Events Daily

Wednesday, February 26, 2020

Blanton Tinker Pullen
Event Type: Blanton Tinker Pullen
Time: 1:00 PM - 2:00 PM
Location: 726 Broadway, 901, Sm Conf

Mapping dark matter with stellar streams: Signatures of dark matter substructure
Adrian Price-Whelan, Flatiron
Event Type: HEP Seminar
Time: 2:00 PM - 3:15 PM
Location: 726 Broadway, 940, CCPP Seminar
Description: Star clusters and dwarf galaxies erode and lose stars as they orbit within the tidal field of the Milky Way, leaving behind kinematically cold streams of stars. Stellar streams simulated in smooth, static approximations of the Milky Way have shown that they nearly trace out the orbit of their progenitor system and have relatively uniform density profiles, suggesting that they are simple yet informative tracers of the Galactic dark matter distribution. However, none of the known streams appear to be simple structures and instead display complex features and morphologies. In this talk, I will focus on one stream around the Milky Way -- the GD-1 stream -- that appears to have been gravitationally perturbed by at least one massive, dense object orbiting in the Galactic halo. No known baryonic objects have passed close enough to GD-1 to significantly affect its morphology, opening up the possibility that this stream has encountered a low-mass dark matter subhalo. The mere existence of such a subhalo would place strong constraints on the small-scale clustering of dark matter, demonstrating that stellar streams can deliver astrophysical constraints on particle theories of dark matter. I will discuss theoretical and observational challenges, along with a path forward, for repeating this type of analysis for a large sample of streams with the ultimate goal of measuring the subhalo mass function in a regime that will rule on the fundamental nature of dark matter.

Modjaz Group Mtg
Event Type: Modjaz Group Mtg
Time: 3:30 PM - 5:00 PM
Location: 726 Broadway, 901, Sm Conf

Astroparticle Group Mtg
Event Type: Astroparticle Group Mtg
Time: 3:30 PM - 5:30 PM
Location: 726 Broadway, 902, Lg Conf