Several active galactic nuclei (AGN) with multiple sets of emission lines separated by over 2000 km/s have been observed recently. These have been interpreted as being due to massive black hole (MBH) recoil following a black hole merger, MBH binaries, or chance superpositions of AGN in galaxy clusters. Moreover, a number of double-peaked AGN with velocity offsets of ~ a few 100 km/s have also been detected and interpreted as being due to the internal kinematics of the narrow line regions or MBH binary systems. Here we reexamine the superposition model. Using the Millennium Run we estimate the total number of detectable AGN pairs as a function of the emission line offset. We show that AGN pairs with high velocity line separations up to ~2000 km/s are very likely to be chance superpositions of two AGN in clusters of galaxies for reasonable assumptions about the relative fraction of AGN. No superimposed AGN pairs are predicted for velocity offsets in excess of ~3000 km/s as the required AGN fractions would violate observational constraints. The high velocity AGN pair numbers predicted here are competitive with those predicted from the models relying on MBH recoil or MBH binaries. However, the model fails to account for the largest emission line velocity offsets that require the presence of MBH binaries.
Boson star-black hole binaries: initial data and head-on collisions
Hangzhou Institute for Advanced Study (HIAS), University of Chinese Academy of Sciences (UCAS)（杭州高等研究院，中国科学院大学）；Institute of Theoretical Physics, Chinese Academy of Sciences (CAS)（中国科学院理论物理研究所）；University of Chinese Academy of Sciences (UCAS)（中国科学院大学）
The background gas humming and multi-messenger transients of stalled supermassive black hole binaries
Universitat Politècnica de València（巴伦西亚理工大学）；Max Planck Institute for Extraterrestrial Physics（马克斯·普朗克地外物理研究所）；Dipartimento di Fisica e Astronomia “Galileo Galilei”, Univ. di Padova（帕多瓦大学伽利略·伽利莱物理与天文学系）；Fesenkov Astrophysical Institute（费森可夫天文物理研究所）
On the complementarity of pulsar timing and space laser interferometry for the individual detection of supermassive black hole binaries
脉冲星定时阵列（PTA）和空间激光干涉测量（SLI）都是研究超大质量黑洞双星（SMBHB）产生的引力波的目标。先前已经提出了一种可能性，即首先由PTA跟踪单个SMBHB，通过inspiral，然后由SLI跟踪单个SMBHB，直到合并和振铃。虽然边界参数是由当前的PTA或即将到来的平方公里阵列（SKA），并由新的引力观测站（NGO），来自激光干涉仪空间天线（LISA），本文还讨论了顺序检测超出特定的项目限制。我们考虑PTA-SKA，它的灵敏度从10^（-9）到p x 10^（-7）Hz（p=4，8），以及SLI，它的工作频率从s x 10^（-5）到1 Hz（s = 1，3）。在2 x 10^（8）- 2 x 10^（9）太阳质量范围内的SMBHB（质量被归一化为（1+z）因子，红移位于z = 0.2和z=1.5之间）从PTA-SKA移动到SLI带的时间从2个月到50年不等。通过结合三个超大质量黑洞（SMBH）的主机关系与三个吸积处方，九个天体物理方案形成。然后，他们涉及到三个级别的脉冲星定时残差（50，5，1纳秒），产生27例。对于1 ns的残差，顺序检测概率永远不会优于4.7 x 10^（-4）y^（-2）或3.3 x 10^（-6）y^（-2）（按合并前每年和调查年计算），分别按最佳和最差天体物理设想计算;换句话说，这意味着每46年或550年进行一次连续检测，时间与合并的最长时…
The properties of the first continuous gravitational waves: Optimizing pulsar timing observations for supermassive black hole binary detection
School of Physics, The University of Melbourne（墨尔本大学物理学院）；OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery（引力波发现ARC卓越中心）；School of Physics and Astronomy, Monash University（蒙纳士大学物理与天文学院）
