论文标题
AGN活性在z〜1.6的BCG构建中的作用
The role of AGN activity in the building up of the BCG at z~1.6
论文作者
论文摘要
XDCPJ0044.0-2033是Z〜1.6最庞大的星系群之一，在过去的几年中，收集了大量的多波长光度和光谱数据。我已经报道了通过深HST光度法，SINFONI和KMOS IFU光谱范围得出的群集中心区域（〜70kpc x 70kpc）的星系成员的性质，以及Chandra X射线，ALMA和JVLA无线电数据。在集群的核心中，我们已经确定了两组星系（复杂A和复杂的B），其中七个被确认为群集成员，并具有持续合并的签名。这些星系显示出扰动的形态，其中三个显示出AGN活性的迹象。特别是，已经发现其中两个位于每个复合物的中心，它们具有发光，遮盖和高度吸收的AGN（Lambda = 0.4-0.6），表现出宽Halpha线。此外，通过复合物A中的BPT图发现了第三个光学遮挡的2型AGN。这三个AGN提供了到目前为止揭示的最接近的AGN三重量之一，最小值（最大）投影距离为10 kpc（40 kpc）。在Z〜1.6处与星系群的拥挤核心相关的高恒星形成区域中的多个AGN活性的发现表明，这些过程在塑造当地簇的中心观察到的新生最亮的簇星系中具有关键作用。根据我们的数据，XDCPJ0044.0-2033核心中的所有星系都可以形成MSTAR〜10^{12} MSUN的BCG，托管2 x 10^{8} -10^{9} MSUN的BH，以2.5 Gyrs的顺序为2.5 Gyrs的时间尺度。
XDCPJ0044.0-2033 is one of the most massive galaxy cluster at z~1.6, for which a wealth of multi-wavelength photometric and spectroscopic data have been collected during the last years. I have reported on the properties of the galaxy members in the very central region (~70kpc x 70kpc) of the cluster, derived through deep HST photometry, SINFONI and KMOS IFU spectroscopy, together with Chandra X-ray, ALMA and JVLA radio data. In the core of the cluster, we have identified two groups of galaxies (Complex A and Complex B), seven of them confirmed to be cluster members, with signatures of ongoing merging. These galaxies show perturbed morphologies and, three of them show signs of AGN activity. In particular, two of them, located at the center of each complex, have been found to host luminous, obscured and highly accreting AGN (lambda=0.4-0.6) exhibiting broad Halpha line. Moreover, a third optically obscured type-2 AGN, has been discovered through BPT diagram in Complex A. The AGN at the center of Complex B is detected in X-ray while the other two, and their companions, are spatially related to radio emission. The three AGN provide one of the closest AGN triple at z>1 revealed so far with a minimum (maximum) projected distance of 10 kpc (40 kpc). The discovery of multiple AGN activity in a highly star-forming region associated to the crowded core of a galaxy cluster at z~1.6, suggests that these processes have a key role in shaping the nascent Brightest Cluster Galaxy, observed at the center of local clusters. According to our data, all galaxies in the core of XDCPJ0044.0-2033 could form a BCG of Mstar ~ 10^{12} Msun hosting a BH of 2 x 10^{8}-10^{9}Msun, in a time scale of the order of 2.5 Gyrs.
