Abstract
Merging galaxy clusters such as the Bullet Cluster provide a powerful testing ground for indirect detection of dark matter. The spatial distribution of the dark matter is both directly measurable through gravitational lensing and substantially different from the distribution of potential astrophysical backgrounds. We propose to use this spatial information to identify the origin of indirect detection signals, and we show that even statistical excesses of a few sigma can be robustly tested for consistency—or inconsistency—with a dark matter source. For example, our methods, combined with already-existing observations of the Coma Cluster, would allow the 3.55 keV line to be tested for compatibility with a dark matter origin. We also discuss the optimal spatial reweighting of photons for indirect detection searches. The current discovery rate of merging galaxy clusters and associated lensing maps strongly motivates deep exposures in these dark matter targets for both current and upcoming indirect detection experiments in the x-ray and gamma-ray bands.
- Received 13 March 2015
DOI:https://doi.org/10.1103/PhysRevD.91.103524
© 2015 American Physical Society
Synopsis
Spatial Tests of Dark Matter
Published 20 May 2015
Maps of merging galaxy clusters could help find signatures of dark matter based on its decay into photons.
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