Spectral and spatial analysis of the dark matter subhalo candidates among Fermi Large Area Telescope unidentified sources

Journal Article · 28 November 2019 · Journal of Cosmology and Astroparticle Physics

DOI: https://doi.org/10.1088/1475-7516/2019/11/045 · OSTI ID:1608811

Coronado-Blázquez, Javier ^[1]; Sánchez-Conde, Miguel A. ^[1]; Mauro, Mattia Di ^[2]; Aguirre-Santaella, Alejandra ^[1]; Ciucă, Ioana ^[3]; Domínguez, Alberto ^[4]; Kawata, Daisuke ^[3]; Mirabal, Néstor ^[5]

---

1. Univ. Autonoma de Madrid (Spain). Inst. de Fisica Teorica and Dept. de Fisica Teorica
2. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Catholic Univ. of America, Washington, DC (United States)
3. Univ. College London (UCL), Surrey (United Kingdom). Mullard Space Science Lab. (MSSL)
4. Univ. Complutense Madrid (Spain)
5. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland Baltimore County (UMBC), Baltimore, MD (United States)

Fermi-LAT unidentified sources (unIDs) have proven to be compelling targets for performing indirect dark matter (DM) searches. In a previous work, we found that among the 1235 unIDs in Fermi-LAT's catalogs (3FGL, 2FHL and 3FHL) only 44 of those are DM subhalos candidates. In the present work, we implement a spectral analysis to test whether these remaining sources are compatible or not with DM origin. This analysis is executed using almost 10 years of Pass 8 Fermi-LAT data. None of the unIDs are found to significantly prefer DM-induced emission compared to other, more conventional, astrophysical sources. In order to discriminate between pulsar and DM sources, we developed a new method which is based on the source's spectral curvature, peak energy, and its detection significance. We also look for spatial extension, which may be a hint for a DM origin according to our N-body simulation studies of the subhalo population. In addition, we used Gaia DR2 data to search for a potential stellar counterpart to our best DM subhalo candidates and, although no firm associations could be found, one of them coincides with the Sagittarius stream. Finally, previous constraints on the DM annihilation cross section are updated with the new number of remaining DM subhalo candidates among unIDs. Our limits now rule out canonical thermal WIMPs up to masses of 10 GeV for b and 20 GeV for τ⁺τ^– annihilation channels, in this way being as sensitive and complementary to those obtained from other targets and probes.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE; Comunidad de Madrid; National Aeronautics and Space Administration (NASA); Science and Technology Facilities Council (STFC); Ministry of Economic Affairs and Digital Transformation of Spain (MINECO); Agencia Estatal de Investigacion
• Grant/Contract Number: AC02-76SF00515; 2016-T1/TIC- 1542; PGC2018-095161-B-I00; SEV-2016-0597; FPA2017-90566-REDC
• OSTI ID: 1608811
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2019, Issue 11; ISSN 1475-7516
• Publisher: Institute of Physics (IOP)Copyright Statement
• Country of Publication: United States
• Language: English