Fermi-LAT Sensitivity to Dark Matter Annihilation in Via Lactea II Substructure

We present a study of the ability of the Fermi Gamma-ray Space Telescope to detect dark matter (DM) annihilation signals from the Galactic subhalos predicted by the Via Lactea II N-body simulation. We implement an improved formalism for estimating the boost factor needed to account for the effect of DM clumping on scales below the resolution of the simulation, and we incorporate a detailed Monte Carlo simulation of the response of the Fermi-LAT, including a simulation of its all-sky observing mode integrated over a 10 year mission. We find that for WIMP masses up to about 150 GeV c -2 in standard supersymmetric models with lang�vrang = 3 × 10-26 cm3 s-1, a few subhalos could be detectable with >5 standard deviation significance and would likely deviate significantly from the appearance of a point source. DOI: https://doi.org/10.1088/0004-637X/718/2/899 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-41660 Accepted Version Originally published at: Anderson, B; Kuhlen, M; Diemand, J; Johnson, R P; Madau, P (2010). Fermi-LAT Sensitivity to Dark Matter Annihilation in Via Lactea II Substructure. Astrophysical Journal, 718(2):899-904. DOI: https://doi.org/10.1088/0004-637X/718/2/899 Fermi-LAT Sensitivity to Dark Matter Annihilation in Via Lactea II Substructure Brandon Anderson, Michael Kuhlen, Jürg Diemand, Robert Johnson, & Piero Madau [email protected], [email protected]