The XMM Cluster Survey: new evidence for the 3.5-keV feature in clusters is inconsistent with a dark matter origin

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Bhargava, S (Author) Other; Giles, PA (Author) Other; Romer, AK (Author) Other; Jeltema, T (Author) Other; Mayers, J (Author) Other; Bermeo, A (Author) Other; Hilton, M (Author) Other; Wilkinson, R (Author) Other; Vergara, C (Author) Other; Collins, CA (Author) Other; Manolopoulou, M (Author) Other; Rooney, PJ (Author) Other; Rosborough, S (Author) Other; Sabirli, K (Author) Other; Stott, JP (Author) Other; Swann, E (Author) Other; viana, ptp (Author) FCUP

Journal

Title: Monthly Notices of the Royal Astronomical Society

Vol. 497

Pages: 656-671

ISSN: 0035-8711

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 16 Citations

Other information

Authenticus ID: P-00S-V7T

DOI: 10.1093/mnras/staa1829

Abstract (EN): There have been several reports of a detection of an unexplained excess of X-ray emission at similar or equal to 3.5 keV in astrophysical systems. One interpretation of this excess is the decay of sterile neutrino dark matter. The most influential study to date analysed 73 clusters observed by the XMM-Newton satellite. We explore evidence for a similar or equal to 3.5-keV excess in the XMM-PN spectra of 117 redMaPPer galaxy clusters (0.1 < z < 0.6). In our analysis of individual spectra, we identify three systems with an excess of flux at similar or equal to 3.5 keV. In one case (XCS J0003.3+0204), this excess may result from a discrete emission line. None of these systems are the most dark matter dominated in our sample. We group the remaining 114 clusters into four temperature (T-X) bins to search for an increase in similar or equal to 3.5-keV flux excess with TX - a reliable tracer of halo mass. However, we do not find evidence of a significant excess in flux at similar or equal to 3.5 keV in any TX bins. To maximize sensitivity to a potentially weak dark matter decay feature at similar or equal to 3.5 keV, we jointly fit 114 clusters. Again, no significant excess is found at similar or equal to 3.5 keV. We estimate the upper limit of an undetected emission line at similar or equal to 3.5 keV to be 2.41 x 10(-6) photons cm(-2) s(-1), corresponding to a mixing angle of sin(2)(2 theta) = 4.4 x 10(-11), lower than previous estimates from cluster studies. We conclude that a flux excess at similar or equal to 3.5 keV is not a ubiquitous feature in clusters and therefore unlikely to originate from sterile neutrino dark matter decay.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 16