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A New Robust Low-Scatter X-Ray Mass Indicator for Clusters of Galaxies

Kravtsov, Andrey V. and Vikhlinin, Alexey and Nagai, Daisuke (2006) A New Robust Low-Scatter X-Ray Mass Indicator for Clusters of Galaxies. Astrophysical Journal, 650 (1). pp. 128-136. ISSN 0004-637X. doi:10.1086/506319.

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We present a comparison of X-ray proxies for the total cluster mass, M_(500), including the spectral temperature (T_X), gas mass measured within r_(500) (M_(g,500)), and the new proxy, Y_X, which is a simple product of T_X and M_(g,500) and is related to the total thermal energy of the ICM. We use mock Chandra images constructed for a sample of clusters simulated with the Eulerian N-body+gasdynamics adaptive mesh refinement ART code in the concordance ΛCDM cosmology. The simulations achieve high spatial and mass resolution and include radiative cooling, star formation, and other processes accompanying galaxy formation. Our analysis shows that simulated clusters exhibit a high degree of regularity and tight correlations between the considered observables and total mass. The normalizations of the M_(500)-T_X, M_(g,500)-T_X, and M_(500)-Y_X relations agree to better than ≈10%-15% with the current observational measurements of these relations. Our results show that Y_X is the best mass proxy with a remarkably low scatter of only ≈5%-7% in M500 for a fixed Y_X, at both low and high redshifts and regardless of whether clusters are relaxed or not. In addition, we show that redshift evolution of the Y_(X)-M_(500) relation is close to the self-similar prediction, which makes Y_X a very attractive mass indicator for measurements of the cluster mass function from X-ray-selected samples.

Item Type:Article
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Nagai, Daisuke0000-0002-6766-5942
Additional Information:© 2006 American Astronomical Society. Received 2006 April 12; accepted 2006 May 26. We would like to thank an anonymous referee for a careful reading of the manuscript and constructive comments. This project was supported by the National Science Foundation (NSF) under grants AST 02-06216 and AST 02-39759, by NASA through grant NAG5-13274, and by the Kavli Institute for Cosmological Physics at the University of Chicago. A. V. is supported by the NASA grant NAG5-9217 and contract NAS8-39073. D. N. is supported by the Sherman Fairchild postdoctoral fellowship at Caltech. The cosmological simulations used in this study were performed on the IBM RS/6000 SP4 system (copper) at the National Center for Supercomputing Applications (NCSA). We have made extensive use of the NASA Astrophysics Data System and preprint server.
Funding AgencyGrant Number
NSFAST 02-06216
NSFAST 02-39759
Kavli Institute for Cosmological PhysicsUNSPECIFIED
Sherman Fairchild FoundationUNSPECIFIED
Subject Keywords:cosmology: theory; galaxies: clusters: general; galaxies: evolution; methods: numerical; X-rays: galaxies: clusters
Issue or Number:1
Record Number:CaltechAUTHORS:20110427-152930882
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Official Citation:A New Robust Low-Scatter X-Ray Mass Indicator for Clusters of Galaxies Andrey V. Kravtsov et al. 2006 ApJ 650 128
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:23484
Deposited On:28 Apr 2011 17:20
Last Modified:09 Nov 2021 16:15

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