We review the general observational properties of clusters of galaxies and discuss the physics of the intracluster medium. We describe many aspects of the in-flight calibration of the Reflection Grating Spectrometers (RGS) on XMM-Newton. We describe the construction of the instrument response functions and develop a number of event correction algorithms. We discuss the formulation of multivariate Monte Carlo methods for use in fitting X-ray spectra of spatially-resolved sources.; We present detailed spatially-resolved spectroscopy results of the observation of Abell 1835 using the European Photon Imaging Cameras (EPIC) and the RGS as well as high resolution X-ray spectra of 13 other putative cooling-flow clusters of galaxies obtained with the RGS. The spectra exhibit strong emission from cool plasma at just below the ambient temperature, T 0, down to T0/2, but also exhibit a severe deficit of emission, relative to the predictions of the isobaric cooling-flow model at lower temperatures (T0/3). Empirically, the differential luminosity distribution is consistent with being proportional to the temperature to the power of ≈1 to 2, instead of being independent of the temperature, as expected in the standard multi-phase model. The observations suggest a much more complicated cooling process in the cores of clusters than simple isobaric radiative cooling.
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机译:我们回顾了星系团的一般观测特性,并讨论了集群内介质的物理学。我们描述了XMM-Newton上反射光栅光谱仪(RGS)的飞行中校准的许多方面。我们描述了仪器响应函数的构造,并开发了许多事件校正算法。我们讨论了用于拟合空间分辨源的X射线光谱的多元蒙特卡罗方法的公式。我们介绍了使用欧洲光子成像相机(EPIC)和RGS进行的Abell 1835观测的详细空间分辨光谱结果,以及使用RGS获得的其他13个假定的星系冷却流星团的高分辨率X射线光谱。光谱显示在低于环境温度 T italic> 0 sub>,低至 T italic> 0 sub>的低温等离子体中有很强的发射。 / 2,但相对于在较低温度( italic> T italic> 0 sub> / 3)下的等压冷却流模型的预测,也显示出严重的排放不足。从经验上讲,差异光度分布与温度成正比且与≈ 1至2的幂成正比,而不是如标准多相模型中所预期的那样与温度无关。观测结果表明,与简单的等压辐射冷却相比,簇状核的冷却过程要复杂得多。
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