Both theoretical and observational results suggest that high-redshift radio galaxies (HzRGs) inhabit overdense regions of the universe and might be the progenitors of local, massive galaxies residing in the centre of galaxy clusters. In this paper we present CO(3–2) line observations of the HzRG TXS 0828+193 (z = 2.57) and its environment using the Atacama Large Millimeter/submillimeter Array. In contrast to previous observations, we detect CO emission associated with the HzRG and derive a molecular gas mass of (0.9±0.3) ×1010M . Moreover, we confirm the presence of a previously detected off-source CO emitting region (companion #1), and detect three new potential companions. The molecular gas mass of each companion is comparable to that of the HzRG. Companion #1 is aligned with the axis of the radio jet and has stellar emission detected by Spitzer. Thus this source might be a normal star-forming galaxy or alternatively a result of jet-induced star formation. The newly found CO sources do not have counterparts in any other observing band and could be high-density clouds in the halo of TXS 0828+193 and thus potentially linked to the large-scale filamentary structure of the cosmic web.

中文翻译：

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ALMA 探测到强大射电星系 TXS 0828+193 光晕中的分子气体

理论和观测结果都表明，高红移射电星系 (HzRG) 居住在宇宙的高密度区域，并且可能是位于星系团中心的局部大质量星系的祖先。在本文中，我们使用阿塔卡马大型毫米/亚毫米阵列对 HzRG TXS 0828+193 (z = 2.57) 及其环境进行 CO(3-2) 线观测。与之前的观察相反，我们检测到与 HzRG 相关的 CO 排放，并推导出 (0.9±0.3) ×1010M 的分子气体质量。此外，我们确认存在先前检测到的离源 CO 排放区域（伴生 #1），并检测到三个新的潜在伴生。每个伴星的分子气体质量与 HzRG 相当。伴星#1 与射电射流的轴对齐，并有被斯皮策探测到的恒星发射。因此，这个来源可能是一个正常的恒星形成星系，或者是喷射诱导恒星形成的结果。新发现的 CO 源在任何其他观测波段都没有对应物，可能是 TXS 0828+193 晕中的高密度云，因此可能与宇宙网的大尺度丝状结构有关。