NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
The Swift BAT Perspective on Non-Thermal Emission in HIFLUGCS Galaxy ClustersThe search for diffuse non-thermal, inverse Compton (IC) emission from galaxy clusters at hard X-ray energies has been underway for many years, with most detections being either of low significance or controversial. Until recently, comprehensive surveys of hard X-ray emission from clusters were not possible; instead, individually proposed-for. long observations would be collated from the archive. With the advent of the Swift BAT all sky survey, any c1u,;ter's emission above 14 keV can be probed with nearly uniform sensitivity. which is comparable to that of RXTE, Beppo-SAX, and Suzaku with the 58-month version of the survey. In this work. we search for non-thermal excess emission above the exponentially decreasing, high energy thermal emission in the flux-limited HIFLUGCS sample. The BAT emission from many of the detected clusters is marginally extended; we are able to extract the total flux for these clusters using fiducial models for their spatial extent. To account for thermal emission at BAT energies, XMM-Newton EPIC spectra are extracted from coincident spatial regions so that both the thermal and non-thermal spectral components can be determined simultaneou,;ly in joint fits. We find marginally significant IC components in 6 clusters, though after closer inspection and consideration of systematic errors we are unable to claim a clear detection in any of them. The spectra of all clusters are also summed to enhance a cumulative non-thermal signal not quite detectable in individual clusters. After constructing a model based on single temperature
Document ID
20110010267
Acquisition Source
Goddard Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Wik, Daniel R.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 25, 2013
Publication Date
January 1, 2011
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: BMBF 50 OR 1005
CONTRACT_GRANT: NNX08AW83G
CONTRACT_GRANT: NNX09AH25G
CONTRACT_GRANT: NNX09AH74G
CONTRACT_GRANT: NNH06CC03B
CONTRACT_GRANT: NNX08AZ34G
CONTRACT_GRANT: NNX08AZ99G
Distribution Limits
Public
Copyright
Public Use Permitted.
No Preview Available