一个$z= 2.5$原星系团的综合气体表征：一个在维里化开始时被捕获的星系团核心？
Comprehensive Gas Characterization of a $z= 2.5$ Protocluster: A Cluster Core Caught in the Beginning of Virialization?
摘要：
为了将星系团与它们的祖先原星系团联系起来，我们必须限制它们的成员星系内的恒星形成历史和维里坍缩的时间尺度。在本文中，我们使用ALMA尘埃连续体和新的VLA CO（1-0）观测到的两个与结构相关的细丝，有时被称为“$z=2.5$”原星团，在COSMOS领域的复杂的恒星形成特性的特征。我们特别关注原星系团的“核心”，这是以前被认为是最高的红移真正的星系团跟踪扩展的X射线发射在一个堆叠的钱德拉/XMM图像。我们重新分析了这些数据，并驳斥了这些说法，发现至少有40个$\pm$ 17%的扩展X射线源在这个红移产生类似的光度和大小，而不是从逆康普顿散射最近熄灭的射电星系，而不是集群内的介质。使用辅助COSMOS数据，我们还限制了两个灯丝的八个组成星系的SED从静止帧UV到无线电。我们没有发现证据表明核心中的恒星形成效率提高，并得出结论，组成星系已经是大质量的（M $_{\star} \approx 10^{11} M_{\odot}$），分子气体库$>10^{10} M_{\odot}$将在200-400百万年内耗尽。最后，我们计算了在$z=2.5$的嵌套核心的晕质量，并得出结论，它将崩溃成2-9个$\times 10^{14} M_{\odot}$的集群，相当于在$z=0$的后发座集群的大小，并占至少50%的总估计晕质量的扩展的“扩展”结构。
英文摘要：
In order to connect galaxy clusters to their progenitor protoclusters, we must constrain the star formation histories within their member galaxies and the timescale of virial collapse. In this paper we characterize the complex star-forming properties of a $z=2.5$ protocluster in the COSMOS field using ALMA dust continuum and new VLA CO(1-0) observations of two filaments associated with the structure, sometimes referred to as the "Hyperion" protocluster. We focus in particular on the protocluster "core" which has previously been suggested as the highest redshift bona fide galaxy cluster traced by extended X-ray emission in a stacked Chandra/XMM image. We re-analyze this data and refute these claims, finding that at least 40 $\pm$ 17% of extended X-ray sources of similar luminosity and size at this redshift arise instead from Inverse Compton scattering off recently extinguished radio galaxies rather than intracluster medium. Using ancillary COSMOS data, we also constrain the SEDs of the two filaments' eight constituent galaxies from the rest-frame UV to radio. We do not find evidence for enhanced star formation efficiency in the core and conclude that the constituent galaxies are already massive (M$_{\star} \approx 10^{11} M_{\odot}$), with molecular gas reservoirs $>10^{10} M_{\odot}$ that will be depleted within 200-400 Myr. Finally, we calculate the halo mass of the nested core at $z=2.5$ and conclude that it will collapse into a cluster of 2-9 $\times 10^{14} M_{\odot}$, comparable to the size of the Coma cluster at $z=0$ and accounting for at least 50% of the total estimated halo mass of the extended "Hyperion" structure.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
