Constraints on dark matter annihilation in clusters of galaxies with the Fermi large area telescope
2010 (English)In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, no 5, 025- p.Article in journal (Refereed) Published
Nearby clusters and groups of galaxies are potentially bright sources of highenergy gamma-ray emission resulting from the pair-annihilation of dark matter particles. However, no significant gamma-ray emission has been detected so far from clusters in the first 11 months of observations with the Fermi Large Area Telescope. We interpret this non-detection in terms of constraints on dark matter particle properties. In particular for leptonic annihilation final states and particle masses greater than similar to 200GeV, gamma-ray emission from inverse Compton scattering of CMB photons is expected to dominate the dark matter annihilation signal from clusters, and our gamma-ray limits exclude large regions of the parameter space that would give a good fit to the recent anomalous Pamela and Fermi-LAT electron-positron measurements. We also present constraints on the annihilation of more standard dark matter candidates, such as the lightest neutralino of supersymmetric models. The constraints are particularly strong when including the fact that clusters are known to contain substructure at least on galaxy scales, increasing the expected gammaray flux by a factor of similar to 5 over a smooth-halo assumption. We also explore the effect of uncertainties in cluster dark matter density profiles, finding a systematic uncertainty in the constraints of roughly a factor of two, but similar overall conclusions. In this work, we focus on deriving limits on dark matter models; a more general consideration of the Fermi-LAT data on clusters and clusters as gamma-ray sources is forthcoming.
Place, publisher, year, edition, pages
2010. no 5, 025- p.
gamma ray experiments, galaxy clusters, supersymmetry and cosmology, dark energy theory
IdentifiersURN: urn:nbn:se:kth:diva-27241DOI: 10.1088/1475-7516/2010/05/025ISI: 000279490800015ScopusID: 2-s2.0-77952986099OAI: oai:DiVA.org:kth-27241DiVA: diva2:382654
QC 201101032011-01-032010-12-092011-01-03Bibliographically approved