Zhenzhen Qin, Haiguang Xu, Jingying Wang, Junhua Gu
In this work, we present a high spatial resolution study of a fossil cluster, SDSS J0150-1005 ($z \simeq 0.364$), based on the imaging spectroscopic analysis of \chandra\ observation. The \chandra\ X-ray image shows a relax and symmetric morphology, which indicates SDSS J0150-1005 is a well-developed galaxy cluster with no sign of recent merger. Its global gas temperature is 5.73 $\pm$ 0.80 keV, and the virial mass is 6.23 $\pm$ 1.34 $\times 10^{14} $ M$_{\odot}$ according to the isothermal model. Compared with polytropic temperature model, the mass calculated based on isothermal model overestimates 49 $\pm$ 11%. The central gas entropy, $S_{0.1r_{200}} = 143.9 \pm 18.3$ keV cm$^2$, is significantly lower than average value of the normal galaxy clusters with similar temperatures. Our results indicate the early formation epoch of SDSS J0150-1005.
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http://arxiv.org/abs/1306.1680
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