ON THE RADIO DICHOTOMY OF ACTIVE GALACTIC NUCLEI
文献类型：期刊论文
| 作者 | Cao, Xinwu1,2 |
| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2016-12-10 |
| 卷号 | 833期号:1页码:6 |
| ISSN号 | 0004-637X |
| 关键词 | accretion, accretion disks black hole physics galaxies: active galaxies: jets magnetic fields |
| DOI | 10.3847/1538-4357/833/1/30 |
| 通讯作者 | Cao, Xinwu(cxw@shao.ac.cn) |
| 英文摘要 | It is still a mystery why only a small fraction of active galactic nuclei (AGNs) contain relativistic jets. A strong magnetic field is a necessary ingredient for jet formation, however, the advection of the external field in a geometrically thin disk is inefficient. Gas with a small angular velocity may fall from the Bondi radius R-B nearly freely to the circularization radius R-c, and a thin accretion disk is formed within R-c. We suggest that the external magnetic field is substantially enhanced in this region, and the magnetic field at R-c can be sufficiently strong to drive outflows from the disk if the angular velocity of the gas is low at R-B. The magnetic field is efficiently dragged in the disk, because most angular momentum of the disk is removed by the outflows that lead to a significantly high radial velocity. The strong magnetic field formed in this way may accelerate jets in the region near the black hole, either by the Blandford-Payne or/and Blandford-Znajek mechanisms. We suggest that the radio dichotomy of AGNs predominantly originates from the angular velocity of the circumnuclear gas. An AGN will appear as a radio-loud (RL) one if the angular velocity of the circumnuclear gas is lower than a critical value at the Bondi radius, otherwise, it will appear as a radio-quiet (RQ) AGN. This is supported by the observations that RL nuclei are invariably hosted by core galaxies. Our model suggests that the mass growth of the black holes in RL quasars is much faster than that in RQ quasars with the same luminosity, which is consistent with the fact that the massive black holes in RL quasars are systematically a few times heavier than those in their RQ counterparts. |
| WOS关键词 | BLACK-HOLE SPIN ; HOST GALAXY/AGN CONNECTION ; EARLY-TYPE GALAXIES ; ADVECTION-DOMINATED ACCRETION ; MAGNETIC PRANDTL NUMBER ; VERTICAL STRUCTURE ; JET POWER ; DIFFUSION-COEFFICIENTS ; BRIGHTNESS PROFILES ; COLLAPSING STAR |
| WOS研究方向 | Astronomy & Astrophysics |
| 语种 | 英语 |
| 出版者 | IOP PUBLISHING LTD |
| WOS记录号 | WOS:000390556900003 |
| 源URL | [http://libir.pmo.ac.cn/handle/332002/23377]  |
| 专题 | 中国科学院紫金山天文台 |
| 通讯作者 | Cao, Xinwu |
| 作者单位 | 1.Chinese Acad Sci, Shanghai Astron Observ, SHAO XMU Joint Ctr Astrophys, 80 Nandan Rd, Shanghai 200030, Shanghai, Peoples R China 2.Chinese Acad Sci, Key Lab Radio Astron, Nanjing 210008, Jiangsu, Peoples R China |
| 推荐引用方式 GB/T 7714 | Cao, Xinwu. ON THE RADIO DICHOTOMY OF ACTIVE GALACTIC NUCLEI[J]. ASTROPHYSICAL JOURNAL,2016,833(1):6. |
| APA | Cao, Xinwu.(2016).ON THE RADIO DICHOTOMY OF ACTIVE GALACTIC NUCLEI.ASTROPHYSICAL JOURNAL,833(1),6. |
| MLA | Cao, Xinwu."ON THE RADIO DICHOTOMY OF ACTIVE GALACTIC NUCLEI".ASTROPHYSICAL JOURNAL 833.1(2016):6. |
入库方式： OAI收割
来源：紫金山天文台
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