论文标题
强大的射电星系中的parsec-Scale HI流出
The parsec-scale HI outflows in powerful radio galaxies
论文作者
论文摘要
在许多射电星系中吸收中，已经观察到了中性原子氢（HI）的大量流出，被认为是AGN反馈的标志。 KPC尺度上的这些流出尚未进行详细研究，因为它们需要在空间上解决高角度的分辨率观测值。在某些无线电AGN中，它们可能是无线电飞机与星际介质相互作用的结果。我们已经使用了一个全局的VLBI阵列来绘制一小部分的年轻和重新启动的射电星系样本中的HI流出，以前我们以VLA和WSRT观察到，并以较低的分辨率观察到。在这里，我们报告了4C52.37和3C293的发现，并讨论了包括先前发布的资源4C12.50和3C236的样本。对于4C52.37，我们提出了有史以来的第一个HI VLBI观察结果，该观察结果以云层的形式回收了大多数流出的HI气体，向AGN的中央100％。相对于系统性速度，云层的蓝色最高为600 km/s。 3C293在我们的VLBI观察结果中基本解决了，但是我们发现，朝向VLBI核心，有些超出的Hi Gas Blueshift相对于系统性速度，最高为300 km/s。我们还发现迹象表明HI流量已扩展。总体而言，我们发现我们的VLBI观察发现的HI气体比例在我们的样本中差异很大。在所有情况下，我们都会发现证据表明流出气体和静态气体的结构结构与数值模拟的预测一致。流出至少包括相对紧凑的云（10^4-10^5msun）的至少成分，通常是在核心几十个PC（投影）上观察到的。我们还发现，HI流出可能具有弥漫性组件，尤其是在较大的来源中。我们的结果支持这样的解释，即我们在喷气主义相互作用的演变中观察到这些AGN。
Massive outflows of neutral atomic hydrogen (HI) have been observed in absorption in a number of radio galaxies and are considered a signature of AGN feedback. These outflows on kpc-scales have not been investigated in great detail as they require high-angular resolution observations to be spatially resolved. In some radio AGN, they are likely the result of the radio jets interacting with the interstellar medium. We have used a global VLBI array to map the HI outflow in a small sample of young and restarted radio galaxies which we previously observed with the VLA and the WSRT at lower resolution. Here, we report on our findings for 4C52.37 and 3C293 and we discuss the sample including the previously published sources 4C12.50 and 3C236. For 4C52.37, we present the first-ever HI VLBI observation which recovered the majority of the outflowing HI gas in form of clouds towards the central 100pc of the AGN. The clouds are blue-shifted by up to 600km/s with respect to the systemic velocity. 3C293 is largely resolved out in our VLBI observation, but we detect, towards the VLBI core, some outflowing HI gas blueshifted with respect to the systemic velocity by up to 300km/s. We also find indications that the HI outflow is extended. Overall, we find that the fraction of HI gas recovered by our VLBI observation varies significantly within our sample. In all cases we find evidence for a clumpy structure of both the outflowing and the quiescent gas, consistent with predictions from numerical simulations. The outflows include at least a component of relatively compact clouds (10^4-10^5Msun) often observed already at a few tens of pc (in projection) from the core. We also find indications that the HI outflow might have a diffuse component, especially in larger sources. Our results support the interpretation that we observe these AGNs at different stages in the evolution of the jet-ISM interaction.
