A COMPREHENSIVE STUDY OF BROAD ABSORPTION LINE QUASARS. I. PREVALENCE OF He I* ABSORPTION LINE MULTIPLETS IN LOW-IONIZATION OBJECTS
文献类型：期刊论文
| 作者 | Liu, Wen-Juan1,2; Zhou, Hongyan1,2; Ji, Tuo1,2; Yuan, Weimin3 ; Wang, Ting-Gui1; Jian, Ge4; Shi, Xiheng2; Zhang, Shaohua2; Jiang, Peng1,2; Shu, Xinwen5,6
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| 刊名 | ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
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| 出版日期 | 2015-03-01 |
| 卷号 | 217期号:1 |
| 关键词 | galaxies: active quasars: absorption lines quasars: general |
| 英文摘要 | Neutral helium multiplets, He I*lambda lambda 3189, 3889, 10830, are very useful diagnostics for the geometry and physical conditions of the absorbing gas in quasars. So far only a handful of He I* detections have been reported. Using a newly developed method, we detected the He I*lambda 3889 absorption line in 101 sources of a well-defined sample of 285 Mg II broad absorption line (BAL) quasars selected from SDSS DR5. This has increased the number of He I*BAL quasars by more than one order of magnitude. We further detected He I*lambda 3189 in 50% (52/101) of the quasars in the sample. The detection fraction of He I* BALs in Mg II BAL quasars is similar to 35% as a whole, and it increases dramatically with increasing spectral signal-to-noise ratio (S/N), from similar to 18% at S/N. 10 to similar to 93% at S/N >= 35. This suggests that He I* BALs could be detected in most Mg II LoBAL quasars, provided the spectra S/N is high enough. Such a surprisingly high He I* BAL fraction is actually predicted from photoionization calculations based on a simple BAL model. The result indicates that He I* absorption lines can be used to search for BAL quasars at low z, which cannot be identified by ground-based optical spectroscopic surveys with commonly seen UV absorption lines. Using He I*lambda 3889, we discovered 19 BAL quasars at z < 0.3 from the. available SDSS spectral database. The fraction of He I* BAL quasars is similar to that of LoBAL objects. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000353466600011 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/5769]  |
| 专题 | 国家天文台_空间科学研究部 |
| 作者单位 | 1.Chinese Acad Sci, Univ Sci & Technol China, Dept Astron, Key Lab Res Galaxies & Cosmol, Hefei 230026, Anhui, Peoples R China 2.Polar Res Inst China, Shanghai 200136, Peoples R China 3.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 4.Univ Florida, Dept Astron, Bryant Space Sci Ctr 211, Gainesville, FL 32611 USA 5.CEA Saclay, DSM Irfu, Serv Astrophys, F-91191 Gif Sur Yvette, France 6.Anhui Normal Univ, Dept Phys, Wuhu 241000, Anhui, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liu, Wen-Juan,Zhou, Hongyan,Ji, Tuo,et al. A COMPREHENSIVE STUDY OF BROAD ABSORPTION LINE QUASARS. I. PREVALENCE OF He I* ABSORPTION LINE MULTIPLETS IN LOW-IONIZATION OBJECTS[J]. ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES,2015,217(1). |
| APA | Liu, Wen-Juan.,Zhou, Hongyan.,Ji, Tuo.,Yuan, Weimin.,Wang, Ting-Gui.,...&Zhao, Wen.(2015).A COMPREHENSIVE STUDY OF BROAD ABSORPTION LINE QUASARS. I. PREVALENCE OF He I* ABSORPTION LINE MULTIPLETS IN LOW-IONIZATION OBJECTS.ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES,217(1). |
| MLA | Liu, Wen-Juan,et al."A COMPREHENSIVE STUDY OF BROAD ABSORPTION LINE QUASARS. I. PREVALENCE OF He I* ABSORPTION LINE MULTIPLETS IN LOW-IONIZATION OBJECTS".ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES 217.1(2015). |
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来源：国家天文台
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