中红移BCG的X射线性质

The X-ray properties of BCG in middle redshift

最亮团星系(brightest cluster galaxy,BCG)的X射线起源尚不清楚.射电喷流与径移主导吸积流(advectiondominated accretion flows,ADAF)是2种主要可能的物理起源机制.2种模型中是否存在主导模型或模型间是否存在关系并不明确,而且不是所有BCG都存在X射线辐射.为探究BCG的X射线性质,进一步了解X射线物理起源机制,本文选取钱德拉塞卡X射线望远镜(Chandra X-ray observatory,简称Chandra)数据存档红移范围0.2<z<0.23的27个星系团(共30个BCGs).依据信噪比大于或等于3的标准,共6个BCGs有X射线辐射.通过研究中红移BCG的X射线与射电的性质,结果发现X射线流量与射电流量,以及X射线光度与射电光度不存在显著线性关系.中红移BCG的X射线不是射电喷流或ADAF单一起源.

The origin of X-ray emission in Brightest Cluster Galaxy （BCG） is not clear. Both radio jet model and advection-dominated accretion flows （ADAF） model are possible. It is not clear which model is dominant or whether there is any correlation between these two models. However, not all BCG demonstrate X- ray emission. Therefore, it is important to study X-ray properties of BCG and to elucidate the origin of such X- ray emissions. We therefore considered the redshift bin, 0. 2〈z〈0.23 and analyzed all 27 clusters （30 BCGs in total） recorded in Chandra archive. According to SIN ≥ 3, 6 BCGs showed X-ray emission. No linear correlation was found between flux and luminosity of X-ray and radio. Our work suggests that neither ADAF model nor radio iet model dominates in BCG X-ray emission.