论文标题
更换后的Seyfert Galaxy NGC 1566的最大最大后行为
The post-maximum behaviour of the changing-look Seyfert galaxy NGC 1566
论文作者
论文摘要
我们介绍了对附近更换外观（CL）Seyfert NGC 1566的光学，UV和X射线变异性的长期多波长研究的结果2019年9月。本文集中在2018年7月之后的显着后最大行为上，当时所有乐队随着一些波动而减少。我们观察到2018年11月17日至2019年1月17日至2019年1月29日至2019年6月29日和2019年7月27日至2019年8月27日的最大后期的三个重大重新亮相。2019年3月的最低X射线通量发生在2019年3月。最低紫外线最低发生了大约3个月。它伴随着luv/lx比的降低。涵盖最大后最大光谱（2018年11月31日至2019年9月23日）显示出巨大的变化，而2018年8月2日，宽线褪色和[Fe X] 6374直到2019年3月。 2019年。有效地，为此对象观察到了两个CL状态：更改为1.2型，然后以1.8型SY返回低状态。我们建议这些变化主要是由于能量产生的波动。 2014年的估计爱丁顿比率约为0.055％，2018年的最高比率为2.8％。
We present results of the long-term multi-wavelength study of optical, UV and X-ray variability of the nearby changing-look (CL) Seyfert NGC 1566 observed with the Swift Observatory and the MASTER Global Robotic Network from 2007 to 2019. We started spectral observations with South African Astronomical Observatory 1.9-m telescope soon after the brightening was discovered in July 2018 and present here the data for the interval between Aug. 2018 to Sep. 2019. This paper concentrates on the remarkable post-maximum behaviour after July 2018 when all bands decreased with some fluctuations. We observed three significant re-brightenings in the post-maximum period during 17 Nov. 2018 - 10 Jan. 2019, 29 Apr. - 19 Jun. 2019 and 27 Jul.- 6 Aug. 2019. An X-ray flux minimum occurred in Mar. 2019. The UV minimum occurred about 3 months later. It was accompanied by a decrease of the Luv/Lx ratio. New post-maximum spectra covering (31 Nov. 2018 - 23 Sep. 2019) show dramatic changes compared to 2 Aug. 2018, with fading of the broad lines and [Fe X]6374 until Mar. 2019. These lines became somewhat brighter in Aug.-Sep. 2019. Effectively, two CL states were observed for this object: changing to type 1.2 and then returning to the low state as a type 1.8 Sy. We suggest that the changes are due mostly to fluctuations in the energy generation. The estimated Eddington ratios are about 0.055% for minimum in 2014 and 2.8% for maximum in 2018.
