论文标题
XMM-Newton研究红移范围内的六个巨大的X射线发光星系簇系统z = 0.25至0.5
XMM-Newton study of six massive, X-ray luminous galaxy clusters systems in the redshift range z = 0.25 to 0.5
论文作者
论文摘要
大型星系簇是有趣的天体物理和宇宙学研究对象，但相对较少。在红移范围内，z = 0.25至0.5，例如一个有利的重力镜头研究区域，已知大约100个这样的系统。他们中的大多数都在X射线检查中进行了研究。在本文中，我们在高度完整的Classix调查中研究了剩余的六个巨大簇，到目前为止尚未在X射线中观察到足够深的暴露。借助我们新的XMM-Newton观测值的数据，我们表征了它们的结构，得出了X射线特性，例如X射线光度和群集内培养基，并估算其气体和总质量。我们发现一个群集RXCJ1230.7+3439在集群郊区的三个不同的子结构中动态年轻，RXCJ1310.9+2157/rxcj1310.4+2151是一个双聚类系统。在具有子结构的系统中，很难确定质量。因此，我们讨论了几种质量估计方法，包括扩展关系。总而言之，我们发现六个研究目标中的五个确实是预期的，而最后一个集群RXCJ2116.2-0309是遥远和附近集群的密切投影，这导致了先前的质量高估。在XMM-Newton观测场中，我们还发现了三个接近目标的低红移簇，此处也对此进行了分析和描述。在RXCJ2116.2-0309领域，我们偶然发现了一个高度可变的X射线源，它在一年内将其通量降低了8倍以上。该来源很可能是AGN。
Massive galaxy clusters are interesting astrophysical and cosmological study objects, but are relatively rare. In the redshift range z = 0.25 to 0.5 which is, for example, a favourable region for gravitational lensing studies, about 100 such systems are known. Most of them have been studied in X-rays. In this paper we study the six remaining massive clusters in this redshift interval in the highly complete CLASSIX survey which have so far not been observed with sufficiently deep exposures in X-rays. With data from our new XMM-Newton observations we characterise their structures, derive X-ray properties such as the X-ray luminosity and intra-cluster medium temperature and estimate their gas and total masses. We find that one cluster, RXCJ1230.7+3439, is dynamically young with three distinct substructures in the cluster outskirts and RXCJ1310.9+2157/RXCJ1310.4+2151 is a double cluster system. Mass determination is difficult in the systems with substructure. We therefore discuss several methods of mass estimation including scaling relations. In summary we find that five of the six study targets are indeed massive clusters as expected, while the last cluster RXCJ2116.2-0309 is a close projection of a distant and a nearby cluster which has led to a previous overestimation of its mass. In the XMM-Newton observation fields we also find three low redshift clusters close to the targets which are also analysed and described here. In the field of RXCJ2116.2-0309 we discover serendipitously a highly variable X-ray source which has decreased its flux within a year by more than a factor of eight. This source is most probably an AGN.
