Galaxy cluster outskirts: a universal entropy profile for relaxed clusters?
Article first published online: 25 SEP 2012
© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS
Monthly Notices of the Royal Astronomical Society: Letters
Volume 427, Issue 1, pages L45–L49, November 2012
How to Cite
Walker, S. A., Fabian, A. C., Sanders, J. S. and George, M. R. (2012), Galaxy cluster outskirts: a universal entropy profile for relaxed clusters?. Monthly Notices of the Royal Astronomical Society: Letters, 427: L45–L49. doi: 10.1111/j.1745-3933.2012.01342.x
- Issue published online: 7 NOV 2012
- Article first published online: 25 SEP 2012
- Accepted 2012 August 28. Received 2012 August 27; in original form 2012 August 9
- galaxies: clusters: general;
- X-rays: galaxies: clusters
We fit a functional form for a universal intracluster medium entropy profile to the scaled entropy profiles of a catalogue of X-ray galaxy cluster outskirts results, which are all relaxed cool core clusters at redshift below 0.25. We also investigate the functional form suggested by Lapi et al. and Cavaliere et al. for the behaviour of the entropy profile in the outskirts and find it to fit the data well outside 0.3r200. We highlight the discrepancy in the entropy profile behaviour in the outskirts between observations and the numerical simulations of Burns et al., and show that the entropy profile flattening due to gas clumping calculated by Nagai & Lau is insufficient to match observations, suggesting that gas clumping alone cannot be responsible for all of the entropy profile flattening in the cluster outskirts. The entropy profiles found with Suzaku are found to be consistent with ROSAT, XMM–Newton and Planck results.