二元AGN候选人的兴衰：PSO J334的故事.2028+1.4075
The rise and fall of a binary AGN candidate: the story of PSO J334.2028+1.4075
摘要：
明亮的高红移（z=2.06）类星体PSO J334.2028+1.4075的明显周期性光学变化导致Liu等人（2015）将这种变化解释为位于单个环双星吸积盘中的双星超大质量黑洞（SMBH）的轨道周期。在静止坐标系中，该类星体的轨道间距约为0.006秒差距，可能的螺旋时间约为7年。这样的天体将作为难以找到的SMBH双星演化的最终产物和低频引力波的潜在来源而引起高度关注。然而，通过延长变异性研究的时间基线，Liu等人（2016）后来发现PSO J334.2028+1.4075的周期性并不持久。Foord等人（2017）没有发现基于钱德拉X射线观测的二元活动星系核场景的证据。该物体也在无线电中进行了详细研究（Mooley et al. 2018），Karl G。Jansky甚大阵列（VLA）和甚长基线阵列（VLBA），揭示了一个kpc尺度的叶主导类星体，可能是一个旋进喷流，可能保留PSO J334.2028+1.4075作为一个二元SMBH候选者。在这里，我们报告我们的1.7 GHz的观察与欧洲VLBI网络（EVN），补充VLBA数据在更高的频率，并讨论目前的知识，这个有趣的对象的性质。
英文摘要：
Apparently periodic optical variations of the luminous high-redshift (z=2.06) quasar PSO J334.2028+1.4075 led Liu et al. (2015) to interpret the variability as the orbital period of a binary supermassive black hole (SMBH) residing in a single circumbinary accretion disk. The proposed orbital separation was around 0.006 pc, and the possible inspiral time about 7 yr in the rest frame of the quasar. Such objects would be of high interest as the difficult-to-find end products of binary SMBH evolution, and potential sources of low-frequency gravitational waves. However, extending the time baseline of the variability study, Liu et al. (2016) later found that the periodicity of PSO J334.2028+1.4075 does not remain persistent. Foord et al. (2017) did not find evidence for the binary active galactic nucleus scenario based on Chandra X-ray observations. The object has also been studied in detail in the radio (Mooley et al. 2018) with the Karl G. Jansky Very Large Array (VLA) and the Very Long Baseline Array (VLBA), revealing a lobe-dominated quasar at kpc scales, and possibly a precessing jet, which might retain PSO J334.2028+1.4075 as a binary SMBH candidate. Here we report on our 1.7-GHz observation with the European VLBI Network (EVN) which complements the VLBA data taken at higher frequencies, and discuss the current knowledge about the nature of this interesting object.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
