Title: The Core Size of WDM Haloes

Speaker: Shao Shi (National Astronomical Observatories)　　

Time: 3:00PM, March 31(Saturday)

Place: Main building, A511

Abstract: Warm dark matter model predicts cored structures of Dark Matter haloes, in stark contrast to the cuspy shape of its Cold Dark Matter counterpart. Because the cores of dark matter haloes in realistic warm dark matter model are predicted to be very small and computationally challenging to be resolved in current generation of numerical simulations, we have performed a set of constrained numerical experiments to investigate how the initial velocity dispersion of warm dark matter particles influence the final real and phase space structure of dark matter haloes. As expected the inner density profile of warm dark matter haloes are well approximated with a cored-isothermal profile, their maximum coarse-grained phase space density measured from our simulations is very close to the predicted primordial bound set by particles physics. Finally we revise the lower limit of warm dark matter particles with a combination of observational data and our results and conclude that realistic warm dark matter alone is not capable to explain core size of LSB galaxies, baryonic physics is required.