$\gamma$-ray flux from Dark Matter Annihilation in Galactic Caustics

Abstract

In the frame of indirect dark matter searches we investigate the flux of high-energy $\gamma$-ray photons produced by annihilation of dark matter in caustics within our Galaxy under the hypothesis that the bulk of dark matter is composed of the lightest supersymmetric particles. Unfortunately, the detection of the caustics annihilation signal with currently available instruments is rather challenging. Indeed, with realistic assumptions concerning particle physics and cosmology, the $\gamma$-ray signal from caustics is below the detection threshold of both $\check{\mathrm{C}}$erenkov telescopes and satellite-borne experiments. Nevertheless, we find that this signal is more prominent than that expected if annihilation only occurs in the smoothed Galactic halo, with the possible exception of a $\sim 15^{\circ }$ circle around the Galactic center if the mass density profile of our Galaxy exhibits a sharp cusp there. We show that the angular distribution of this $\gamma$-ray flux changes significantly if DM annihilation preferentially occurs within virialized sub-halos populating our Galaxy rather than in caustics.

arXiv comment17 pages, 8 figures. Accepted for publication in JCAP

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Cited by in corpus (11)

• Dark Matter Candidates: A Ten-Point Test
• Fitting the Gamma-Ray Spectrum from Dark Matter with DMFIT: GLAST and the Galactic Center Region
• The fine-grained phase-space structure of Cold Dark Matter halos
• The Caustic Ring Model of the Milky Way Halo
• Robustness of Discrete Flows and Caustics in Cold Dark Matter Cosmology
• Does the Second Caustic Ring of Dark Matter Cause the Monoceros Ring of Stars ?
• A further look at particle annihilation in dark matter caustics
• Probing dark matter caustics with weak lensing
• Seen and unseen tidal caustics in the Andromeda galaxy
• WIMP annihilation in caustics
• Testing universal dark-matter caustic rings with galactic rotation curves