Unidentified gamma-ray sources as targets for indirect dark matter detection with the Fermi -Large Area Telescope

Journal Article · Fri Jul 12 00:00:00 EDT 2019 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2019/07/020· OSTI ID:1546970

Coronado-Blázquez, Javier ^[1]; Sánchez-Conde, Miguel A. ^[1]; Domínguez, Alberto ^[2]; Aguirre-Santaella, Alejandra ^[1]; Mauro, Mattia Di ^[3]; Mirabal, Néstor ^[4]; Nieto, Daniel ^[2]; Charles, Eric ^[5]

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1. Universidad Autónoma de Madrid (Spain)
2. Universidad Complutense de Madrid (Spain)
3. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); The Catholic Univ. of America, Washington, DC (United States)
4. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland Baltimore County (UMBC), Baltimore, MD (United States)
5. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States)

We report that one of the predictions of the ΛCDM cosmological framework is the hierarchical formation of structure, giving rise to dark matter (DM) halos and subhalos. When the latter are massive enough they retain gas (i.e., baryons) and become visible. This is the case of the dwarf satellite galaxies in the Milky Way (MW) . Below a certain mass, halos may not accumulate significant amounts of baryons and remain completely dark. However, if DM particles are Weakly Interacting Massive Particles (WIMPs), we expect them to annihilate in subhalos, producing gamma rays which can be detected with the Fermi satellite. Using the three most recent point-source Fermi Large Area Telescope (LAT) catalogs (3FGL, 2FHL and 3FHL), we search for DM subhalo candidates among the unidentified sources, i.e., sources with no firm association to a known astrophysical object. We apply several selection criteria based on the expected properties of the DM-induced emission from subhalos, which allow us to significantly reduce the list of potential candidates. Then, by characterizing the minimum detection flux of the instrument and comparing our sample to predictions from the Via Lactea II (VL-II) N-body cosmological simulation, we place conservative and robust constraints on the $$\langle$$σ v$$\rangle$$-m_DM parameter space. For annihilation via the τ⁺τ^- channel, we put an upper limit of 4 × 10^-26 (5 × 10^-25) cm³s^-1 for a mass of 10 (100) GeV . A critical improvement over previous treatments is the repopulation we made to include low-mass subhalos below the VL\nobreakdash-II mass resolution. Finally, with more advanced subhalo candidate filtering the sensitivity reach of our method can potentially improve these constraints by a factor 3 (2) for τ⁺τ^- (b_$$\bar{b}$$) channel.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1546970
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2019, Issue 07; ISSN 1475-7516
• Publisher: Institute of Physics (IOP)
• Country of Publication: United States
• Language: English

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79 ASTRONOMY AND ASTROPHYSICS