Prospects for Indirect Dark Matter Searches with the Cherenkov Telescope Array (CTA)

TL;DR

This paper discusses the potential of the Cherenkov Telescope Array (CTA) to detect dark matter through indirect searches, focusing on strategies, target regions, and sensitivity predictions for various astrophysical objects.

Contribution

It provides detailed sensitivity estimates and observational strategies for dark matter detection with CTA, considering different targets and uncertainties.

Findings

CTA can probe dark matter annihilation cross-sections below the thermal relic level.

Observations of the Galactic Centre and dwarf galaxies offer promising detection prospects.

Sensitivity predictions account for instrument response and background uncertainties.

Abstract

The Cherenkov Telescope Array (CTA) will have a unique chance of discovery for a large range of masses in Weakly Interacting Massive Particles models of dark matter. The principal target for dark matter searches with CTA is the centre of the Galactic Halo. The best strategy is to perform CTA observations within a few degrees of the Galactic Centre, with the Galactic Centre itself and the most intense diffuse emission regions removed from the analysis. Assuming a cuspy dark matter density profile for the Milky Way, 500 hours of observations in this region provide sensitivities to and below the thermal cross-section of dark matter annihilations, for masses between a few hundred GeV and a few tens of TeV; therefore CTA will have a significant chance of discovery in some models. Since the dark matter density in the Milky Way is far from certain in the inner kpc region, other targets are also proposed for observation, like ultra-faint dwarf galaxies such as Segue 1 with 100 hours per year proposed. Beyond these two observational targets, further alternatives, such as Galactic dark clumps, will be considered closer to the actual date of CTA operations. Sensitivity predictions for dark matter searches are given on the various targets taking into account the latest instrument response functions expected for CTA together with a discussion on the systematic uncertainties from the backgrounds.