Effects of Spin on Constraining the Seeds and Growth of ?109M⊙ Supermassive Black Holes in z > 6.5 Quasars
文献类型:期刊论文
作者 | Zhang,Xiaoxia1; Lu,Youjun2,3![]() |
刊名 | The Astrophysical Journal Letters
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出版日期 | 2020-10-29 |
卷号 | 903期号:1 |
ISSN号 | 2041-8205 |
关键词 | Accretion Black hole physics Early universe Galaxy nuclei Quasars Supermassive black holes |
DOI | 10.3847/2041-8213/abc077 |
英文摘要 | Abstract The existence of ?109M⊙ supermassive black holes (SMBHs) at redshift z?>?6 raises the problem of how such SMBHs can grow up within the cosmic time (<1 Gyr) from small seed BHs. In this Letter, we use the observations of 14 quasars at z?>?6.5 with mass estimates to constrain their seeds and early growth, by self-consistently considering the spin evolution and the possibility of super-Eddington accretion. We find that spin plays an important role in the growth of early SMBHs, and the constraints on seed mass and super-Eddington accretion fraction strongly depend on the assumed accretion history. If the accretion is coherent with single (or a small number of) episode(s), leading to high spins for the majority of accretion time, then the SMBH growth is relatively slow; and if the accretion is chaotic with many episodes and in each episode the total accreted mass is much less than the SMBH mass, leading to moderate/low spins, then the growth is relatively fast. The constraints on the seed mass and super-Eddington accretion fraction are degenerate. A significant fraction (?0.1%–1% in linear scale but ~3–4 dex in logarithmic scale for 103–104M⊙ seeds) of super-Eddington accretion is required if the seed mass is not ?105M⊙, and the requirements of high seed mass and/or super-Eddington accretion fraction are moderately relaxed if the accretion is chaotic. |
语种 | 英语 |
出版者 | The American Astronomical Society |
WOS记录号 | IOP:2041-8205-903-1-ABC077 |
源URL | [http://ir.bao.ac.cn/handle/114a11/62975] ![]() |
专题 | 中国科学院国家天文台 |
通讯作者 | Zhang,Xiaoxia |
作者单位 | 1.Department of Astronomy, Xiamen University, Xiamen, Fujian 361005, People's Republic of China; zhangxx@xmu.edu.cn, fangt@xmu.edu.cn 2.National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing 100101, People's Republic of China; luyj@nao.cas.cn 3.School of Astronomy and Space Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, People's Republic of China |
推荐引用方式 GB/T 7714 | Zhang,Xiaoxia,Lu,Youjun,Fang,Taotao. Effects of Spin on Constraining the Seeds and Growth of ?109M⊙ Supermassive Black Holes in z > 6.5 Quasars[J]. The Astrophysical Journal Letters,2020,903(1). |
APA | Zhang,Xiaoxia,Lu,Youjun,&Fang,Taotao.(2020).Effects of Spin on Constraining the Seeds and Growth of ?109M⊙ Supermassive Black Holes in z > 6.5 Quasars.The Astrophysical Journal Letters,903(1). |
MLA | Zhang,Xiaoxia,et al."Effects of Spin on Constraining the Seeds and Growth of ?109M⊙ Supermassive Black Holes in z > 6.5 Quasars".The Astrophysical Journal Letters 903.1(2020). |
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来源:国家天文台
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