Table of Contents
Physics Research International
Volume 2016, Article ID 2394965, 4 pages
Research Article

Observational Constraints of 30–40 GeV Dark Matter Annihilation in Galaxy Clusters

The Hong Kong Institute of Education, Tai Po, Hong Kong

Received 5 October 2015; Accepted 6 January 2016

Academic Editor: W. Niel Brandt

Copyright © 2016 Man Ho Chan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Recently, it has been shown that the annihilation of 30–40 GeV dark matter particles through channel can satisfactorily explain the excess GeV gamma-ray spectrum near the Galactic Center. In this paper, we apply the above model to galaxy clusters and use the latest upper limits of gamma-ray flux derived from Fermi-LAT data to obtain an upper bound of the annihilation cross section of dark matter. By considering the extended density profiles and the cosmic ray profile models of 49 galaxy clusters, the upper bound of the annihilation cross section can be further tightened to  cm3 s−1. This result is consistent with the one obtained from the data near the Galactic Center.