satellites exceeds or equals the number of observed satellites, we derive robust lower limits on the dark matter particle mass. The recent discovery of many new dark matter dominated satellites in the Sloan Digital Sky Survey allows us to set lower limits comparable to constraints from complementary methods. WDM also affects the structures of the dark matter halos and can alleviate discrepancies between the most massive satellites in simulations and the observed dynamics of the brightest Milky Way satellites. I will also discuss an application of our CDM simulations to deep observations of neutral hydrogen in nearby galaxy groups to explore an association between HI clouds and dark matter halos.
|Date||April 20, 2012|
|Start/End Time||03:00 PM - 04:00 PM|
|Location||UMD Astro Library|