Title:	Intracluster gas pressure, entropy injection and redshift evolution
Authors:	Nath, Biman B. Majumdar, S.
Keywords:	galaxies: clusters: general X-rays: galaxies: clusters cosmology: miscellaneous intergalactic medium
Issue Date:	Sep-2011
Publisher:	Wiley Interscience for the RAS
Citation:	Monthly Notices of the Royal Astronomical Society, 2011, Vol.416, p279 pNA
Abstract:	We study the effect of entropy injection in the intracluster medium (ICM) in light of the recent observationally determined universal pressure profile of the ICM. Beginning with a power-law entropy profile that is expected in the absence of any feedback, we show that a simple universal prescription of entropy injection results in the final, observed universal pressure profile. This simple prescription has two components, one associated with an overall increase in entropy and another associated with injection in the central parts of the cluster. Importantly, both the components of entropy injection are needed to produce the final universal pressure profile. This is indicative of a need of both preheating the ICM as well in situ AGN/SNe heating. We demonstrate the usefulness of the method by extending the calculations to clusters at high redshift, and predict redshift evolution of cluster scaling relations that can be tested against data. We show that the self-similar evolution of the universal pressure profile is equivalent to a negative evolution of entropy injection with redshift, with a scaling Sinj / (1 + z)−0.8Sinj (z = 0). We also show the current observational data is indicative of the entropy injection decreasing with redshift.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/4156
ISSN:	0035-8711 1365-2966 (online)
Alternative Location:	http://adsabs.harvard.edu/abs/2011MNRAS.416..279N http://arxiv.org/abs/1105.2826 http://dx.doi.org/10.1111/j.1365-2966.2011.19033.x
Copyright:	2011 The Authors Monthly Notices of the 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.