Search for dark matter annihilation signals from unidentified Fermi-LAT objects with H.E.S.S.

Discussion timeslot (ZOOM-Meeting): 20. July 2021 - 12:00
ZOOM-Meeting URL: https://desy.zoom.us/j/96969970711
ZOOM-Meeting ID: 96969970711
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/40-Dark-Matter-Indirect-Detection-and-Cosmological-Substructures-DM/81
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-07/8

Abstract:
'Cosmological N-body simulations show that Milky-Way-sized galaxies harbor a population of unmerged dark matter subhalos. These subhalos could shine in gamma rays and be eventually detected in gamma-ray surveys as unidentified sources. We search for very-high-energy (VHE, E ≥ 100 GeV) gamma-ray emission using H.E.S.S. observations carried out on a thorough selection of unidentified Fermi-LAT Objects (UFOs) as dark matter subhalo candidates. Provided that the dark matter mass is higher than a few hundred GeV, the emission of the UFOs can be well described by dark matter annihilation models. No significant VHE gamma-ray emission is detected in any UFO dataset nor in their combination. We, therefore, derive constraints on the product of the velocity-weighted annihilation cross-section smaller sigma v larger by the J-factor on dark matter models describing the UFO emissions. Upper limits at 95% confidence level (CL) are derived on sigma v J in W+W- and tau+tau- annihilation channels for the TeV dark matter particles. Focusing on thermal WIMPs, strong constraints on the J-factors are obtained from H.E.S.S. observations. Adopting model-dependent predictions from cosmological N-body simulations on the J-factor distribution function for Milky Way-sized galaxies, the dark matter models for the UFO emissions could be ruled out at high confidence level.'

Authors: Alessandro Montanari | Dorit Glawion | Emmanuel Moulin | Denys Malyshev | For the H.E.S.S. collaboration
Collaboration: H.E.S.S.

Indico-ID: 1241
Proceeding URL: https://pos.sissa.it/395/538