Search for dark matter annihilation signatures in H.E.S.S. observations of Dwarf Spheroidal Galaxies

Abstract

Dwarf spheroidal galaxies of the Local Group are close satellites of the Milky Way characterized by a large mass-to-light ratio and are not expected to be the site of non-thermal high-energy gamma-ray emission or intense star formation. Therefore they are amongst the most promising candidates for indirect dark matter searches. During the last years the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric Cherenkov telescopes observed five of these dwarf galaxies for more than 140 hours in total, searching for TeV gamma-ray emission from annihilation of dark matter particles. The new results of the deep exposure of the Sagittarius dwarf spheroidal galaxy, the first observations of the Coma Berenices and Fornax dwarves and the re-analysis of two more dwarf spheroidal galaxies already published by the H.E.S.S. Collaboration, Carina and Sculptor, are presented. In the absence of a significant signal new constraints on the annihilation cross-section applicable to Weakly Interacting Massive Particles (WIMPs) are derived by combining the observations of the five dwarf galaxies. The combined exclusion limit depends on the WIMP mass and the best constraint is reached at 1-2 TeV masses with a cross-section upper bound of ~3.9x10-24 cm^3 s-1 at a 95% confidence level.

to be published in Physical Review D journal; Contact authors: E. Birsin, C. Farnier, G. Lamanna

References in corpus (18)

• PYTHIA 6.4 Physics and Manual
• Observation of an anomalous positron abundance in the cosmic radiation
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• Observations of the Crab Nebula with H.E.S.S
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• The Observed properties of Dark Matter on small spatial scales
• Background Modelling in Very-High-Energy gamma-ray Astronomy
• Weak Corrections are Relevant for Dark Matter Indirect Detection
• The kinematic status and mass content of the Sculptor dwarf spheroidal galaxy
• Does the Fornax dwarf spheroidal have a central cusp or core?
• Exploring Halo Substructure with Giant Stars XI: The Tidal Tails of the Carina Dwarf Spheroidal and the Discovery of Magellanic Cloud Stars in the Carina Foreground
• The Most Dark Matter Dominated Galaxies: Predicted Gamma-ray Signals from the Faintest Milky Way Dwarfs
• Detecting dark matter WIMPs in the Draco dwarf: a multi-wavelength perspective
• Bounds on Cross-sections and Lifetimes for Dark Matter Annihilation and Decay into Charged Leptons from Gamma-ray Observations of Dwarf Galaxies
• H.E.S.S. constraints on Dark Matter annihilations towards the Sculptor and Carina Dwarf Galaxies
• Fitting formulae for photon spectra from WIMP annihilation
• Photon spectra from WIMP annihilation
• The Alpha-element knee of the Sagittarius Stream

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• Dependence of accessible dark matter annihilation cross-sections on the density profiles of dwarf spheroidal galaxies with the Cherenkov Telescope Array
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• Gamma rays from dark matter spikes in EAGLE simulations
• Background rejection using image residuals from large telescopes in imaging atmospheric Cherenkov telescope arrays
• Combined dark matter search towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS
• Prospects for probing dark matter particles and primordial black holes with the Hongmeng mission using the 21 cm global spectrum at cosmic dawn
• Dark Matter and Fundamental Physics Searches with IACTs
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