LoCuSS: comparison of observed X-ray and lensing galaxy cluster scaling relations with simulations

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This article has an erratum: [erratum]

Issue		A&A Volume 482, Number 2, May I 2008


Page(s)		451 - 472
Section		Cosmology (including clusters of galaxies)
DOI		http://dx.doi.org/10.1051/0004-6361:20079103
Published online		14 February 2008

A&A 482, 451-472 (2008)
DOI: 10.1051/0004-6361:20079103

LoCuSS: comparison of observed X-ray and lensing galaxy cluster scaling relations with simulations

Y.-Y. Zhang^{1, 2}, A. Finoguenov^{1, 3}, H. Böhringer¹, J.-P. Kneib⁴, G. P. Smith⁵, R. Kneissl⁶, N. Okabe⁷, and H. Dahle⁴

¹ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany
e-mail: yyzhang@astro.uni-bornn.de
² Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
³ University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
⁴ OAMP, Laboratoire d'Astrophysique de Marseille, traverse du Siphon, 13012 Marseille, France
⁵ School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B152TT, UK
⁶ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
⁷ Astronomical institute, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan

(Received 19 November 2007 / Accepted 6 February 2008)

Abstract
The Local Cluster Substructure Survey (LoCuSS, Smith et al.) is a systematic multi-wavelength survey of more than 100 X-ray luminous galaxy clusters in the redshift range 0.14-0.3 selected from the ROSAT All Sky Survey. We used data on 37 LoCuSS clusters from the XMM-Newton archive to investigate the global scaling relations of galaxy clusters. The scaling relations based solely on the X-ray data (S-T, $S{-}Y_{\rm X}$ , $P{-}Y_{\rm X}$ , M-T, $M{-}Y_{\rm X}$ , $M{-}M_{\rm gas}$ , $M_{\rm gas}{-}T$ , L-T, $L{-}Y_{\rm X}$ , and L-M) obey empirical self-similarity and reveal no additional evolution beyond the large-scale structure growth. They also reveal up to 17 per cent segregation between all 37 clusters and non-cool core clusters. Weak lensing mass measurements are also available in the literature for 19 of the clusters with XMM-Newton data. The average of the weak lensing mass to X-ray based mass ratio is $1.09\pm 0.08$ , setting the limit of the non-thermal pressure support to $9 \pm 8$ per cent. The mean of the weak lensing mass to X-ray based mass ratio of these clusters is ~1, indicating good agreement between X-ray and weak lensing masses for most clusters, although with 31-51 per cent scatter. The scatter in the mass-observable relations ( $M{-}Y_{\rm X}$ , $M{-}M_{\rm gas}$ , and M-T) is smaller using X-ray based masses than using weak lensing masses by a factor of 2. With the scaled radius defined by the $Y_{\rm X}$ profile - $r_{500}^{ Y_{\rm X},X}$ , $r_{500}^{Y_{\rm X},{\rm wl}}$ , and $r_{500}^{Y_{\rm X},{\rm si}}$ , we obtain lower scatter in the weak lensing mass based mass-observable relations, which means the origin of the scatter is $M^{\rm wl}$ and $M^{\rm X}$ instead of $Y_{\rm X}$ . The normalization of the $M{-}Y_{\rm X}$ relation using X-ray mass estimates is lower than the one from simulations by up to 18-24 per cent at $3\sigma$ significance. This agrees with the $M{-}Y_{\rm X}$ relation based on weak lensing masses, the normalization of the latter being ~20 per cent lower than the one from simulations at ~ $2\sigma$ significance. This difference between observations and simulations is also indicated in the $M{-}M_{\rm gas}$ and M-T relations. Despite the large scatter in the comparison of X-ray to lensing, the agreement between these two completely independent observational methods is an important step towards controlling astrophysical and measurement systematics in cosmological scaling relations.

Key words: cosmology: observations -- galaxies: clusters: general -- X-rays: galaxies: clusters -- cosmology: dark matter -- gravitational lensing

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