X-ray spectroscopy of the cluster of galaxies PKS 0745-191 with XMM-Newton
X-ray spectroscopy of the cluster of galaxies PKS 0745-191 with XMM-Newton
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DOI：
10.1051/0004-6361:20030862
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发表时间：
2003-08
影响因子：
6.5
通讯作者：
Yong-jun Chen;Y. Ikebe;H. Böhringer
中科院分区：
文献类型：
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作者：
Yong-jun Chen;Y. Ikebe;H. Böhringer
本文给出了星系团PKS 0745-191的XMM-牛顿观测结果。当星际柱密度接近观测允许范围的下限时，欧洲光子成像相机（EPN和EMOS）的空间分辨光谱可以用单温度热等离子体模型拟合。或者，对于N-H值略高的内部区域，可以将双组分模型拟合到光谱。温度分布图显示在团簇的中心有一个下降，从半径大于350千秒差距的大约8千电子伏下降到中心的大约4千电子伏，表明中心区域的气体正在冷却。由谱资料推断的总冷却流量仅为364（-94）（+97）M圆点年（-1），但远小于以前得到的数值。发现金属丰度从中心的0.5太阳单位减少到半径约为300千秒差距的0.2太阳单位。还提出了解投影谱，其显示出与投影谱类似的结果。X射线发射峰的位置也是扩展无线电发射的位置。对该星团高分辨率钱德拉图像的检查显示，在中心以西约3”处的X射线发射增强，无线电发射也被拉长。我们探讨可能的影响之间的相互作用的射电叶和集群内等离子体。假设气体与团簇势处于流体静力平衡，我们发现在所观测到的引力弧的临界半径范围内，总质量约为1.18 +/- 0.04 × 10（13）M圆点，但比光学透镜的结果低约2倍。我们还计算了高达0.63 r（vir）的气体质量分数分布，并获得了平均气体质量分数f（气体）= 0.22 +/- 0.02。
We present the results from XMM-Newton observations of the cluster of galaxies PKS 0745-191. The spatially resolved spectra from the European Photon Imaging Cameras ( both EPN and EMOS) can be fitted with a single temperature thermal plasma model when the interstellar column density is closer to the lower limit of the range allowed by observations. Alternatively, a two-component model can be fitted to the spectra from the inner region for slightly higher values of N-H. The temperature profile shows a drop in the center of the cluster, from about 8 keV at radii larger than similar to350 kpc to about 4 keV at the center, indicating that the gas in the central region is cooling. The total cooling flow rate inferred from the spectral data is only 364(-94)(+97) M-circle dot yr(-1), however, much smaller than the previously obtained value. The metal abundance is found to decrease from 0.5 in solar units at the center to about 0.2 at a radius of similar to300 kpc. Deprojected spectra are also presented, which show a result similar to the projected spectra. The location of the X-ray emission peak is also the site of extended radio emission. Inspection of the higher resolution Chandra image of the cluster shows enhanced X-ray emission about 3" west of the center where also the radio emission is elongated. We explore possible implications on the interaction between the radio lobes and the intracluster plasma. Assuming that the gas is in hydrostatic equilibrium with the cluster potential, we find a total mass of about 1.18 +/- 0.04 x 10(13) M-circle dot within the critical radius of the observed gravitational arc, which is a factor similar to2 lower, however, than that from optical lensing. We also calculated the gas mass fraction profile up to 0.63 r(vir) and obtained a mean gas mass fraction f(gas) = 0.22 +/- 0.02.