Study of Poor Cluster of Galaxies with X-ray

以下是用ASCA.1对早期型星系的观测得到的新结果。x射线光谱由低温等离子体成分和硬成分组成。2.硬组分以LMXB.3为主。重元素的丰度大约是太阳的一半。4.x射线光度与等离子体成分的温度呈正相关。在室女座星系团中心的M87的ASCA观测显示如下：1.M87中的x射线发射等离子体由一个以星团引力为界的高温成分和一个以M87.2为界的低温成分组成。在M87中心可以看到明显的铁浓度。贫星系团所含的重金属被认为是从原始星系中喷射出来的。星爆星系是这种早期星系的原型。对星暴星系M82的观测结果如下：1.预计由ⅱ型SN合成的氧谱线较弱。2.铁的含量很低。3.另一方面，硅和磺胺含量丰富。4.结果表明，贫弱星系团中金属的起源不能简单地用星暴星系的抛射来解释。在z=0.194处对遥远的贫星系团MS0839.8的观测结果如下：1.在近星团和远星团之间，温度和x射线光度没有差别。2.结果表明，从z=0.2到现在，没有发生过强烈的演化。

Following new results were obtained from the observations of early type galaxies with ASCA.1.X-ray spectrum consists of a low temperature plasma component and a hard component. 2.The hard component is dominated by LMXB.3.Abundances of heavy elements are about a half solar value. 4.A positive correlation is seen between X-ray luminosity and temperature of the plasma component. ASCA observation of M87 at the center of the Virgo cluster of galaxies shows as follows ; 1.X-ray emitting plasma in M87 consists of a high temperature component bounded by the cluster gravity and a low temperature component bounded by M87.2.Apparent iron concentration at the M87 center is seen. Heavy metals contained by poor clusters are thought to be ejected from primordial-galaxies. Starburst galaxies are proto-type of such early phase of galaxies. Observations of the starburst galaxy M82 shows following results ; 1.Oxygen lines expected to be synthesized by type II SN are weak. 2.Iron abundance is low. 3.On the other hand, silicon and sulfa are rich. 4.The results indicate that the origin of metals in poor clusters cannot be explained simply by ejection from starburst galaxies. The observation of a distant poor cluster of galaxies MS0839.8 at z=0.194 shows the following results ; 1.No difference on temperature and X-ray luminosity between near and distant clusters is seen. 2.The result implies no strong evolution has not been occurred from z=0.2 until the present.