Title:	Entropy of the intracluster medium at high redshift
Authors:	Nath, Biman B.
Keywords:	galaxies: clusters: general intergalactic medium cosmology: theory X-rays: galaxies: clusters
Issue Date:	Sep-2004
Publisher:	Blackwell Publishing for the Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2004, Vol.353, Issue 3, p941-946.
Abstract:	Recent observations of the entropy of the intracluster medium (ICM) at high redshift are not consistent with a redshift-independent entropy floor. To interpret these observations, we study models in which the entropy of ICM is enhanced at the epoch of cluster formation (zf), which then passively evolves as a result of radiative cooling until the epoch of observation (zo). We confirm that a z-independent entropy floor is incompatible with the observations. We find that models in which energy deposition into the ICM increases with redshift [scaling approximately as ~M0.6cl(1 +zf)2.2] are consistent with observations of low- and high-redshift clusters. Possible sources of such non-gravitational heating are briefly discussed.
Description:	Restricted Access. An open access version is available at arXiv.org
URI:	http://hdl.handle.net/2289/1514
ISSN:	0035-8711
Alternative Location:	http://arxiv.org/abs/astro-ph/0406451 http://dx.doi.org/10.1111/j.1365-2966.2004.08124.x
Copyright:	(2004) Royal Astronomical Society
Appears in Collections:	Research Papers (A&A)

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.