An Extreme X-Ray Variability Event of a Weak-line Quasar | |
Ni, Q.13,14; Brandt, W. N.12,13,14; Yi WM(易卫敏)1,11,14; Luo, B.8,9,10; Timlin, J. D., III13,14; Hall, P. B.7; Liu, Hezhen8,9,10; Plotkin, R. M.6; Shemmer, O.5; Vito, F.3,4 | |
刊名 | ASTROPHYSICAL JOURNAL LETTERS |
2020-02-01 | |
卷号 | 889期号:2页码:6 |
ISSN号 | 2041-8205 |
DOI | 10.3847/2041-8213/ab6d78 |
产权排序 | 第4完成单位 |
文献子类 | Article |
英文摘要 | We report the discovery of an extreme X-ray flux rise (by a factor of greater than or similar to 20) of the weak-line quasar Sloan Digital Sky Survey (SDSS) J153913.47+395423.4 (hereafter SDSS J1539+3954) at z = 1.935. SDSS J1539+3954 is the most-luminous object among radio-quiet type 1 active galactic nuclei (AGNs) where such dramatic X-ray variability has been observed. Before the X-ray flux rise, SDSS J1539+3954 appeared X-ray weak compared with the expectation from its ultraviolet (UV) flux; after the rise, the ratio of its X-ray flux and UV flux is consistent with the majority of the AGN population. We also present a contemporaneous HET spectrum of SDSS J1539+3954, which demonstrates that its UV continuum level remains generally unchanged despite the dramatic increase in the X-ray flux, and its C IV emission line remains weak. The dramatic change only observed in the X-ray flux is consistent with a shielding model, where a thick inner accretion disk can block our line of sight to the central X-ray source. This thick inner accretion disk can also block the nuclear ionizing photons from reaching the high-ionization broad emission-line region, so that weak high-ionization emission lines are observed. Under this scenario, the extreme X-ray variability event may be caused by slight variations in the thickness of the disk. This event might also be explained by gravitational light-bending effects in a reflection model. |
学科主题 | 天文学 ; 星系与宇宙学 ; 星系天文学 |
URL标识 | 查看原文 |
出版地 | TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND |
资助项目 | CXC grant[GO8-19076] ; NASA ADP grant[80NSSC18K0878] ; NSF grant[AST-1516784] ; NSFC[11673010] ; NSFC[2017-05983] ; CONICYT ; CASSACA through the Fourth call for tenders of the CAS-CONICYT Fund ; CONICYT[BasalCATA AFB-170002] |
WOS关键词 | DIGITAL SKY SURVEY ; SPECTRAL PROPERTIES ; EMISSION ; EXPLORER |
WOS研究方向 | Astronomy & Astrophysics |
语种 | 英语 |
出版者 | IOP PUBLISHING LTD |
WOS记录号 | WOS:000537504700002 |
资助机构 | CXC grant[GO8-19076] ; NASA ADP grant[80NSSC18K0878] ; NSF grant[AST-1516784] ; NSFC[11673010, 2017-05983] ; CONICYT ; CASSACA through the Fourth call for tenders of the CAS-CONICYT Fund ; CONICYT[BasalCATA AFB-170002] |
内容类型 | 期刊论文 |
源URL | [http://ir.ynao.ac.cn/handle/114a53/23387] |
专题 | 云南天文台_丽江天文观测站(南方基地) |
通讯作者 | Ni, Q. |
作者单位 | 1.Yunnan Observatories, Kunming, 650216, People's Republic of China 2.Department of Astronomy, Xiamen University, Xiamen, Fujian 361005, People's Republic of China 3.Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, CAS, Beijing 100012, People's Republic of China 4.Instituto de Astrofísica and Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile 5.Department of Physics, University of North Texas, Denton, TX 76203, USA 6.Department of Physics, University of Nevada, 1664 N. Virginia Street, Reno, NV 89557, USA 7.Department of Physics & Astronomy, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada 8.Collaborative Innovation Center of Modern Astronomy and Space Exploration, Nanjing 210093, People's Republic of China 9.Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing, Jiangsu 210093, People's Republic of China 10.School of Astronomy and Space Science, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China |
推荐引用方式 GB/T 7714 | Ni, Q.,Brandt, W. N.,Yi WM,et al. An Extreme X-Ray Variability Event of a Weak-line Quasar[J]. ASTROPHYSICAL JOURNAL LETTERS,2020,889(2):6. |
APA | Ni, Q..,Brandt, W. N..,Yi WM.,Luo, B..,Timlin, J. D., III.,...&Wu, Jianfeng.(2020).An Extreme X-Ray Variability Event of a Weak-line Quasar.ASTROPHYSICAL JOURNAL LETTERS,889(2),6. |
MLA | Ni, Q.,et al."An Extreme X-Ray Variability Event of a Weak-line Quasar".ASTROPHYSICAL JOURNAL LETTERS 889.2(2020):6. |
个性服务 |
查看访问统计 |
相关权益政策 |
暂无数据 |
收藏/分享 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论