3:30–5:00 pm ERC 161
Title: The nature of dark matter with stellar streams in the LSST era
Abstract: More than 130 stellar streams, long thin filaments of stars produced by tidal dissolution of star clusters and dwarf galaxies, have been discovered in the Milky Way halo. In addition to outlining the rich accretion history of the Milky Way, these streams are sensitive tracers of dark matter in the Galaxy. 3D positions and velocities of stream member stars identified in large kinematic surveys like Gaia and DESI have allowed us to constrain the mass and shape of the Milky Way's dark matter halo, with tantalizing evidence of a tilt with respect to the Galactic disk. Further, streams provide tentative evidence of dark matter substructure: a handful of best-observed streams have features consistent with impacts of low-mass dark-matter subhalos, although alternative explanations have not been ruled out fully. Upcoming facilities like the Vera Rubin Observatory's LSST (science verification in process) and the Via Project (first light in 2027) will provide more detailed observations of the structure and kinematics for a hundred stellar streams in the Milky Way halo. I will discuss how these data will isolate dark matter signals in stellar streams, constrain the linear matter power spectrum on scales below the threshold for galaxy formation (~10^6Msun), to ultimately explore dark matter particle candidates in the mass regime of <~25keV.
Zoom: https://uchicago.zoom.us/j/95163709101?pwd=n2tRNMeI5Cda1rL9rVCXL7eApjQJSl.1
