B3 0749+460A: A New Repeat “Changing-look” Active Galactic Nucleus Associated with X-Ray Spectral Slope Variations

作     者：J.Wang W.K.Zheng D.W.Xu T.G.Brink A.V.Filippenko C.Gao S.S.Sun J.Y.Wei J.Wang;W.K.Zheng;D.W.Xu;T.G.Brink;A.V.Filippenko;C.Gao;S.S.Sun;J.Y.Wei

作者机构：Guangxi Key Laboratory for Relativistic AstrophysicsSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China Key Laboratory of Space Astronomy and TechnologyNational Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of AstronomyUniversity of CaliforniaBerkeleyCA 94720-3411USA School of Astronomy and Space ScienceUniversity of Chinese Academy of SciencesBeijing 100049China Miller Institute for Basic Research in ScienceUniversity of CaliforniaBerkeleyCA 94720USA 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2022年第22卷第1期

页      面：114-125页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：support from the National Key Research and Development Project of China (grant 2020YFE0202100) supported by the National Natural Science Foundation of China (Grants No.11773036 and 12173009) Strategic Pioneer Program on Space Science Chinese Academy of Sciences,grants XDA15052600 and XDA15016500 supported by the Natural Science Foundation of Guangxi(2020GXNSFDA238018) the Bagui Young Scholars Program supported by the Open Project Program of the Key Laboratory of Optical Astronomy,NAOC,CAS supported by the Christopher R.Redlich Fund and the Miller Institute for Basic Research in Science (in which A.V.F.is a Senior Miller Fellow) funded by the National Aeronautics and Space Administration (NASA) partially supported by a generous gift from Google 

主　　题：galaxies:Seyfert galaxies:nuclei (galaxies:)quasars:emission lines (galaxies:)quasars:individual(B30749+460A) X-rays:galaxies 

摘      要：Here we report an identification of B3 0749+460 A as a new double-peaked local changing-look active galactic nucleus(CL-AGN) in terms of our multi-epoch spectroscopic analysis. By comparing our new spectra taken in 2021 with the ones taken by the Sloan Digital Sky Survey in 2004, BOSS in 2013 and Ma NGA in 2016, we reveal type transitions of Seyfert(Sy) 1.9 → Sy1.8 → Sy1.9. In the transitions, the classical broad Hα emission fades away after 2013 and disappears in our 2021 spectrum, although the absence of broad Hβ can be traced back to at least 2016. A follow-up observation in X-rays by the Swift/XRT reveals that(1) the X-ray emission level gradually decreased since 2005;and(2)the X-ray spectrum is soft in the optical turn-off state and hard in the turn-on state. We argue that the disappearance of the classical broad Hα emission can be likely explained by the disk-wind broad-line-region model, in which the CL phenomenon is sensitive to luminosity in individual AGNs.