Constraining Galactic dark matter with gamma-ray pixel counts statistics

Abstract

Gamma-ray searches for new physics such as dark matter are often driven by investigating the composition of the extragalactic gamma-ray background (EGB). Classic approaches to EGB decomposition manifest in resolving individual point sources and dissecting the intensity spectrum of the remaining unresolved component. Furthermore, statistical methods have recently been proven to outperform the sensitivity of classic source detection algorithms in finding point-source populations in the unresolved flux regime. In this article, we employ the 1-point photon count statistics of eight years of Fermi-LAT data to resolve the population of extragalactic point sources and to decompose the diffuse isotropic background contribution for Galactic latitudes |b|>30 deg. We use three adjacent energy bins between 1 and 10 GeV. For the first time, we extend the analysis to incorporate a potential contribution from annihilating dark matter smoothly distributed in the Galaxy. We investigate the sensitivity reach of 1-point statistics for constraining the thermally-averaged self-annihilation cross section <σv> of dark matter, using different template models for the Galactic foreground emission. Given the official Fermi-LAT interstellar emission model, we set upper bounds on the DM self-annihilation cross section <σv> that are comparable with the constraints obtained by other indirect detection methods, in particular by the stacking analysis of several dwarf spheroidal galaxies.

11 pages, 7 figures, 1 table; v2: major changes improving the selection of the ROI

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Cited by in corpus (17)

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• Dissecting the inner Galaxy with $\gamma$-ray pixel count statistics
• Testing gamma-ray models of blazars in the extragalactic sky
• Investigating the effect of Milky Way dwarf spheroidal galaxies extension on dark matter searches with Fermi-LAT data
• Dark Matter Density Profiles in Dwarf Galaxies: Linking Jeans Modeling Systematics and Observation
• Investigating the detection of dark matter subhalos as extended sources with Fermi-LAT
• A Compound Poisson Generator approach to Point-Source Inference in Astrophysics
• Flat spectrum radio quasars and BL Lacs dominate the anisotropy of the unresolved gamma-ray background
• Harnessing the Population Statistics of Subhalos to Search for Annihilating Dark Matter
• Multi-Component Imaging of the Fermi Gamma-ray Sky in the Spatio-spectral Domain
• Extracting the gamma-ray source-count distribution below the Fermi-LAT detection limit with deep learning
• How do the dynamics of the Milky Way -- Large Magellanic Cloud system affect gamma-ray constraints on particle dark matter?
• Characterizing the Expected Behavior of Non-Poissonian Template Fitting
• On the Energy Distribution of the Galactic Center Excess' Sources
• Deepening gamma-ray point-source catalogues with sub-threshold information