A systematic study of the advection-dominated accretion flow for the origin of the X-ray emission in weakly magnetized low-level accreting neutron stars
文献类型：期刊论文
| 作者 | Qiao, Erlin1,2 ; Liu, B. F.1,2
|
| 刊名 | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
 |
| 出版日期 | 2020-02-01 |
| 卷号 | 492期号:1页码:615-627 |
| 关键词 | accretion, accretion discs black hole physics stars: neutron X-rays: binaries |
| ISSN号 | 0035-8711 |
| DOI | 10.1093/mnras/stz3510 |
| 英文摘要 | Observationally, the X-ray spectrum (0.5-10 keV) of low-level accreting neutron stars (NSs) (L0.5-10 kev less than or similar to 10(36) erg s(-1)) can generally be well fitted by the model with two components, i.e., a thermal soft X-ray component plus a power-law component. Meanwhile, the fractional contribution of the power-law luminosity eta (eta = L-0.5-10 kev(power law)/L0.5-10 kev) varies with the X-ray luminosity L0.5-10 kev. In this paper, we systematically investigate the origin of such X-ray emission within the framework of the advection-dominated accretion flow (ADAF) around a weakly magnetized NS, in which the thermal soft X-ray component arises from the surface of the NS and the power-law component arises from the ADAF itself. We test the effects of the viscosity parameter alpha in the ADAF and thermalized parameter f(th) (describing the fraction of the ADAF energy released at the surface of the NS as thermal emission) on the relation of eta versus L0.5-10 kev. It is found that eta is nearly a constant (similar to zero) with L0.5-10 kev for different alpha with f(th) = 1, which is inconsistent with observations. Meanwhile, it is found that a change of f(th) can significantly change the relation of eta versus L0.5-10 kev. By comparing with a sample of non-pulsating NS-low mass X-ray binaries probably dominated by low-level accretion on to NSs, it is found that a small value of f(th) less than or similar to 0.1 is needed to match the observed range of eta greater than or similar to 10 per cent in the diagram of eta versus L0.5-10 kev. Finally, we argue that the small value of f(th) less than or similar to 0.1 implies that the radiative efficiency of NSs with an ADAF accretion may not be as high as the predicted result previously of epsilon similar to (M) over dot GM/R-not equal/(M) over dot c(2) similar to 0.2 despite the existence of the hard surface. |
| WOS关键词 | CEN X-4 ; BLACK-HOLES ; RADIATIVE EFFICIENCY ; SWIFT OBSERVATIONS ; THERMAL EMISSION ; SAX J1808.4-3658 ; DISK ACCRETION ; EXO 0748-676 ; AQL X-1 ; QUIESCENCE |
| 资助项目 | National Natural Science Foundation of China[11773037] ; National Natural Science Foundation of China[11673026] ; gravitational wave pilot B[XDB23040100] ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences[XDA15052100] ; National Program on Key Research and Development Project[2016YFA0400804] |
| WOS研究方向 | Astronomy & Astrophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000512329900048 |
| 出版者 | OXFORD UNIV PRESS |
| 资助机构 | National Natural Science Foundation of China ; National Natural Science Foundation of China ; gravitational wave pilot B ; gravitational wave pilot B ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences ; National Program on Key Research and Development Project ; National Program on Key Research and Development Project ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; gravitational wave pilot B ; gravitational wave pilot B ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences ; National Program on Key Research and Development Project ; National Program on Key Research and Development Project ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; gravitational wave pilot B ; gravitational wave pilot B ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences ; National Program on Key Research and Development Project ; National Program on Key Research and Development Project ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; gravitational wave pilot B ; gravitational wave pilot B ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences ; Strategic Pioneer Program on Space Science, Chinese Academy of Sciences ; National Program on Key Research and Development Project ; National Program on Key Research and Development Project |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/54186]  |
| 专题 | 中国科学院国家天文台 |
| 通讯作者 | Qiao, Erlin |
| 作者单位 | 1.Chinese Acad Sci, Natl Astron Observ, Key Lab Space Astron & Technol, Beijing 100101, Peoples R China 2.Univ Chinese Acad Sci, Sch Astron & Space Sci, 19A Yuquan Rd, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Qiao, Erlin,Liu, B. F.. A systematic study of the advection-dominated accretion flow for the origin of the X-ray emission in weakly magnetized low-level accreting neutron stars[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2020,492(1):615-627. |
| APA | Qiao, Erlin,&Liu, B. F..(2020).A systematic study of the advection-dominated accretion flow for the origin of the X-ray emission in weakly magnetized low-level accreting neutron stars.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,492(1),615-627. |
| MLA | Qiao, Erlin,et al."A systematic study of the advection-dominated accretion flow for the origin of the X-ray emission in weakly magnetized low-level accreting neutron stars".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 492.1(2020):615-627. |
入库方式： OAI收割
来源：国家天文台
浏览0
下载0
收藏0
其他版本
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。