Constraining dark matter annihilation with HSC low surface brightness galaxies

Searches for dark matter annihilation signals have been carried out in a number of target regions such as the Galactic Center and Milky Way dwarf spheroidal galaxies (dSphs), among a few others. Here we propose low surface brightness galaxies (LSBGs) as novel targets for the indirect detection of dark matter emission. In particular, LSBGs are known to have very large dark matter contents and be less contaminated by extragalactic γ-ray sources (e.g., blazars) compared to star forming galaxies. We report on an analysis that uses eight LSBGs (detected by Subaru Hyper Suprime-Cam survey data) with known redshifts to conduct a search for γ-ray emission at the positions of these new objects in Fermi Large Area Telescope data. We found no excesses of γ-ray emission and set constraints on the dark matter annihilation cross-section. We exclude (at the 95% C.L.) dark matter scenarios predicting a cross-section higher than ~ 10−23 [cm3/s] for dark matter particles of mass 10 GeV self-annihilating in the b channel. Although this constraint is weaker than the ones reported in recent studies using other targets, we note that in the near future, the number of detections of new LSBGs will increase by a few orders of magnitude. We forecast that with the use of the full catalog of soon-to-be-detected LSBGs the constraint will reach cross-section sensitivities of ~ 3× 10−25 [cm3/s] for dark matter particles with masses 10 GeV.