Dark Matter searches in Dwarf Galaxies with the Southern Wide-field Gamma-ray Observatory

TL;DR

This paper predicts the potential of the Southern Wide-field Gamma-ray Observatory (SWGO) to detect or constrain dark matter signals from dwarf galaxies, enhancing indirect detection efforts for WIMPs in the GeV to PeV mass range.

Contribution

It introduces a method to evaluate SWGO's capability to detect dark matter annihilation signals from dwarf galaxies, providing new prospects for indirect dark matter searches.

Findings

SWGO can set competitive limits on dark matter in the 100 GeV to PeV range.

Dwarf galaxies are effective targets for dark matter indirect detection.

Combined observations will improve constraints on dark matter properties.

Abstract

Dark matter is thought to make up most of the matter density of the Universe, yet its true nature remains uncertain. Among dark matter theories, Weakly Interacting Massive Particles (WIMPs) are a prominent candidate for dark matter because they can reproduce the observed abundance of dark matter in the universe. There are various methods for searching for WIMPs, one of which is indirect detection, which involves looking for the Standard Model particles produced by the decay or self-annihilation of dark matter particles. Within the mass range of GeV to PeV for the dark matter particle, this type of search can be conducted by detecting $\gamma$-rays in astrophysical objects with high concentrations of dark matter. Dwarf galaxies, although not the most dense, are excellent targets for this type of observation since they are dominated by dark matter, are relatively close to Earth, and have a low astrophysical background. In this work, the detectability of dark matter annihilation or decay signals from dwarf galaxies is predicted using the Southern Wide-field Gamma-ray Observatory (SWGO), a future $\gamma$-ray observatory that will be built in South America. This wide field-of-view survey instrument will be able to study many important dark matter targets in the Southern Hemisphere, and the combined observation of all targets will provide competitive, if not the best, limits for dark matter with masses in the range of hundreds of GeV to PeV.