Supermassive black holes in cosmological simulations II: the AGN population and predictions for upcoming X-ray missions
Melanie Habouzit, Rachel S. Somerville, Yuan Li, Shy Genel, James Aird, Daniel Anglés-Alcázar, Romeel Davé, Iskren Y. Georgiev, Stuart McAlpine, Yetli Rosas-Gue… 展开作者
Melanie Habouzit, Rachel S. Somerville, Yuan Li, Shy Genel, James Aird, Daniel Anglés-Alcázar, Romeel Davé, Iskren Y. Georgiev, Stuart McAlpine, Yetli Rosas-Guevara, Yohan Dubois, Dylan Nelson, Eduardo Bañados, Lars Hernquist, Sébastien Peirani, Mark Vogelsberger
In large-scale hydrodynamical cosmological simulations, the fate of massive galaxies is mainly dictated by the modeling of feedback from active galactic nuclei (AGN). The amount of energy released by AGN feedback is proportional to the mass that has been accreted onto the BHs, but the exact sub-grid modeling of AGN feedback differs in all simulations. Whilst modern simulations reliably produce populations of quiescent massive galaxies at z<2, it is also crucial to assess the similarities and differences of the responsible AGN populations. Here, we compare the AGN population of the Illustris, TNG100, TNG300, Horizon-AGN, EAGLE, and SIMBA simulations. The AGN luminosity function (LF) varies significantly between simulations. Although in agreement with current observational constraints at z=0, at higher redshift the agreement of the LFs deteriorates with most simulations producing too many AGN of L_{x, 2-10 keV}~10^43-10^44 erg/s. AGN feedback in some simulations prevents the existence of any bright AGN with L_{x, 2-10 keV}>=10^45 erg/s (although this is sensitive to AGN variability), and leads to smaller fractions of AGN in massive galaxies than in the observations at z<=2. We find that all the simulations fail at producing a number density of AGN in good agreement with observational constraints for both luminous (L_{x, 2-10 keV}~10^43-10^45 erg/s) and fainter (L_{x, 2-10 keV}~10^42-10^43 erg/s) AGN, and at both low and high redshift. These differences can aid us in improving future BH and galaxy subgrid modeling in simulations. Upcoming X-ray missions (e.g., Athena, AXIS, and LynX) will bring faint AGN to light and new powerful constraints. After accounting for AGN obscuration, we find that the predicted number density of detectable AGN in future surveys spans at least one order of magnitude across the simulations, at any redshift.
Plato's view on supermassive black hole binaries: Exploring the faint limit of ESA's Plato space mission
Isaac Newton Group of Telescopes（牛顿望远镜小组）；Institute of Astronomy, KU Leuven（鲁汶大学天文学研究所）；Institute of Science and Technology Austria (ISTA)（奥地利科学与技术研究所）；Department of Astronomy, Columbia University（哥伦比亚大学天文学系）；Department of Physics, Columbia University（哥伦比亚大学物理学系）；Space Telescope Science Institute（太空望远镜科学研究所）；Department of Physics and Astronomy, Johns Hopkins University（约翰斯·霍普金斯大学物理与天文系）；Niels Bohr International Academy, Niels Bohr Institute（尼尔斯·玻尔国际学院，尼尔斯·玻尔研究所）；Department of Astrophysics, IMAPP, Radboud University Nijmegen（奈梅亨拉德堡德大学IMAPP天体物理系）；Max Planck Institute for Astronomy（马克斯·普朗克天文学研究所）
Probing supermassive stars and massive black hole seeds through gravitational wave inspirals
我们提出了一个新的引力波发射源：原始超大质量恒星内部致密碎片的螺旋辐射。这样的系统被认为是超大质量黑洞（SMBH）形成过程中的一个重要通道，但人们对此知之甚少。一个模型表明，在原子冷却的原始晕中，$0.1$-1 M $_\odot$ /yr的高吸积率可能导致核燃烧SMS的形成。这最终将通过相对论不稳定性发生坍缩，留下巨大的BH残留物。最近的模拟表明，超大质量恒星很少单独形成，而伴星甚至形成的黑洞可能会被捕获/吸积，并由于气体动力学摩擦而螺旋进入SMS核心。在这里，我们探讨了从这样的吸气产生的GW发射，这可能会探测SMS的形成和演化和第一个超大质量黑洞的种子。我们使用一个半解析的气体动力学摩擦模型的吸气在SMS来表征其属性。我们发现这样的来源可能是潜在的观察到即将到来的空间出生的GW探测器在其形成的红移与引力透镜的好处。密切相关的准恒星合并可能会产生更强的信号，尽管从其他高z事件中消除这种事件可能具有挑战性。
Accelerated orbital decay of supermassive black hole binaries in merging nuclear star clusters
超大质量黑洞（SMBH）的合并应该会产生宇宙中最强的引力波（GW）源。然而，它们合并的动力学是一个备受争议的话题。在这项研究中，我们使用了一套$N$体模拟遵循合并的两个核星团（NSC），每个托管SMBH在其中心。我们发现，每个SMBH周围的不同的星团的存在下有重要的后果的SMBH二进制的动力学演化：（i）之间的分离SMBH减少了几个数量级的前几个百万年的综合效应的动力摩擦和潮汐剥离的恒星所造成的阻力。事实上，这对于等质量比的双星来说是一个显著的加速，而对于不相等的质量比，例如1：10或1：100，这变得极端，传统的动力学摩擦力本身不允许绑定。(ii)随后的双星硬化是由SMBH双星和恒星之间的引力弹弓驱动的，也取决于SMBH之间的质量比。因此，有了这个额外的阻力，我们发现我们套件中的所有SMBH在哈勃时间内合并。考虑到大约50%的银河系大小的星系主机NSC，我们的结果是令人鼓舞的，即将到来的GW观测与激光干涉仪空间天线- LISA -这将检测SMBH聚结在$10^4-10^7$ $M_{\rm \odot}$质量范围。
The formation of supermassive black holes from Population III.1 seeds. IV. Self-regulated seeding from supermassive star ionizing feedback
Chalmers University of Technology（查尔姆斯理工大学）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；University of Modena & Reggio Emilia（摩德纳与雷焦艾米利亚大学）；University of Oxford（牛津大学）；University of Memphis（孟菲斯大学）；Center for Astrophysics, Harvard and Smithsonian（哈佛史密松天体物理中心）；Università degli Studi di Trieste（的里雅斯特大学）；INAF - Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）；INFN, Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）
Looking at infrared background radiation anisotropies with Spitzer II. Small scale anisotropies and their implications for new and upcoming space surveys
University of Miami（迈阿密大学）；NASA Goddard Space Flight Center（NASA戈达德太空飞行中心）；University of Maryland, College Park（马里兰大学帕克分校）；Center for Research and Exploration in Space Science and Technology, NASA/GSFC（NASA/GSFC空间科学与技术研究探索中心）；Center for Space Sciences and Technology, University of Maryland, Baltimore County（马里兰大学巴尔的摩县分校空间科学与技术中心）
