Gamma Rays from Superheavy Relic Particles in the Halo

Abstract

Superheavy (SH) quasistable particles generated in the Early Universe could be responsable for Ultra High Energy Cosmic Rays (UHECR) and be a component of Cold Dark Matter (CDM) in the universe. These particles are likely to cluster in the galactic halo, so that the main part of UHECR are gamma rays produced in the decay of neutral pions. Charged pions are also produced in the same process and result in high energy electrons. We consider here the production of gamma rays by synchrotron emission of these electrons in the galactic magnetic field. The gamma ray fluxes are in the region of interest for some current and proposed experiments (e.g. EGRET, GLAST, MILAGRO) in the energy range $0.1-10^4$ GeV. A comparison with the existing upper limits at $10^5-10^8$ GeV is also carried out. The detection of this flux of gamma rays would be an important signature of SH relic particles as sources of UHECR and would give a clue to the physics of the Early Universe.

version accepted for publication in Phys. Rev. D

References in corpus (11)

• EGRET Observations of the Extragalactic Gamma Ray Emission
• Extension of the Cosmic-Ray Energy Spectrum Beyond the Predicted Greisen-Zatsepin-Kuz'min Cutoff
• Ultra-high energy cosmic rays without GZK cutoff
• Nonthermal Supermassive Dark Matter
• Cosmological Magnetic Fields Limits in an Inhomogeneous Universe
• Extremely high energy cosmic rays from relic particle decays
• Signatures of Topological Defects
• Evidence for a Galactic gamma ray halo
• Galactic Anisotropy as Signature of ``Top-Down'' Mechanisms of Ultra-High Energy Cosmic Rays
• Limiting SUSY-QCD spectrum and its application for decays of superheavy particles
• Anisotropy of Ultra High Energy Cosmic Rays in the Dark Matter Halo Model

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• Ultra High Energy Cosmic Rays
• High Energy Neutrinos From Superheavy Dark Matter Annihilation
• Halo Dark Matter and Ultra-High Energy Cosmic Rays
• Ionization history of the Universe as a test for Super Heavy Dark Matter particles
• Clustering in Highest Energy Cosmic Rays: Physics or Statistics?
• Quintessence dissipative superattractor cosmology
• Ultra-High Energy Cosmic Rays and Diffuse Photon Spectrum
• Generation of 10^15 - 10^17 eV photons by UHE CR in the Galactic magnetic filed
• Theory of synchrotron radiation: II. Backreaction in ensembles of particles