Probing a dark matter density spike at the Galactic Center

Abstract

The dark matter halo profile in the inner Galaxy is very uncertain. Yet its radial dependence toward the Galactic Center is of crucial importance for the determination of the gamma-ray and radio fluxes originating from dark matter annihilations. Here we use synchrotron emission to probe the dark matter energy distribution in the inner Galaxy. We first solve the problem of the cosmic ray diffusion on very small scales, typically smaller than 10^{-3} pc, by using a Green's function approach and use this technique to quantify the effect of a spiky profile (rho(r) ~ r^{-7/3}) on the morphology and intensity of the synchrotron emission expected from dark matter. We illustrate our results using 10 and 800 GeV candidate weakly interacting dark matter particles annihilating directly into e+ e-. Our most critical assumptions are that the dark matter is heavier than a few GeV and directly produces a reasonable amount of electrons and positrons in the Galaxy. We conclude that dark matter indirect detection techniques (including the Planck experiment) could be used to shed light on the dark matter halo profile on scales that lie beyond the capability of any current numerical simulations.

14 pages, 9 figures, minor changes to match published version

References in corpus (9)

• Inverse Compton Origin of the Hard X-Ray and Soft Gamma-Ray Emission from the Galactic Ridge
• Gamma Ray Signals from Dark Matter: Concepts, Status and Prospects
• Galactic electrons and positrons at the Earth:new estimate of the primary and secondary fluxes
• Multi-wavelength signals of dark matter annihilations at the Galactic center
• Phenomenology of Dark Matter annihilation into a long-lived intermediate state
• Dark matter dynamics in Galactic center
• Regenerating WIMPs in the light of direct and indirect detection
• Can the morphology of gamma-ray emission distinguish annihilating from decaying dark matter?
• Clarifying the covariant formalism for the SZ effect due to relativistic non-thermal electrons

Cited by in corpus (23)

• Can environmental effects spoil precision gravitational-wave astrophysics?
• A review of indirect searches for particle dark matter
• A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
• Galactic Center Gamma-Ray Excess from Dark Matter Annihilation: Is There A Black Hole Spike?
• Dynamical constraints on a dark matter spike at the Galactic Centre from stellar orbits
• Fitting the Fermi-LAT GeV excess: On the importance of including the propagation of electrons from dark matter
• Post-Newtonian dynamical modeling of supermassive black holes in galactic-scale simulations
• Probing Dark Matter Spikes via Gravitational Waves of Extreme Mass Ratio Inspirals
• Exploring dark matter spike distribution around the Galactic centre with stellar orbits
• Sensitivity of CTA to dark matter signals from the Galactic Center
• Ruling out thermal dark matter with a black hole induced spiky profile in the M87 galaxy
• Discovery of a new extragalactic source population of energetic particles
• Waves from the Centre: Probing PBH and other Macroscopic Dark Matter with LISA
• Connecting the new H.E.S.S. diffuse emission at the Galactic center with the Fermi GeV excess: a combination of millisecond pulsars and heavy dark matter?
• Dark Matter Signatures of Supermassive Black Hole Binaries
• Listening for Dark Photon Radio from the Galactic Centre
• Illuminating Black Hole Shadow with Dark Matter Annihilation
• Universal Density and Velocity Distributions of Dark Matter around Massive Black Holes
• Compact Binary Merger Rate with Modified Gravity in Dark-Matter Spikes
• What Could be the Observational Signature of Dark Matter in Globular Clusters?
• On Equation of State of Dark Matter around Massive Black Holes
• LHAASO Galactic Plane $\gamma$-rays Strongly Constrain Heavy Dark Matter
• Fermionic Dark Matter spikes: origin and growth of Black Hole seeds