Multi-wavelength study of XMMU J2235.3-2557: the most massive galaxy cluster at z > 1
Multi-wavelength study of XMMU J2235.3-2557: the most massive galaxy cluster at z > 1
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DOI：
10.1051/0004-6361/200913099
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发表时间：
2009-10
影响因子：
6.5
通讯作者：
P. Rosati;P. Tozzi;R. Gobat;Joana S. Santos;M. Nonino;R. Demarco;C. Lidman;C. Lidman;C. Mullis;V. Strazzullo;H. Böhringer;R. Fassbender;Kyle S. Dawson;Masayuki Tanaka;J. Jee;H. Ford;G. Lamer;A. Schwope
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作者：
P. Rosati;P. Tozzi;R. Gobat;Joana S. Santos;M. Nonino;R. Demarco;C. Lidman;C. Lidman;C. Mullis;V. Strazzullo;H. Böhringer;R. Fassbender;Kyle S. Dawson;Masayuki Tanaka;J. Jee;H. Ford;G. Lamer;A. Schwope
上下文星系团XMMU J2235.3−2557（以下简称XMM 2235），经光谱确认z = 1.39，是最遥远的X射线选择星系团之一。它一直是地面和空间设施多波长观测活动的中心。目标。我们的特征的被动成员的星系人口，热气体的物理性质和金属丰度，和系统的总质量使用成像数据与HST/ACS（i775和z 850波段）和VLT/ISAAC（J和KS波段），广泛的光谱数据与VLT/FORS 2，和深（196 ks）钱德拉观测。方法.钱德拉的数据可以很好地测量温度和金属丰度，并将X射线表面亮度轮廓追踪到1 °（或500 kpc），从而可以可靠地估计质量。在34个光谱确认的星系团成员的总样本中，我们选择了16个被动星系（没有可检测的[OII]），位于ACS覆盖范围的中心2？（或1 Mpc）内，并通过光谱合成模型模拟它们的分光光度数据来推断核心内外星系子样本的星星形成历史。结果钱德拉的数据显示出一个规则的细长形态，非常类似于核心星系的分布，有一个显着的冷核心。我们测量了kT = 8.6 + 1.3 −1.2 keV（68%置信度）的全局X射线温度，我们发现这对X射线光谱分析中涉及的几个系统是稳健的。通过探测钱德拉光谱中的静止框架6.7 keV铁K线，我们测量到金属丰度Z = 0.26 + 0.20 −0.16 Z�。在可能的流体静力平衡假设中，我们得到了Mtot（1）的总质量，包括星系人口和团内气体的重子含量，处于宇宙当前年龄的1/3的显著高级演化阶段。
Context. The galaxy cluster XMMU J2235.3−2557 (hereafter XMM2235), spectroscopically confirmed at z = 1.39, is one of the most distant X-ray selected galaxy clusters. It has been at the center of a multi-wavelength observing campaign with ground and space facilities. Aims. We characterize the galaxy populations of passive members, the thermodynamical properties and metal abundance of the hot gas, and the total mass of the system using imaging data with HST/ACS (i775 and z850 bands) and VLT/ISAAC (J and KS bands), extensive spectroscopic data obtained with VLT/FORS2, and deep (196 ks) Chandra observations. Methods. Chandra data allow temperature and metallicity to be measured with good accuracy and the X-ray surface brightness profile to be traced out to 1 � (or 500 kpc), thus allowing the mass to be reliably estimated. Out of a total sample of 34 spectroscopically confirmed cluster members, we selected 16 passive galaxies (without detectable [OII]) within the central 2 � (or 1 Mpc) with ACS coverage, and inferred star formation histories for subsamples of galaxies inside and outside the core by modeling their spectrophotometric data with spectral synthesis models. Results. Chandra data show a regular elongated morphology, closely resembling the distribution of core galaxies, with a significant cool core. We measure a global X-ray temperature of kT = 8.6 +1.3 −1.2 keV (68% confidence), which we find to be robust against several systematics involved in the X-ray spectral analysis. By detecting the rest frame 6.7 keV Iron K line in the Chandra spectrum, we measure a metallicity Z = 0.26 +0.20 −0.16 Z� . In the likely hypothesis of hydrostatic equilibrium, we obtain a total mass of Mtot( 1, with a baryonic content, both its galaxy population and intracluster gas, in a significantly advanced evolutionary stage at 1/ 3o f the current age of the Universe.