New Fermi-LAT Results on the Search for Dark Matter Annihilation in Dwarf Spheroidal Galaxies

by Dr Matthew Wood (SLAC)

Tuesday 14 Oct 2014, 12:30 → 13:30 US/Pacific

Kavli 3 (SLAC)

Dwarf Spheroidal galaxies of the Milky Way are a compelling target for indirect dark matter (DM) searches due to their large DM content and low astrophysical backgrounds. The annihilation or decay of DM particles in these objects may produce gamma rays with energies up to the DM particle rest mass. Launched in 2008, the Fermi Large Area Telescope (LAT) is an imaging, wide field-of-view, gamma-ray telescope that is sensitive in the energy range from 20 MeV to more than 300 GeV. The LAT has excellent sensitivity to the gamma-ray signatures of DM models in the theoretically preferred mass range between 10 GeV and 10 TeV and provides a probe of these models that is complementary to direct detection and collider searches. I will describe a likelihood-based stacking analysis that combines LAT data from multiple dwarf galaxies to search for gamma-ray emission from the annihilation of DM particles. Limits derived from a previous stacking analysis using four years of LAT data currently provide some of the most stringent constraints on the DM annihilation cross section. In this talk I will report on a new analysis of dwarf spheroidal galaxies using five years of LAT data reprocessed with an improved event-level reconstruction.

pictures fermi_lat_sky_dwarfs.png wood.jpg

Slides slac_seminar_lat_dsph_searches_141014_v3.pdf