-- Context. A recently discovered thin long object aligned with a nearby galaxy could be the stellar wake induced by the passage of a supermassive black hole (SMBH) kicked out from the nearby galaxy by the slingshot effect of a three-body encounter of SMBHs. Alternatively, the object could be a bulgeless edge-on galaxy coincidentally aligned with a second nearby companion. In contrast with the latter, the SMBH interpretation requires a number of unlikely events to happen simultaneously. -- Aims. We aim to assign a probability of occurrence to the two competing scenarios. -- Methods. The probability that the SMBH passage leaves a trace of stars is factorized as the product of the probabilities of all the independent events required for this to happen (PSMBH). Then, each factor is estimated individually. The same exercise is repeated with the edge-on galaxy interpretation (Pgalax). -- Results. Our estimate yields log(Pgalax/PSMBH) simeq 11.4 pm 1.6, where the error is evaluated considering that both Pgalax and PSMBH are products of a large number of random independent variables. Based on the estimated probabilities, PSMBH < 6 x 10**-17 and Pgalax > 1.4 x 10**-5, we determined the number of objects to be expected in various existing, ongoing, and forthcoming surveys, as well as among all observable galaxies (i.e., when observing between 10**6 and 2 x 10**12 galaxies). In the edge-on galaxy scenario, there are always objects to be detected, whereas in the SMBH scenario, the expectation is always compatible with zero. -- Conclusions. Despite the appeal of the runaway SMBH explanation, arguments based on the Occam's razor clearly favor the bulgeless edge-on galaxy interpretation. Our work does not rule out the existence of runaway SMBHs leaving stellar trails. It tells that the vD23 object is more likely to be a bulgeless edge-on galaxy.
JWST spectra are consistent with the edge-on star-forming galaxy scenario for the "runaway supermassive black hole"
Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）；Universidad de La Laguna（拉古纳大学）；Universidad Nacional Autónoma de México（墨西哥国立自治大学）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所）
Mega parsec relativistic jets launched from an accreting supermassive blackhole in an extreme spiral galaxy
射电星系现象与活动星系核（AGN）中发现的质量吸积、旋转的超大质量黑洞直接相关。目前还不清楚数百到数千kpc尺度的相对论性等离子体的准直喷流是如何形成的，以及为什么它们几乎总是从核球为主的椭圆星系而不是扁平螺旋星系的核中发射出来。在这里，我们发现了巨大的射电源J2345-0449（z=0.0755），这是一个清晰而极其罕见的反例，其中相对论喷流是从一个明亮而巨大的螺旋星系中喷射出来的，规模约为1.6 Mpc，是迄今为止已知的最大的。在这个没有凸起的螺旋星系中观察到的极端物理性质，例如它的高光学和红外光度、大动力学质量、快速的盘旋转和间歇性喷流活动，可能是其不寻常的形成历史的结果，它还通过从盘中吸积气体，聚集了其中心质量大于2 x 10^8太阳的黑洞。该星系非常高的中红外光度表明它正在积极地形成恒星，并仍在建造一个巨大的圆盘。我们认为，这些强大的喷气机的发射是由平流主导的，磁化吸积流在低爱丁顿率到这个异常巨大的（一个无凸起的盘星系），可能是快速旋转的中央黑洞。因此，J2345-0449是一个极其罕见的星系系统，其性质挑战了盘状星系中黑洞生长和相对论喷流形成的标准范式。因此，它提供了基本的洞察吸积盘-相对论性喷流耦合过程。
Galaxy-SMBH co-evolution in 2,435 DESI disk galaxies and merger-free BH growth in bulgeless disks
University of Oxford（牛津大学）；Lancaster University（兰卡斯特大学）；University of Edinburgh（爱丁堡大学）；Masaryk University（马萨里克大学）；University of Toronto（多伦多大学）；University of Louisville（路易斯维尔大学）；Haverford College（哈弗福德学院）；University of Utah（犹他大学）
A Wandering 35,000-Solar-Mass Black Hole Fed by a Gravitational Wake
Westlake University（西湖大学）；Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, CAS（中国科学院南美洲天文学中心，国家天文台，中国科学院）；Xiamen University（厦门大学）；Nanjing University（南京大学）；Qinghai University（青海大学）；Qujing Normal University（曲靖师范学院）
JWST Confirmation of a Runaway Supermassive Black Hole via its Supersonic Bow Shock
Yale University（耶鲁大学）；Dragonfly Focused Research Organization（龙卷风重点研究机构）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森尼天体物理中心）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；University of Toronto（多伦多大学）；Tel Aviv University（特拉维夫大学）；San José State University（圣何塞州立大学）；University of California Santa Cruz（加州大学圣克鲁兹分校）
