论文标题
HI吸收与Norma最亮的星系星系
HI absorption associated with Norma's brightest cluster galaxy
论文作者
论文摘要
ESO 137-G006是冷核和动态幼年群集的最明亮的星系星系（BCG）。我们使用澳大利亚望远镜紧凑型阵列发现了与该BCG相关的原子氢（HI）吸收系。 We estimate a gas column density of $ \approx (1.3 \pm 0.2) \times 10^{20}\,T_{\rm{spin}}$ atoms cm$^{-2}$ with spin temperature, $T_{\rm{spin}} \leq 194$ K, consistent with the HI properties of other early-type galaxies and cool-core cluster BCGS。冷气的存在与簇冷却流之间的关系尚不清楚。我们的结果支持ESO 137-G006的情况可能是最近到达集群中心而不是原始BCG的情况。这种情况与与Norma的X射线亚群集的BCG广角尾部无线电裂片观察到的空间比对一致，以及在Norma的平均速度和BCG的平均速度之间的明显偏置速度偏移。
ESO 137-G006 is the brightest cluster galaxy (BCG) of the cool-core and dynamically young Norma cluster. We discover an atomic hydrogen (HI) absorption line associated with this BCG using the Australia Telescope Compact Array. We estimate a gas column density of $ \approx (1.3 \pm 0.2) \times 10^{20}\,T_{\rm{spin}}$ atoms cm$^{-2}$ with spin temperature, $T_{\rm{spin}} \leq 194$ K, consistent with the HI properties of other early-type galaxies and cool-core cluster BCGs. The relationship between the presence of cold gas and a cluster cooling flow is unclear. Our results support the scenario that ESO 137-G006 may be a recent arrival to the cluster centre and not the original BCG. This scenario is consistent with the observed spatial alignment of the BCG's wide-angle tail radio lobes with Norma's X-ray sub-cluster and the significant line-of-sight velocity offset between the mean velocity of Norma and that of the BCG.
