On Dark Matter Annihilation in the Local Group

Abstract

Under the hypothesis of a Dark Matter composed by supersymmetric particles like neutralinos, we investigate the possibility that their annihilation in the haloes of nearby galaxies could produce detectable fluxes of $\gamma$-photons. Expected fluxes depend on several, poorly known quantities such as the density profiles of Dark Matter haloes, the existence and prominence of central density cusps and the presence of a population of sub-haloes. We find that, for all reasonable choices of Dark Matter halo models, the intensity of the $\gamma$-ray flux from some of the nearest extragalactic objects, like M31, is comparable or higher than the diffuse Galactic foreground. We show that next generation ground-based experiments could have the sensitivity to reveal such fluxes which could help us unveiling the nature of Dark Matter particles.

11 pages, 10 figures. Accepted for publication in Phys. Rev. D.; added a new paragraph on the detectability of Galactic sub-halos in our Galaxy; added a discussion on their model dependence. The relation of our results with the "CDM crisis" issue has also been added

References in corpus (46)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• A Universal Density Profile from Hierarchical Clustering
• Supersymmetric Dark Matter
• Dark Matter Substructure in Galactic Halos
• Where are the missing galactic satellites?
• Dwarf Galaxies of the Local Group
• The Inner Structure of LambdaCDM Halos I: A Numerical Convergence Study
• Dark matter annihilation at the galactic center
• EGRET Observations of the Extragalactic Gamma Ray Emission
• Formation of Galactic Nuclei
• Observability of Gamma Rays from Dark Matter Neutralino Annihilations in the Milky Way Halo
• Density profiles and substructure of dark matter halos: converging results at ultra-high numerical resolution
• The Power Spectrum Dependence of Dark Matter Halo Concentrations
• The Central Mass Distribution in Dwarf and Low Surface Brightness Galaxies
• The Structural Evolution of Substructure
• Stellar Dynamics in the Galactic centre: Proper Motions and Anisotropy
• Neutralino Dark Matter in Focus Point Supersymmetry
• A Dark-Matter Spike at the Galactic Center?
• Cosmological dark matter annihilations into gamma-rays - a closer look
• Dwarf Galaxy Rotation Curves and the Core Problem of Dark Matter Halos
• Antideuterons as a Signature of Supersymmetric Dark Matter
• Simulating Observations of Dark Matter Dominated Galaxies: Towards the Optimal Halo Profile
• Small-scale clumps in the galactic halo and dark matter annihilation
• Dark matter annihilation in the halo of the Milky Way
• Dark Matter Spikes and Annihilation Radiation from the Galactic Center
• Prospects for Indirect Detection of Neutralino Dark Matter
• Spectral Gamma-ray Signatures of Cosmological Dark Matter Annihilation
• Evidence in Virgo for the Universal Dark Matter Halo
• The structure of dark matter halos in hierarchical clustering theories
• Supersymmetric Dark Matter in the Light of LEP and the Tevatron Collider
• The Clumpiness of Cold Dark Matter: Implications for the Annihilation Signal
• No Supermassive Black Hole in M33?
• High Energy Gamma--Radiation from the Galactic Center due to Neutralino Annihilation
• The phase-space structure of cold dark-matter halos: Insights into the Galactic halo
• The surface brightness of dark matter: unique signatures of neutralino annihilation in the Galactic halo
• Dark matter in Draco and the Local Group: Implications for direct detection experiments
• Which fraction of the measured cosmic-ray antiprotons might be due to neutralino annihilation in the galactic halo?
• The formation of galaxy stellar cores by the hierarchical merging of supermassive black holes
• Detection of Neutralino Annihilation Photons from External Galaxies
• Mass growth and density profiles of dark matter halos in hierarchical clustering
• Particle Dark Matter Constraints from the Draco Dwarf Galaxy
• Cusp Disruption in Minor Mergers
• Searching for TeV dark matter by atmospheric Cerenkov techniques
• Possible Indications of a Clumpy Dark Matter Halo
• Halo Dark Matter and Ultra-High Energy Cosmic Rays
• Galactic Gamma Halo by Heavy Neutrino annihilations?

Cited by in corpus (31)

• Particle Dark Matter: Evidence, Candidates and Constraints
• Dark Matter Detection in the Light of Recent Experimental Results
• Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments
• Dark Matter Candidates: A Ten-Point Test
• Implications of High-Resolution Simulations on Indirect Dark Matter Searches
• Neutralino annihilation into gamma-rays in the Milky Way and in external galaxies
• Dark Matter Dynamics and Indirect Detection
• Dark Matter Annihilation in Substructures Revised
• Constraining Very Heavy Dark Matter Using Diffuse Backgrounds of Neutrinos and Cascaded Gamma Rays
• Indirect Dark Matter Detection from Dwarf Satellites: Joint Expectations from Astrophysics and Supersymmetry
• Dark Matter and Gamma-Rays From Draco: MAGIC, GLAST and CACTUS
• Dark matter substructure modelling and sensitivity of the Cherenkov Telescope Array to Galactic dark halos
• Annihilation vs. Decay: Constraining dark matter properties from a gamma-ray detection
• Difficulty of detecting minihalos via $\gamma$-rays from dark matter annihilation
• Dark Matter and the CACTUS Gamma-Ray Excess from Draco
• Neutrinos from Dark Matter annihilations at the Galactic Centre
• Indirect search for dark matter: prospects for GLAST
• Evolution of Dark Matter Halos and their Radio Emissions
• Upper Limit on the Cosmological Gamma-ray Background
• Search for Gamma-rays from Dark Matter annihilations around Intermediate Mass Black Holes with the H.E.S.S. experiment
• Black Holes as Dark Matter Annihilation Boosters
• Gamma rays from the neutralino dark matter annihilations in the Milky Way substructures
• Testing the cosmic ray content in galaxy clusters
• Gamma-ray detection from neutralino annihilation in non--universal SUGRA scenarios
• Gamma-Rays from Dark Matter Mini-Spikes in M31
• Neutralino Annihilations and the Gas Temperature in the Dark Ages
• $\gamma$-ray flux from Dark Matter Annihilation in Galactic Caustics
• Determining Supersymmetric Parameters With Dark Matter Experiments
• Gamma ray and Neutrino fluxes from a cosmological dark matter simulation
• Detecting the dark matter annihilation at the ground EAS detectors
• Constraining supersymmetry from the satellite experiments