Constraints on decaying dark matter from XMM–Newton observations of M31 |
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Authors: | Alexey Boyarsky Dmytro Iakubovskyi Oleg Ruchayskiy Vladimir Savchenko |
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Institution: | PH-TH, CERN, CH-1211 Geneve 23, Switzerland;Bogolyubov Institute for Theoretical Physics, Kiev 03780, Ukraine;École Polytechnique Fédérale de Lausanne, Institute of Theoretical Physics, FSB/ITP/LPPC, BSP 720, CH-1015 Lausanne, Switzerland;Department of Physics, Kiev National Taras Shevchenko University, Kiev 03022, Ukraine |
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Abstract: | We derive constraints on the parameters of the radiatively decaying dark matter (DM) particle, using the XMM–Newton EPIC spectra of the Andromeda galaxy (M31). Using the observations of the outer (5–13 arcmin) parts of M31, we improve the existing constraints. For the case of sterile neutrino DM, combining our constraints with the latest computation of abundances of sterile neutrinos in the Dodelson–Widrow (DW) scenario, we obtain the lower mass limit m s < 4 keV , which is stronger than the previous one m s < 6 keV , obtained recently by Asaka, Laine & Shaposhnikov. Comparing this limit with the most recent results on Lyman α forest analysis of Viel et al. ( m s > 5.6 keV ), we argue that the scenario in which all the DM is produced via the DW mechanism is ruled out. We discuss, however, other production mechanisms and note that the sterile neutrino remains a viable candidate for DM, either warm or cold. |
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Keywords: | methods: data analysis galaxies: individual: Andromeda galaxy dark matter X-rays: individual: Andromeda galaxy |
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