AI 中文总结
研究对14个硬X射线选择的AGN在多波段的变异性进行监测，分析多时期观测数据，量化变异性，表征射电响度，评估其对黑洞活动基本平面的影响，发现核心主导发射起源，揭示不同波段变异性特征及相关过程差异。
AI 中文摘要
活动星系核（AGN）的发射在整个电磁频谱中本质上是可变的。描绘吸积盘、X射线日冕和喷流之间的耦合是理解中央引擎内能量流动的关键。我们对14个从INTEGRAL/IBIS目录中选择的硬X射线AGN在射电、光学和X射线波段的多波长变异性进行了表征，以确定这些频率之间的耦合以及变异性与中央引擎物理性质的关系，重点是射电波段。我们分析了2018 - 2020年期间来自AMI - LA在15GHz的多时期观测、ZTF在g和r波段的观测以及Swift/XRT的观测。使用归一化超额方差、分数变异性幅度和70天及200天时间尺度的墨西哥帽滤波器对变异性进行了量化。我们还对样本的射电响度进行了表征，并通过比较时间平均数据和严格同时数据评估了变异性对黑洞活动基本平面的影响。在86%的样本中检测到显著变异性，具有明显的幅度分层：分数均方根幅度在X射线中最高，中位数为30%（11 - 67%），其次是光学g和r波段，分别为19%（2 - 33%）和8.5%（0.2 - 24%），射电波段为10%（4 - 23%）。墨西哥帽分析揭示了由长期波动主导的红噪声功率谱。样本遵循预期的基本平面缩放；尽管由于随机波动个别源在关系内移动，但这种分散仅占总散射的约3%。我们的发现支持15GHz发射的核心主导起源，可能是紧凑喷流基部或磁化日冕，而变异性模式、射电响度和基本平面位置的差异指向不同的吸积/喷射过程以及日冕 - 喷流耦合程度。
英文摘要
AGN emission is intrinsically variable across the electromagnetic spectrum. Mapping the coupling between the accretion disk, the X-ray corona, and ejection flows is key to understanding the energy flow within the central engine. We characterize the multi-wavelength variability of 14 hard X-ray selected AGN from the INTEGRAL/IBIS catalog in the radio, optical, and X-ray bands, to determine the coupling between these frequencies and how variability relates to the physical properties of the central engine, with emphasis on the radio band. We analyzed multi-epoch observations from AMI-LA at 15 GHz, ZTF in the g and r bands, and Swift/XRT over 2018--2020. Variability was quantified using the normalized excess variance, the fractional variability amplitude, and the Mexican Hat filter at 70- and 200-day timescales. We also characterized the radio-loudness of the sample and evaluated the impact of variability on the Fundamental Plane of black hole activity by comparing time-averaged with strictly simultaneous data. Significant variability is detected in 86% of the sample, with a clear amplitude stratification: the fractional rms amplitude is highest in X-rays, with a median of 30% (11-67%), followed by the optical g and r bands at 19% (2-33%) and 8.5% (0.2-24%), and the radio band at 10% (4-23%). The Mexican Hat analysis reveals a red-noise power spectrum dominated by long-term fluctuations. The sample follows the expected Fundamental Plane scaling; although individual sources shift within the relation due to stochastic fluctuations, this dispersion accounts for only ~3% of the total scatter. Our findings support a core-dominated origin for the 15 GHz emission, likely a compact jet base or a magnetized corona, while differences in variability patterns, radio-loudness, and Fundamental Plane location point toward distinct accretion/ejection processes and degrees of corona-jet coupling.
Comments13 pages plus Appendix, 5 figures, 3 tables. Accepted in A&A
