NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Searching for the 3.5 keV Line in the Stacked Suzaku Observations of Galaxy ClustersWe perform a detailed study of the stacked Suzaku observations of 47 galaxy clusters, spanning a redshift range of 0.01-0.45, to search for the unidentified 3.5 keV line. This sample provides an independent test for the previously detected line. We detect a 2sigma-significant spectral feature at 3.5 keV in the spectrum of the full sample. When the sample is divided into two subsamples (cool-core and non-cool core clusters), the cool-core subsample shows no statistically significant positive residuals at the line energy. A very weak (approx. 2sigma confidence) spectral feature at 3.5 keV is permitted by the data from the non-cool-core clusters sample. The upper limit on a neutrino decay mixing angle of sin(sup 2)(2theta) = 6.1 x 10(exp -11) from the full Suzaku sample is consistent with the previous detections in the stacked XMM-Newton sample of galaxy clusters (which had a higher statistical sensitivity to faint lines), M31, and Galactic center, at a 90% confidence level. However, the constraint from the present sample, which does not include the Perseus cluster, is in tension with previously reported line flux observed in the core of the Perseus cluster with XMM-Newton and Suzaku.
Document ID
20170003457
Document Type
Reprint (Version printed in journal)
Authors
Bulbul, Esra (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Markevitch, Maxim (NASA Goddard Space Flight Center Greenbelt, MD United States)
Foster, Adam (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Miller, Eric (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Bautz, Mark (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Lowenstein, Mike (NASA Goddard Space Flight Center Greenbelt, MD United States)
Randall, Scott W. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Smith, Randall K. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Date Acquired
April 14, 2017
Publication Date
October 26, 2016
Publication Information
Publication: The Astrophysical Journal
Volume: 831
Issue: 1
ISSN: 0004-637X
Subject Category
Astrophysics
Report/Patent Number
GSFC-E-DAA-TN41271
Funding Number(s)
CONTRACT_GRANT: NNX15AC76G
CONTRACT_GRANT: NNX15AE16G
CONTRACT_GRANT: NAS8-03060
CONTRACT_GRANT: NNX13AE77G
CONTRACT_GRANT: NNX14AF78G
Distribution Limits
Public
Copyright
Other
Keywords
dark matter