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Title: A tentative gamma-ray line from Dark Matter annihilation at the Fermi Large Area Telescope

Abstract

The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large Area Telescope (LAT), concentrating on energies between 20 and 300 GeV. Besides updating to 43 months of data, we use a new data-driven technique to select optimized target regions depending on the profile of the Galactic dark matter halo. In regions close to the Galactic center, we find a 4.6σ indication for a gamma-ray line at E{sub γ} ≈ 130 GeV. When taking into account the look-elsewhere effect the significance of the observed excess is 3.2σ. If interpreted in terms of dark matter particles annihilating into a photon pair, the observations imply a dark matter mass of m{sub χ} = 129.8±2.4 {sup +7}{sub −13} GeV and a partial annihilation cross-section of (σv){sub χχ} {sub →} {sub γγ} = (1.27±0.32 {sup +0.18}{sub −0.28}) × 10{sup −27}cm{sup 3}s{sup −1} when using the Einasto dark matter profile. The evidence for the signal is based on about 50 photons; it will take a few years of additional data to clarify its existence.

Authors:
 [1]
  1. Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany)
Publication Date:
OSTI Identifier:
22279911
Resource Type:
Journal Article
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2012; Journal Issue: 08; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANNIHILATION; ASTROPHYSICS; COSMIC RAY FLUX; COSMOLOGY; CROSS SECTIONS; GAMMA RADIATION; GEV RANGE; MASS; MILKY WAY; NONLUMINOUS MATTER; PHOTONS; TELESCOPES; UNIVERSE

Citation Formats

Weniger, Christoph. A tentative gamma-ray line from Dark Matter annihilation at the Fermi Large Area Telescope. United States: N. p., 2012. Web. doi:10.1088/1475-7516/2012/08/007.
Weniger, Christoph. A tentative gamma-ray line from Dark Matter annihilation at the Fermi Large Area Telescope. United States. https://doi.org/10.1088/1475-7516/2012/08/007
Weniger, Christoph. Wed . "A tentative gamma-ray line from Dark Matter annihilation at the Fermi Large Area Telescope". United States. https://doi.org/10.1088/1475-7516/2012/08/007.
@article{osti_22279911,
title = {A tentative gamma-ray line from Dark Matter annihilation at the Fermi Large Area Telescope},
author = {Weniger, Christoph},
abstractNote = {The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large Area Telescope (LAT), concentrating on energies between 20 and 300 GeV. Besides updating to 43 months of data, we use a new data-driven technique to select optimized target regions depending on the profile of the Galactic dark matter halo. In regions close to the Galactic center, we find a 4.6σ indication for a gamma-ray line at E{sub γ} ≈ 130 GeV. When taking into account the look-elsewhere effect the significance of the observed excess is 3.2σ. If interpreted in terms of dark matter particles annihilating into a photon pair, the observations imply a dark matter mass of m{sub χ} = 129.8±2.4 {sup +7}{sub −13} GeV and a partial annihilation cross-section of (σv){sub χχ} {sub →} {sub γγ} = (1.27±0.32 {sup +0.18}{sub −0.28}) × 10{sup −27}cm{sup 3}s{sup −1} when using the Einasto dark matter profile. The evidence for the signal is based on about 50 photons; it will take a few years of additional data to clarify its existence.},
doi = {10.1088/1475-7516/2012/08/007},
url = {https://www.osti.gov/biblio/22279911}, journal = {Journal of Cosmology and Astroparticle Physics},
issn = {1475-7516},
number = 08,
volume = 2012,
place = {United States},
year = {2012},
month = {8}
}