Report on 2004.06601v1

Abstract

An unidentified line at energy around 3.5 keV was detected in the spectra of dark matter-dominated objects.Recent work (1) used 30 Msec of XMM-Newton blank-sky observations to constrain the admissible line flux, challenging its dark matter decay origin.We demonstrate that these bounds are overestimated by more than an order of magnitude due to improper background modeling.Therefore the dark matter interpretation of the 3.5 keV signal remains viable.An X-ray line at E 3.5 keV has been found in 2014 (2, 3).Many consistency checks, as well as follow-up detections, have been reported, while non-detections have not ruled out the dark matter interpretation of the signal (see (4) for review).Ref. (1) (DRS20 in what follows) recently reported bounds on the decay lifetime, which are about an order of magnitude below

Authors 4

1. Alexey Boyarsky corresponding Aachen Lorentz Institute

   Leiden University

   Affiliation as printed

   Lorentz Institute , Leiden University , Niels Bohrweg 2 , Leiden , NL-2333 CA , The Netherlands

2. Denys Malyshev

   University of Tübingen

   Affiliation as printed

   Institut für Astronomie und Astrophysik Tübingen , Universität Tübingen , Sand 1 , D-72076 Tübingen , Germany

3. Oleg Ruchayskiy

   University of Copenhagen

   Affiliation as printed

   Niels Bohr Institute , Copenhagen University , Blegdamsvej 17 , Copenhagen , DK-2100 , Denmark

4. Denys Savchenko

   Bogolyubov Institute for Theoretical Physics

   Affiliation as printed

   Bogolyubov Institute for Theoretical Physics , Metrolohichna Str. 14-b , 03143 , Kyiv , Ukraine