论文标题
Chandra揭示了一个发光的Compton-Thick QSO，在$ z = 4 $ starbursting protocluster中为$lyα$ blob提供动力
Chandra reveals a luminous Compton-thick QSO powering a $Lyα$ blob in a $z=4$ starbursting protocluster
论文作者
论文摘要
当地宇宙中的星系簇来自高红移过度密度区域，称为原始群体。预计原始群体中的大气管和高率的星系相互作用有望触发恒星形成活性和宿主星系中的发光SMBH积聚。我们调查了$ z = 4 $的富含气体和星空的原始群集的AGN含量，称为遥远的红色核心（DRC）。我们观察到Chandra（139 Ks）的结构的13个成员，并在其中搜索了发光和可能被遮盖的AGN。我们还测试了隐藏的AGN是否可以用刚果民主共和国VLT/MUSE检测到的$LYα$ Blob（实验室）为供电。我们发现了DRC的两个最丰富的燃气成员，名为DRC-1和DRC-2，发现了X射线排放。它们俩都在高分辨率ALMA和HST观测值中分为多个相互作用的团块。特别是，发现DRC-2托管发光（$ l_ {2-10 \，\ Mathrm {kev}}} \ oft3 \ times10^{45} \，\ Mathrm {erg {erg {erg \，s^{ - 1}}} $ （$ n_h \ gtrsim10^{24} \，\ mathrm {cm^{ - 2}} $）qSO，与在所有宇宙时代已知的最发光的QSO相媲美。 DRC成员之间的AGN分数与较低的红移原始群体的结果一致。但是，X射线堆叠分析表明，在Chandra未单独检测到的其他DRC星系中，SMBH积聚也可能发生。我们的结果表明，在原始群集成员中，大气管，星系相互作用以及发光和遮盖的核活动之间存在牢固的联系。在DRC-2中检测到的强大而模糊的QSO可能正在通过VLT/MUSE检测到的附近实验室的动力，这可能是通过光电离。但是，我们建议弥漫性$lyα$排放可能是由于drc-2在$ \ 10 $ kpc量表上发射的大量流出所震惊的气体。
Galaxy clusters in the local universe descend from high-redshift overdense regions known as protoclusters. The large gas reservoirs and high rate of galaxy interaction in protoclusters are expected to trigger star-formation activity and luminous SMBH accretion in the host galaxies. We investigated the AGN content of a gas-rich and starbursting protocluster at $z=4$, known as the Distant Red Core (DRC). We observed with Chandra (139 ks) the 13 identified members of the structure, and searched for luminous and possibly obscured AGN among them. We also tested whether a hidden AGN can power the $Lyα$ blob (LAB) detected with VLT/MUSE in the DRC. We detected obscured X-ray emission from the two most gas-rich members of the DRC, named DRC-1 and DRC-2. Both of them are resolved into multiple interacting clumps in high-resolution ALMA and HST observations. In particular, DRC-2 is found to host a luminous ($L_{2-10\,\mathrm{keV}}\approx3\times10^{45}\,\mathrm{erg\,s^{-1}}$) Compton-thick ($N_H\gtrsim10^{24}\,\mathrm{cm^{-2}}$) QSO, comparable to the most luminous QSOs known at all cosmic times. The AGN fraction among DRC members is consistent with results found for lower redshift protoclusters. However, X-ray stacking analysis reveals that SMBH accretion is likely also taking place in other DRC galaxies that are not detected individually by Chandra. Our results point toward the presence of a strong link between large gas reservoirs, galaxy interactions, and luminous and obscured nuclear activity in protocluster members. The powerful and obscured QSO detected in DRC-2 is likely powering the nearby LAB detected with VLT/MUSE, possibly through photoionization; however, we propose that the diffuse $Lyα$ emission may be due to gas shocked by a massive outflow launched by DRC-2 over a $\approx10$ kpc scale.
