New dark matter analysis of milky way dwarf satellite galaxies with madhatv2

Abstract

We obtain bounds on dark matter annihilation using 14 years of publicly available Fermi-LAT data from a set of 54 dwarf spheroidal galaxies, using spectral information from 16 energy bins. We perform this analysis using our updated and publicly available code , which can be used to test a variety of models for dark matter particle physics and astrophysics in an accessible manner. In particular, we note that including Carina III in the analysis strengthens constraints on s-wave annihilation into two-body Standard Model final states by a factor of ∼3 but broadens the error on the constraint due to the large uncertainty of its J-factor. Our findings illustrate the importance of verifying if Carina III is in fact a dwarf spheroidal galaxy and measuring more precisely its J-factor. More generally, they highlight the significance of forthcoming discoveries of nearby ultrafaint dwarfs for dark matter indirect detection. Published by the American Physical Society 2024