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Title: Dark Matter Searches with the Fermi-LAT in the Direction of Dwarf Spheroidals

The dwarf spheroidal satellite galaxies of the Milky Way are some of the most dark-matter-dominated objects known. Due to their proximity, high dark matter content, and lack of astrophysical backgrounds, dwarf spheroidal galaxies are widely considered to be among the most promising targets for the indirect detection of dark matter via gamma rays. Here we report on gamma-ray observations of Milky Way dwarf spheroidal satellite galaxies based on 6 years of Fermi Large Area Telescope data processed with the new Pass 8 reconstruction and event-level analysis. None of the dwarf galaxies are significantly detected in gamma rays, and we present upper limits on the dark matter annihilation cross section from a combined analysis of the 15 most promising dwarf galaxies. The constraints derived are among the strongest to date using gamma rays, and lie below the canonical thermal relic cross section for WIMPs of mass ≲ 100GeV annihilating via the bb-bar and τ⁺τ⁻ channels.
Authors:
; ; ; ;
Publication Date:
OSTI Identifier:
1223227
Report Number(s):
FERMILAB-CONF--15-321-AE
arXiv eprint number arXiv:1507.03530; TRN: US1601473
DOE Contract Number:
AC02-07CH11359
Resource Type:
Conference
Resource Relation:
Conference: 34. International Cosmic Ray Conference, The Hague (Netherlands), 30 Jul - 6 Aug 2015
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; MILKY WAY; GAMMA RADIATION; NONLUMINOUS MATTER; ANNIHILATION; WIMPS; CROSS SECTIONS; COSMIC PHOTONS; SATELLITES; LIMITING VALUES; DETECTION; MASS