Mapping the dark trajectory of the Bullet Cluster

TL;DR

This paper models dark matter annihilation-produced electrons and positrons in the Bullet Cluster, showing their potential for detection via the SZ effect, especially considering substructure enhancements.

Contribution

It introduces a detailed model of charged particle trajectories from dark matter annihilation in a colliding galaxy cluster, highlighting the impact of subhalos on detection prospects.

Findings

Dark matter annihilation produces detectable electrons and positrons in the Bullet Cluster.

Substructure significantly enhances the annihilation rate and positron density.

Potential for unambiguous detection of dark matter signals via the SZ effect.

Abstract

We model the electrons/positrons produced by dark matter annihilations in the colliding galaxy cluster system 1E0657-56 (the bullet cluster). These charged particles, confined by the Magnetic field, clearly trace the path of the bullet, which passes through the main cluster with a speed of 3000-5000 km/s. Adding the effect of dark matter substructure (subhalos) in each cluster we find the annihilation rate is enhancedgreatly and the density of positrons in the trail is similar to that within the bullet cluster. This opens the door to unambiguous detection of the annihilation signal through the SZ effect, at significant separation from the thermal electrons.