标题： 改变外观活动星系核中年轻射电喷流的诞生：一个种群研究 显示英文标题

标题： The birth of young radio jets in changing-look AGN: a population study

摘要： 变脸活动星系核（CLAGN）是AGN的一个稀有子集，它们显示出宽巴尔末发射线流量的显著变化。 最近对CLAGN的研究，如1ES 1927+654和Mrk 590，揭示了光学观测到的吸积率的变化伴随着射电活动的变化。 我们使用澳大利亚SKA探路者进行时域人口研究，在射电波长下对474个光谱确认的CLAGN进行了研究，利用了ASKAP VAST变源调查和甚大天线阵天空调查。 我们将这个CLAGN样本的射电特性与没有近期变脸事件的控制样本的AGN以及在VLASS中发现从射电安静转变为射电明亮的AGN进行了比较。 对于在ASKAP VAST中检测到的20个新研究的CLAGN，我们在变脸事件后的10年内没有检测到类似Mrk 590或1ES 1927+654的射电通量衰减。 对于6个红移足够低且质量足够高的CLAGN，我们排除了类似Mrk 590的爆发。 我们发现，在总体水平上，CLAGN在VAST/VLASS中的检测率更高，射电明亮的比例更低，并且在1 GHz频率下的变化率更高，与控制AGN相比。 通过VLA对射电SED的观测和Magellan光谱观测，我们没有发现CLAGN与在VLASS中从射电明亮转变为射电安静的AGN之间的联系。 我们讨论了这项研究对驱动增强吸积事件的物理机制的意义。 显示英文摘要

摘要： Changing-Look Active Galactic Nuclei (CLAGN) are a rare subset of AGN that show significant changes to the flux of broad Balmer emission lines. Recent studies of CLAGN, such as 1ES 1927+654 and Mrk 590, have revealed that changes in the optically observed accretion rate are accompanied by changes in radio activity. We present a time-domain population study of 474 spectroscopically confirmed CLAGN at radio wavelengths using the Australia SKA Pathfinder Variable and Slow Transients Survey and the Very Large Array Sky Survey. We compare the radio properties of this CLAGN sample to a control sample of AGN that have not had recent changing-look events, and to AGN that were found to have transitioned from radio-quiet to radio-loud over 10-year timescales in VLASS. For 20 newly studied CLAGN detected in ASKAP VAST, we do not detect Mrk 590 or 1ES 1927+654-like fading of the radio flux in the 10 years following changing-look events. For 6 CLAGN with a sufficiently low redshift and high enough mass, we rule out a Mrk 590-like flare. We find that at the population level, CLAGN have higher VAST/VLASS detection rates, lower fractions of radio loudness, and higher variability rates in the 1 GHz frequency compared to the control AGN. Through VLA observations of radio SEDs and Magellan spectroscopic observations, we do not find evidence of a link between CLAGN and AGN that transitioned from radio-loud to radio-quiet in VLASS. We discuss the implications of this study for the physical mechanisms that drive enhanced accretion episodes.