Observational Constraints on the ICM Temperature Enhancement by Cluster Mergers

Nobuhiro Okabe; Keiichi Umetsu

doi:10.1007/978-3-540-73484-0_50

paper

Observational Constraints on the ICM Temperature Enhancement by Cluster Mergers

arXiv:astro-ph/0702651 · doi:10.1007/978-3-540-73484-0_50

Abstract

We present results from a combined weak lensing and X-ray analysis of the merging cluster A1914 at a redshift of $z = 0.1712$ based on $R$ -band imaging data with Subaru/Suprime-Cam and archival Chandra X-ray data. Based on the weak-lensing and X-ray data we explore the relationships between cluster global properties, namely the gravitational mass, the bolometric X-lay luminosity and temperature, the gas mass and the gas mass fraction, as a function of radius. We found that the gas mass fractions within $r_{2500}$ and $r_{vir}$ are consistent with the results of earlier X-ray cluster studies and of cosmic microwave background studies based on the WMAP observations, respectively. However, the observed temperature, $k_{B} T_{ave} = 9.6 \pm 0.3 keV$ , is significantly higher than the virial temperature, $k_{B} T_{vir} = 4.7 \pm 0.3 keV$ derived from the weak lensing distortion measurement. The X-ray bolometric luminosity and temperature ( $L_{X} - T$ ) relation is consistent with the $L_{X} - T$ relation derived by previous statistical X-ray studies of galaxy clusters. Such correlations among the global cluster properties are invaluable observational tools for studying the cluster merger physics. Our results demonstrate that the combination of X-ray and weak-lensing observations is a promising, powerful probe of the physical processes associated with cluster mergers as well as of their mass properties.

3 pages, To appear in the Proceedings of "Heating vs. Cooling in Galaxies and Clusters of Galaxies", August 2006, Garching (Germany)

Observational Constraints on the ICM Temperature Enhancement by Cluster Mergers

Abstract

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