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Title: Probing dark matter decay and annihilation with Fermi LAT observations of nearby galaxy clusters

Abstract

Galaxy clusters are promising targets for indirect dark matter searches. Gamma-ray signatures from the decay or annihilation of dark matter particles inside these clusters could be observable with the Fermi Large Area Telescope (LAT). Based on three years of Fermi LAT gamma-ray data, we analyze the flux coming from eight nearby clusters individually as well as in a combined likelihood analysis. Concentrating mostly on signals from dark matter decay, we take into account uncertainties of the cluster masses as determined by X-ray observations and model the cluster emission as extended sources. Searching for different hadronic and leptonic decay and annihilation spectra, we do not find significant emission from any of the considered clusters and present limits on the dark matter lifetime and annihilation cross-section. We compare our lifetime limits derived from cluster observations with the limits that can be obtained from the extragalactic gamma-ray background (EGBG), and find that in case of hadronic decay the cluster limits become competitive at dark matter masses below a few hundred GeV. In case of leptonic decay, however, galaxy cluster limits are stronger than the limits from the EGBG over the full considered mass range. Finally, we show that in presence of dark mattermore » substructures down to 10{sup −6} solar masses the limits on the dark matter annihilation cross-section could improve by a factor of a few hundred, possibly going down to the thermal cross-section of 3 × 10{sup −26}cm{sup 3}s{sup −1} for dark matter masses ∼<150GeV and annihilation into b b-bar . As a direct application of our results, we derive limits on the lifetime of gravitino dark matter in scenarios with R-parity violation. Implications of these limits for the possible observation of long-lived superparticles at the LHC are discussed.« less

Authors:
 [1];  [2];  [3]
  1. National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China)
  2. Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22603 Hamburg (Germany)
  3. Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany)
Publication Date:
OSTI Identifier:
22279733
Resource Type:
Journal Article
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2012; Journal Issue: 01; 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; CERN LHC; COMPARATIVE EVALUATIONS; COSMOLOGY; CROSS SECTIONS; GALAXY CLUSTERS; GAMMA RADIATION; GAMMA SPECTRA; GEV RANGE; GRAVITONS; HADRONIC PARTICLE DECAY; LEPTONIC DECAY; LIFETIME; MASS; NONLUMINOUS MATTER; SPARTICLES; X RADIATION

Citation Formats

Huang, Xiaoyuan, Vertongen, Gilles, and Weniger, Christoph. Probing dark matter decay and annihilation with Fermi LAT observations of nearby galaxy clusters. United States: N. p., 2012. Web. doi:10.1088/1475-7516/2012/01/042.
Huang, Xiaoyuan, Vertongen, Gilles, & Weniger, Christoph. Probing dark matter decay and annihilation with Fermi LAT observations of nearby galaxy clusters. United States. https://doi.org/10.1088/1475-7516/2012/01/042
Huang, Xiaoyuan, Vertongen, Gilles, and Weniger, Christoph. 2012. "Probing dark matter decay and annihilation with Fermi LAT observations of nearby galaxy clusters". United States. https://doi.org/10.1088/1475-7516/2012/01/042.
@article{osti_22279733,
title = {Probing dark matter decay and annihilation with Fermi LAT observations of nearby galaxy clusters},
author = {Huang, Xiaoyuan and Vertongen, Gilles and Weniger, Christoph},
abstractNote = {Galaxy clusters are promising targets for indirect dark matter searches. Gamma-ray signatures from the decay or annihilation of dark matter particles inside these clusters could be observable with the Fermi Large Area Telescope (LAT). Based on three years of Fermi LAT gamma-ray data, we analyze the flux coming from eight nearby clusters individually as well as in a combined likelihood analysis. Concentrating mostly on signals from dark matter decay, we take into account uncertainties of the cluster masses as determined by X-ray observations and model the cluster emission as extended sources. Searching for different hadronic and leptonic decay and annihilation spectra, we do not find significant emission from any of the considered clusters and present limits on the dark matter lifetime and annihilation cross-section. We compare our lifetime limits derived from cluster observations with the limits that can be obtained from the extragalactic gamma-ray background (EGBG), and find that in case of hadronic decay the cluster limits become competitive at dark matter masses below a few hundred GeV. In case of leptonic decay, however, galaxy cluster limits are stronger than the limits from the EGBG over the full considered mass range. Finally, we show that in presence of dark matter substructures down to 10{sup −6} solar masses the limits on the dark matter annihilation cross-section could improve by a factor of a few hundred, possibly going down to the thermal cross-section of 3 × 10{sup −26}cm{sup 3}s{sup −1} for dark matter masses ∼<150GeV and annihilation into b b-bar . As a direct application of our results, we derive limits on the lifetime of gravitino dark matter in scenarios with R-parity violation. Implications of these limits for the possible observation of long-lived superparticles at the LHC are discussed.},
doi = {10.1088/1475-7516/2012/01/042},
url = {https://www.osti.gov/biblio/22279733}, journal = {Journal of Cosmology and Astroparticle Physics},
issn = {1475-7516},
number = 01,
volume = 2012,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2012},
month = {Sun Jan 01 00:00:00 EST 2012}
}