Towards a Bullet-proof test for indirect signals of dark matter

Understand

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.