论文标题
不断变化的外观AGN MRK 590。i：X射线爆发的紫外线响应表明，比标准磁盘更复杂地重新处理几何形状
Flares in the changing look AGN Mrk 590. I: The UV response to X-ray outbursts suggests a more complex reprocessing geometry than a standard disk
论文作者
论文摘要
MRK 590是一种已知的更换AGN，几乎在2012年关闭了，然后在2017年部分重新燃烧成一个反复的耀斑状态，对于AGN来说是不寻常的。自2013年以来，我们的\ emph {swift}观察结果使我们能够表征积分生成的排放及其在更换外观AGN的中央引擎中的重新处理。 X射线和紫外线变异幅度高于以类似的中等积聚率在“稳态” AGN中通常观察到的那些。相反，变异性与高度积累的AGN相似。异常强的X射线与紫外线相关性表明，X射线爆发直接照亮了紫外线发射区域。我们发现证据表明，X射线由两个紫外线组件重新处理，其中一个X射线为$ \ sim $ 3天，而接近零滞后的额外再处理者则有些额外的再处理。但是，我们排除了弥漫性宽线区域连续体的重大贡献，该区域已知为真正的AGN贡献。对于标准的“ Lamp-Post”磁盘后处理模型，在黑洞附近有一个驱动连续源，预计将接近零。 That the overall UV response is dominated by the $\sim$3-day lagged component suggests a complicated reprocessing geometry, with most of the UV continuum not produced in a compact disk, as also found in recent studies of NGC 5548 and NGC 4151. Nonetheless, the observed flares display characteristic timescales of $\sim$100 rest-frame days, consistent with the expected thermal积聚磁盘中的时间尺度。
Mrk 590 is a known changing-look AGN which almost turned off in 2012, and then in 2017 partially re-ignited into a repeat flaring state, unusual for an AGN. Our \emph{Swift} observations since 2013 allow us to characterise the accretion-generated emission and its reprocessing in the central engine of a changing-look AGN. The X-ray and UV variability amplitudes are higher than those typically observed in `steady-state' AGN at similar moderate accretion rates; instead, the variability is similar to that of highly accreting AGN. The unusually strong X-ray to UV correlation suggests that the UV-emitting region is directly illuminated by X-ray outbursts. We find evidence that the X-rays are reprocessed by two UV components, with the dominant one at $\sim$3 days and a faint additional reprocessor at near-zero lag. However, we exclude a significant contribution from diffuse broad line region continuum, known to contribute for bona-fide AGN. A near-zero lag is expected for a standard `lamp-post' disk reprocessing model with a driving continuum source near the black hole. That the overall UV response is dominated by the $\sim$3-day lagged component suggests a complicated reprocessing geometry, with most of the UV continuum not produced in a compact disk, as also found in recent studies of NGC 5548 and NGC 4151. Nonetheless, the observed flares display characteristic timescales of $\sim$100 rest-frame days, consistent with the expected thermal timescale in an accretion disk.
