Neutralino Gamma-ray Signals from Accreting Halo Dark Matter

Abstract

There is mounting evidence that a self-consistent model for particle cold dark matter has to take into consideration spatial inhomogeneities on sub-galactic scales seen, for instance, in high-resolution N-body simulations of structure formation. Also in more idealized, analytic models, there appear density enhancements in certain regions of the halo. We use the results from a recent N-body simulation of the Milky Way halo and investigate the gamma-ray flux which would be produced when a specific dark matter candidate, the neutralino, annihilates in regions of enhanced density. The clumpiness found on all scales in the simulation results in very strong gamma-ray signals which seem to already rule out some regions of the supersymmetric parameter space, and would be further probed by upcoming experiments, such as the GLAST gamma-ray satellite. As an orthogonal model of structure formation, we also consider Sikivie's simple infall model of dark matter which predicts that there should exist continuous regions of enhanced density, caustic rings, in the dark matter halo of the Milky Way. We find, however, that the gamma-ray signal from caustic rings is generally too small to be detectable.

15 pages, 11 figures

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Cited by in corpus (40)

• Particle Dark Matter: Evidence, Candidates and Constraints
• DarkSUSY: Computing Supersymmetric Dark Matter Properties Numerically
• The first WIMPy halos
• The power spectrum of SUSY-CDM on sub-galactic scales
• Small-scale clumps in the galactic halo and dark matter annihilation
• Dark Matter Candidates: A Ten-Point Test
• Spectral Gamma-ray Signatures of Cosmological Dark Matter Annihilation
• Neutrino Constraints on the Dark Matter Total Annihilation Cross Section
• Anisotropy of the cosmic gamma-ray background from dark matter annihilation
• Neutralino annihilation into gamma-rays in the Milky Way and in external galaxies
• Dark Matter Dynamics and Indirect Detection
• The Galactic Center as a Dark Matter Gamma-Ray Source
• The fine-grained phase-space structure of Cold Dark Matter halos
• The Detectability of Neutralino Clumps via Atmospheric Cherenkov Telescopes
• The Caustic Ring Model of the Milky Way Halo
• Two photon annihilation of Kaluza-Klein dark matter
• Evidence for Ring Caustics in the Milky Way
• Can Dark Matter Annihilation Dominate the Extragalactic Gamma-Ray Background?
• Can Supersymmetry Naturally Explain the Positron Excess?
• Limits on Supersymmetric Dark Matter From EGRET Observations of the Galactic Center Region
• Direct and Indirect Detection of Neutralino Dark Matter In Selected Supersymmetry Breaking Scenarios
• Infall caustics in dark matter halos?
• Gravitational cooling and density profile near caustics in collisionless dark matter haloes
• A potential WIMP signature for the caustic ring halo model
• Dark matter annihilation from intermediate-mass black holes: Contribution to the extragalactic gamma-ray background
• Robustness of Discrete Flows and Caustics in Cold Dark Matter Cosmology
• Searching For Dark Matter with Neutrino Telescopes
• Does the Second Caustic Ring of Dark Matter Cause the Monoceros Ring of Stars ?
• Search for TeV gamma ray emission from the Andromeda galaxy
• Cosmological gamma ray and neutrino backgrounds due to neutralino dark matter annihilation
• Known Unknowns of Dark Matter Annihilation over Cosmic Time
• Galactic-Centre Gamma Rays in CMSSM Dark Matter Scenarios
• Anisotropy of dark matter annihilation with respect to the Galactic plane
• Improving the Angular Resolution of EGRET and New Limits on Supersymmetric Dark Matter Near the Galactic Center
• A further look at particle annihilation in dark matter caustics
• $\gamma$-ray flux from Dark Matter Annihilation in Galactic Caustics
• Dense gas clouds and the Unidentified EGRET sources
• WIMP annihilation in caustics
• Resolving infall caustics in dark matter halos
• Smallest Halos in Thermal Wino Dark Matter