Title: Examining The Fermi-LAT Third Source Catalog in search of dark matter subhalos

Abstract

Dark matter annihilations taking place in nearby subhalos could appear as gamma-ray sources without detectable counterparts at other wavelengths. In this study, we consider the collection of unassociated gamma-ray sources reported by the Fermi Collaboration in an effort to identify the most promising dark matter subhalo candidates. While we identify 24 bright, high-latitude, non-variable sources with spectra that are consistent with being generated by the annihilations of ∼ 20–70 GeV dark matter particles (assuming annihilations to b b-bar ), it is not possible at this time to distinguish these sources from radio-faint gamma-ray pulsars. Deeper multi-wavelength observations will be essential to clarify the nature of these sources. It is notable that we do not find any such sources that are well fit by dark matter particles heavier than ∼100 GeV. We also study the angular distribution of the gamma-rays from this set of subhalo candidates, and find that the source 3FGL J2212.5+0703 prefers a spatially extended profile (of width ∼ 0.15°) over that of a point source, with a significance of 4.2σ (3.6σ after trials factor). Although not yet definitive, this bright and high-latitude gamma-ray source is well fit as a nearby subhalo of m{sub χ} ≅ 20–50 GeV dark matter particlesmore » (annihilating to b b-bar ) and merits further multi-wavelength investigation. Based on the subhalo distribution predicted by numerical simulations, we derive constraints on the dark matter annihilation cross section that are competitive to those resulting from gamma-ray observations of dwarf spheroidal galaxies, the Galactic Center, and the extragalactic gamma-ray background.« less

Authors:

Bertoni, Bridget ^[1]; Hooper, Dan ^[2]; Linden, Tim ^[3]

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+ Show Author Affiliations

1. Department of Physics, University of Washington, Seattle, WA 98195 (United States)
2. Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)
3. Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States)

Publication Date:

2015-12-01

OSTI Identifier:

22525118

Resource Type:

Journal Article

Journal Name:

Journal of Cosmology and Astroparticle Physics

Additional Journal Information:

Journal Volume: 2015; Journal Issue: 12; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516

Country of Publication:

United States

Language:

English

Subject:

79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANGULAR DISTRIBUTION; ANNIHILATION; CATALOGS; COMPUTERIZED SIMULATION; COSMIC GAMMA SOURCES; CROSS SECTIONS; GALAXIES; GAMMA RADIATION; GEV RANGE; INTERGALACTIC SPACE; LIMITING VALUES; NONLUMINOUS MATTER; PULSARS