Search for Galactic dark matter substructures with Cherenkov telescopes

TL;DR

This paper evaluates the potential of current and future Cherenkov telescopes to detect dark matter subhalos in the Milky Way through gamma-ray signals, concluding they are likely too faint for detection.

Contribution

It provides a detailed analysis of the gamma-ray signals from dark matter subhalos using N-body simulations and explores systematic uncertainties in the modeling of dark matter density distributions.

Findings

Galactic dark matter subhalos are probably too faint for detection with Cherenkov telescopes.

Systematic uncertainties significantly affect the predicted gamma-ray signals.

Even with the Cherenkov Telescope Array, detection prospects remain limited.

Abstract

Weakly interacting massive dark matter (DM) particles are expected to self-annihilate or decay, generating high-energy photons in these processes. This establishes the possibility for indirect detection of DM by \gamma-ray telescopes. For probing the secondary products of DM, accurate knowledge about the DM density distribution in potential astrophysical targets is crucial. In this contribution, the prospects for the detection of subhalos in the Galactic DM halo with present and future imaging atmospheric Cherenkov telescopes (IACT) are investigated. The source count distribution and angular power spectra for \gamma-rays originating from annihilating DM in subhalos are calculated from N-body simulation results. To study the systematic uncertainties coming from the modeling of the DM density distribution, parameters describing the \gamma-ray yield from subhalos are varied in 16 benchmark models. We conclude that Galactic subhalos of annihilating DM are probably too faint to be a promising target for IACT observations, even with the prospective Cherenkov Telescope Array (CTA).