Characterization of Dark-Matter-induced anisotropies in the diffuse gamma-ray background

Abstract

The Fermi-LAT collaboration has recently reported the detection of angular power above the photon noise level in the diffuse gamma-ray background between 1 and 50 GeV. Such signal can be used to constrain a possible contribution from Dark-Matter-induced photons. We estimate the intensity and features of the angular power spectrum (APS) of this potential Dark Matter (DM) signal, for both decaying and annihilating DM candidates, by constructing template all-sky gamma-ray maps for the emission produced in the galactic halo and its substructures, as well as in extragalactic (sub)halos. The DM distribution is given by state-of-the-art N-body simulations of cosmic structure formation, namely Millennium-II for extragalactic (sub)halos, and Aquarius for the galactic halo and its subhalos. We use a hybrid method of extrapolation to account for (sub)structures that are below the resolution limit of the simulations, allowing us to estimate the total emission all the way down to the minimal self-bound halo mass. We describe in detail the features appearing in the APS of our template maps and we estimate the effect of various uncertainties such as the value of the minimal halo mass, the fraction of substructures hosted in a halo and the shape of the DM density profile. Our results indicate that the fluctuation APS of the DM-induced emission is of the same order as the Fermi-LAT APS, suggesting that one can constrain this hypothetical emission from the comparison with the measured anisotropy. We also quantify the uncertainties affecting our results, finding "theoretical error bands" spanning more than two orders of magnitude and dominated (for a given particle physics model) by our lack of knowledge of the abundance of low-mass (sub)halos.

24 pages, 13 figures

References in corpus (32)

• The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
• New Gamma-Ray Contributions to Supersymmetric Dark Matter Annihilation
• Gamma-ray and radio tests of the e+e- excess from DM annihilations
• What mass are the smallest protohalos?
• The Fermi-LAT high-latitude Survey: Source Count Distributions and the Origin of the Extragalactic Diffuse Background
• Erasing Dark Matter Cusps in Cosmological Galactic Halos with Baryons
• Galactic electrons and positrons at the Earth:new estimate of the primary and secondary fluxes
• The Dark Matter Annihilation Signal from Galactic Substructure: Predictions for GLAST
• A new determination of the local dark matter density from the kinematics of K dwarfs
• Detecting dark matter WIMPs in the Draco dwarf: a multi-wavelength perspective
• Early supersymmetric cold dark matter substructure
• Dark Matter Annihilation in Substructures Revised
• Indirect Dark Matter Detection from Dwarf Satellites: Joint Expectations from Astrophysics and Supersymmetry
• The fine-grained phase-space structure of Cold Dark Matter halos
• Galactic Substructure and Dark Matter Annihilation in the Milky Way Halo
• Dark matter annihilation or unresolved astrophysical sources? Anisotropy probe of the origin of cosmic gamma-ray background
• 3D Distribution of Molecular Gas in the Barred Milky Way
• Galactic Substructure and Direct Detection of Dark Matter
• Cosmic Gamma-Ray Background from Star-Forming Galaxies
• Extragalactic Inverse Compton Light from Dark Matter Annihilation and the Pamela Positron Excess
• Anisotropy probe of galactic and extra-galactic Dark Matter annihilations
• Can Dark Matter Annihilation Dominate the Extragalactic Gamma-Ray Background?
• Contribution from Star-Forming Galaxies to the Cosmic Gamma-Ray Background Radiation
• Angular Signatures of Annihilating Dark Matter in the Cosmic Gamma-Ray Background
• Angular power spectrum of gamma-ray sources for GLAST: blazars and clusters of galaxies
• The cosmic X-ray and gamma-ray background from dark matter annihilation
• The Extragalactic Gamma Ray Background
• Constraining Dark Matter in Galactic Substructure
• Leptons from Dark Matter Annihilation in Milky Way Subhalos
• Can the morphology of gamma-ray emission distinguish annihilating from decaying dark matter?
• Contribution from unresolved discrete sources to the Extragalactic Gamma-Ray Background (EGRB)
• The spherical collapse model with shell crossing

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• The Origin of the Extragalactic Gamma-Ray Background and Implications for Dark-Matter Annihilation
• Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background
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• Sensitivity Projections for Dark Matter Searches with the Fermi Large Area Telescope
• The Dark Matter Annihilation Boost from Low-Temperature Reheating
• Indirect dark matter searches in Gamma- and Cosmic Rays
• Small-scale clumps of dark matter
• Indirect Detection Analysis: Wino Dark Matter Case Study
• Diffuse gamma-ray emission from galactic pulsars
• CLUMPY: Jeans analysis, $\gamma$-ray and neutrino fluxes from dark matter (sub-)structures
• High-energy gamma-ray and neutrino backgrounds from clusters of galaxies and radio constraints
• A novel approach in the WIMP quest: Cross-Correlation of Gamma-Ray Anisotropies and Cosmic Shear
• Halo Substructure Boosts to the Signatures of Dark Matter Annihilation
• Dark matter searches in the gamma-ray extragalactic background via cross-correlations with galaxy catalogues
• The angular power spectrum of the diffuse gamma-ray emission as measured by the Fermi Large Area Telescope and constraints on its Dark Matter interpretation
• Particle dark matter searches in the anisotropic sky
• Mapping dark matter in the gamma-ray sky with galaxy catalogs
• Resolving Small-Scale Dark Matter Structures Using Multi-Source Indirect Detection
• Dark matter substructure modelling and sensitivity of the Cherenkov Telescope Array to Galactic dark halos
• Galactic PeV neutrinos from dark matter annihilation
• Tomographic-spectral approach for dark matter detection in the cross-correlation between cosmic shear and diffuse gamma-ray emission
• Dissecting the Gamma-Ray Background in Search of Dark Matter
• Power spectrum tomography of dark matter annihilation with local galaxy distribution
• Cross-correlation of weak lensing and gamma rays: implications for the nature of dark matter
• Constraints on dark matter annihilations from diffuse gamma-ray emission in the Galaxy
• Impact of axisymmetric mass models for dwarf spheroidal galaxies on indirect dark matter searches
• Tomographic imaging of the Fermi-LAT gamma-ray sky through cross-correlations: A wider and deeper look
• Characterizing the local gamma-ray Universe via angular cross-correlations
• Separating astrophysical sources from indirect dark matter signals
• Clustering in the Phase Space of Dark Matter Haloes. II. Stable Clustering and Dark Matter Annihilation
• MultiDark-Clusters: Galaxy Cluster Mock Light-Cones, eROSITA and the Cluster Power Spectrum
• Dark Matter implications of Fermi-LAT measurement of anisotropies in the diffuse gamma-ray background
• Astrophysical interpretation of the anisotropies in the unresolved gamma-ray background
• Gamma-ray anisotropies from dark matter in the Milky Way: the role of the radial distribution
• Constraints on dark matter annihilation and decay from the large-scale structure of the nearby universe
• Diffuse Gamma Ray Background from Annihilating Dark Matter in Density Spikes around Supermassive Black Holes
• A decade of dark matter searches with ground-based Cherenkov telescopes
• Future sensitivity of neutrino telescopes to dark matter annihilations from the cosmic diffuse neutrino signal
• The sensitivity of Cherenkov telescopes to dark matter and astrophysical anisotropies in the diffuse gamma-ray background
• Novel Techniques for Decomposing Diffuse Backgrounds
• Isotropic extragalactic flux from dark matter annihilations: lessons from interacting dark matter scenarios
• Neutron star mass in dark matter clumps
• Harnessing the Population Statistics of Subhalos to Search for Annihilating Dark Matter
• Dark matter indirect detection signals and the nature of neutrinos in the supersymmetric $U(1{)}_{B-L}$ extension of the standard model
• Can galactic dark matter substructure contribute to the cosmic gamma-ray anisotropy?
• Observing small-scale $\gamma$-ray anisotropies with the Cherenkov Telescope Array
• The Dark Matter Contribution to Galactic Diffuse Gamma Ray Emission
• The Galactic Isotropic $\gamma$-ray Background and Implications for Dark Matter
• Search for Galactic dark matter substructures with Cherenkov telescopes
• Solving small-scale clustering problems in approximate lightcone mocks