Testing the dark matter subhalo hypothesis of the gamma-ray source 3FGL J2212.5+0703

Abstract

N-body simulations predict that galaxies at the Milky Way scale host a large number of dark matter (DM) subhalos. Some of these subhalos, if they are massive enough or close enough to the Earth, might be detectable in $\gamma$ rays due to the DM annihilation. 3FGL J2212.5+0703, an unidentified gamma-ray source, has been suggested to be the counterpart candidate of a DM subhalo by Bertoni et al. (2015, 2016). In this work we analyze the Fermi-LAT Pass 8 data of 3FGL J2212.5+0703 to independently test the DM subhalo hypothesis of this source. In order to suppress the possible contamination from two nearby very-bright blazars, we just take into account the front-converting gamma-rays which have better angular resolutions than that of the back-converting photons. In addition to the spatial distribution analysis, we have extended the spectrum analysis down to the energies of $\sim 100$ MeV, and thoroughly examined the variability of the emission during the past 8 years. We confirm that 3FGL J2212.5+0703 is a steady and spatially-extended gamma-ray emitter at a high confidence level. The spectrum is well consistent with that expected from DM annihilation into $b\bar{b}$. The introduction of a phenomenological LogParabola spectrum just improves the fit slightly. All these results suggest that 3FGL J2212.5+0703 could be indicative of a DM subhalo.

8 pages, 4 figures. Accepted for publication in PRD

References in corpus (16)

• The NumPy array: a structure for efficient numerical computation
• Dark Matter Candidates from Particle Physics and Methods of Detection
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• Dark Matter and Collider Phenomenology of Universal Extra Dimensions
• A blueprint for detecting supersymmetric dark matter in the Galactic halo
• The Dark Matter Annihilation Signal from Galactic Substructure: Predictions for GLAST
• Hydra II: a faint and compact Milky Way dwarf galaxy found in the Survey of the Magellanic Stellar History
• A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
• A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3 pi Survey
• A Hero's Dark Horse: Discovery of an Ultra-Faint Milky Way Satellite in Pegasus
• Extracting limits on Dark Matter annihilation from gamma-ray observations towards dwarf spheroidal galaxies
• A model-independent analysis of the Fermi Large Area Telescope gamma-ray data from the Milky Way dwarf galaxies and halo to constrain dark matter scenarios
• Cosmic ray lepton puzzle in the light of cosmological N-body simulations
• Statistical Issues in Astrophysical Searches for Particle Dark Matter
• Search for gamma-ray line features from Milky Way satellites with Fermi-LAT Pass 8 data
• Gamma-rays From Warm WIMP Dark Matter Annihilation

Cited by in corpus (2)

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