Detection prospects for heavy WIMP dark matter near supermassive black holes, particularly in M31

TL;DR

This paper evaluates the potential for detecting heavy WIMP dark matter near supermassive black holes, especially in M31, using gamma-ray observations with CTA, highlighting M31* as a promising target for future searches.

Contribution

It identifies M31* as a promising target for heavy WIMP detection and estimates CTA's sensitivity, exploring systematic uncertainties and different spike density scenarios.

Findings

CTA can probe a significant part of TeV-scale WIMP parameter space in M31*.

M31* may provide stronger constraints than MW* under certain conditions.

Detection prospects depend on spike density configurations and systematic uncertainties.

Abstract

This work analyzes the detection prospects for weakly interacting massive particles (WIMPs) in dark matter (DM) density spikes around nearby supermassive black holes (SMBHs) by observations in very high energy gamma-ray band. Such spikes are unique targets, which provide a possibility to discover the basic thermal s-wave annihilating WIMP with any mass up to the theoretical unitarity limit ~ 100 TeV. All relevant SMBHs were checked, and only MW* and M31* were identified as worthwhile objects. Cherenkov Telescope Array (CTA) sensitivity to heavy WIMPs in M31* was estimated. It was obtained that CTA will be able to probe a major part of TeV-scale WIMP parameter space in case of optimistic spike density configuration in M31*. In certain scenarios, M31* may yield even stronger constraints than MW*. Relevant systematic uncertainties were explored.