Fitting the Fermi-LAT GeV excess: on the importance of the propagation\n of electrons from dark matter

2015/01/29 by Thomas Lacroix, Lacroix, Thomas
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Phenomenology (hep-ph) #Scientific Research and Discoveries

paper · pdf · doi:10.48550/arxiv.1501.07485

openalex publication_date 2015/01/29 · openalex created_date 2022/08/16 · openalex updated_date 2026/07/28

Abstract

An excess of gamma rays at GeV energies has been detected in the Fermi-LAT\ndata. This signal comes from a narrow region around the Galactic Center and has\nbeen interpreted as possible evidence for light (30 GeV) dark matter particles.\nFocussing on the prompt gamma-ray emission, previous works found that the best\nfit to the data corresponds to annihilations proceeding into b quarks, with a\ndark matter profile going as r^-1.2. We show that this is not the only\npossible annihilation set-up. More specifically, we show how including the\ncontributions to the gamma-ray spectrum from inverse Compton scattering and\nbremsstrahlung from electrons produced in dark matter annihilations, and\nundergoing diffusion through the Galactic magnetic field, significantly affects\nthe spectrum for leptonic final states. This drastically changes the\ninterpretation of the excess in terms of dark matter.\n

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