An indirect search for dark matter with a combined analysis of dwarf spheroidal galaxies from VERITAS

TL;DR

This paper reports a comprehensive search for dark matter signals in gamma rays from dwarf spheroidal galaxies using VERITAS data, setting upper limits on dark matter annihilation cross sections across a wide mass range.

Contribution

It presents the first combined analysis of multiple dwarf spheroidal galaxies with 638 hours of VERITAS data, extending dark matter mass sensitivity from 200 GeV to 30 PeV.

Findings

No gamma-ray signals detected from dSphs.

Established upper limits on dark matter annihilation cross sections.

Extended mass range sensitivity up to 30 PeV.

Abstract

Understanding the nature and identity of dark matter is a key goal in the physics community. In the case that TeV-scale dark matter particles decay or annihilate into standard model particles, very-high-energy (VHE) gamma rays (greater than 100 GeV) will be present in the final state. The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is an imaging atmospheric Cherenkov telescope array that can indirectly detect VHE gamma rays in an energy range of 100 GeV to > 30 TeV. Dwarf spheroidal galaxies (dSphs) are ideal candidates in the search for dark matter due to their high dark matter content, high mass-to-light ratios, and their low gamma-ray fluxes from astrophysical processes. This study uses a legacy data set of 638 hours collected on 17 dSphs, built over 11 years with an observing strategy optimized according to the dark matter content of the targets. The study addresses a broad dark matter particle mass range, extending from 200 GeV to 30 PeV. In the absence of a detection, we set the upper limits on the dark matter velocity-weighted annihilation cross section.