Dark Matter Identification with Gamma Rays from Dwarf Galaxies

Abstract

If the positron fraction and combined electron-positron flux excesses recently observed by PAMELA, FERMI and HESS are due to dark matter annihilation into lepton-rich final states, the accompanying final state radiation (FSR) photons may be detected by ground-based atmospheric Cherenkov telescopes (ACTs). Satellite dwarf galaxies in the vicinity of the Milky Way are particularly promising targets for this search. We find that current and near-future ACTs have an excellent potential for discovering the FSR photons from dwarfs, although a discovery cannot be guaranteed due to large uncertainties in the fluxes resulting from lack of precise knowledge of dark matter distribution within the dwarfs. We also investigate the possibility of discriminating between different dark matter models based on the measured FSR photon spectrum. For typical parameters, we find that the ACTs can reliably distinguish models predicting dark matter annihilation into two-lepton final states from those favoring four-lepton final states (as in, for example, "axion portal" models). In addition, we find that the dark matter particle mass can also be determined from the FSR spectrum.

25 pages, 6 figures. References added, model identification section modified, general conclusions unchanged. Final version accepted for publication in Journal of Cosmology and Astroparticle Physics

References in corpus (54)

• Dwarf Galaxies of the Local Group
• Observation of an anomalous positron abundance in the cosmic radiation
• A Theory of Dark Matter
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• Muon Decay and Physics Beyond the Standard Model
• The energy spectrum of cosmic-ray electrons at TeV energies
• Observability of Gamma Rays from Dark Matter Neutralino Annihilations in the Milky Way Halo
• Non-Perturbative Effect on Dark Matter Annihilation and Gamma Ray Signature from Galactic Center
• Model-independent implications of the e+, e-, anti-proton cosmic ray spectra on properties of Dark Matter
• Pulsars as the Sources of High Energy Cosmic Ray Positrons
• Probing the ATIC peak in the cosmic-ray electron spectrum with H.E.S.S
• CMB Constraints on WIMP Annihilation: Energy Absorption During the Recombination Epoch
• Explosive Dark Matter Annihilation
• VERITAS: the Very Energetic Radiation Imaging Telescope Array System
• TeV Gamma Rays from Geminga and the Origin of the GeV Positron Excess
• CMB constraints on Dark Matter models with large annihilation cross-section
• Maverick dark matter at colliders
• VHE Gamma-Ray Observation of the Crab Nebula and its Pulsar with the MAGIC telescope
• Observations of Milky Way Dwarf Spheroidal galaxies with the Fermi-LAT detector and constraints on Dark Matter models
• Gamma-ray and radio tests of the e+e- excess from DM annihilations
• Dark Matter through the Axion Portal
• The Least Luminous Galaxy: Spectroscopy of the Milky Way Satellite Segue 1
• Dark Matter Interpretations of the Electron/Positron Excesses after FERMI
• Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments
• Dark Matter at Colliders: a Model-Independent Approach
• Can the WIMP annihilation boost factor be boosted by the Sommerfeld enhancement?
• The Dark Matter Annihilation Signal from Galactic Substructure: Predictions for GLAST
• Dark matter interpretation of recent electron and positron data
• The Most Dark Matter Dominated Galaxies: Predicted Gamma-ray Signals from the Faintest Milky Way Dwarfs
• The Case for a 700+ GeV WIMP: Cosmic Ray Spectra from PAMELA, Fermi and ATIC
• Indirect Dark Matter Detection from Dwarf Satellites: Joint Expectations from Astrophysics and Supersymmetry
• Bounds on Cross-sections and Lifetimes for Dark Matter Annihilation and Decay into Charged Leptons from Gamma-ray Observations of Dwarf Galaxies
• Robust implications on Dark Matter from the first FERMI sky gamma map
• Dark Matter Signals from Cascade Annihilations
• Gamma-ray and Radio Constraints of High Positron Rate Dark Matter Models Annihilating into New Light Particles
• The PAMELA Positron Excess from Annihilations into a Light Boson
• Observations of the Sagittarius Dwarf galaxy by the H.E.S.S. experiment and search for a Dark Matter signal
• High Energy Positrons and the WMAP Haze from Exciting Dark Matter
• Discriminating different scenarios to account for the cosmic $e^{\pm }$ excess by synchrotron and inverse Compton radiation
• Direct Constraints on Minimal Supersymmetry from Fermi-LAT Observations of the Dwarf Galaxy Segue 1
• Upper limit for gamma-ray emission above 140 GeV from the dwarf spheroidal galaxy Draco
• Dark Matter Sees The Light
• Dark Matter signals from Draco and Willman 1: Prospects for MAGIC II and CTA
• Upper Limits on the VHE gamma-ray Emission from the Willman 1 Satellite Galaxy with the MAGIC telescope
• Design Study of CANGAROO-III, Stereoscopic Imaging Atmospheric Cherenkov Telescopes for sub-TeV Gamma-ray
• A Search for Dark Matter Annihilation with the Whipple 10m Telescope
• Can multistate dark matter annihilation explain the high-energy cosmic ray lepton anomalies?
• Shedding Light on the Dark Sector with Direct WIMP Production
• Annihilation vs. Decay: Constraining dark matter properties from a gamma-ray detection
• Could the Fermi-LAT detect gamma-rays from dark matter annihilation in the dwarf galaxies of the Local Group?
• Comment on Calculation of Positron Flux from Galactic Dark Matter
• May Heavy neutrinos solve underground and cosmic ray puzzles?
• VERITAS Observations of Extragalactic Non-Blazars

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• Indirect Detection of Dark Matter Using MeV-Range Gamma-Ray Telescopes
• Indirect Detection Analysis: Wino Dark Matter Case Study
• Fitting formulae for photon spectra from WIMP annihilation
• Photon spectra from WIMP annihilation
• Extracting limits on Dark Matter annihilation from gamma-ray observations towards dwarf spheroidal galaxies
• Local Group dSph radio survey with ATCA (III): Constraints on Particle Dark Matter
• Decaying Dark Matter in Supersymmetric Model and Cosmic-Ray Observations
• Prospects of future MeV telescopes in probing weak-scale Dark Matter
• Indirect detection of dark matter absorption in the Galactic Center