Year: 2003
Type: article
Abstract: We report EGRET upper limits on the high-energy gamma-ray emission from clusters of galaxies. EGRET observations between 1991 and 2000 were analyzed at positions of 58 individual clusters from a flux-limited sample of nearby X-ray-bright galaxy clusters. Subsequently, a co-added image from individual galaxy clusters has been analyzed using an adequately adapted diffuse gamma-ray foreground model. The resulting upper 2 σ limit for the average cluster is ~6 × 10 -9 cm -2 s -1 for E > 100 MeV. Implications of the nondetection of prominent individual clusters and of the general inability to detect the X-ray-brightest galaxy clusters as a class of gamma-ray emitters are discussed. We compare our results with model predictions on the high-energy gamma-ray emission from galaxy clusters as well as with recent claims of an association between unidentified or unresolved gamma-ray sources and Abell clusters of galaxies and find these contradictory.
Source: The Astrophysical Journal
DOI: 10.1086/374046
Authors: O. Reimer, M. Pohl, P. Sreekumar, J. R. Mattox
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1966600171