KMS of Xinjiang Astronomical Observatory, CAS
| 活动星系核喷流和吸积盘的相关性研究 | |
| Alternative Title | Correlation between Jet and Accretion Disk of AGN |
韩振华
| |
| Subtype | 博士 |
| Thesis Advisor | 刘祥 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 天体物理 |
| Keyword | 活动星系核星系核 黑洞 吸积 喷流 功率 吸积盘光度 盘光度 相关性 |
| Abstract | 本文主要对活动星系核的喷流-吸积盘的相关性问题进行了研究，着重研究了不同类型活动星系核样本的喷流功率、吸积盘光度、射电噪度、黑洞质量以及质量吸积率等物理量之间的相关关系，这些物理量可以反映活动星系核黑洞吸积和射电活动性之间相互作用和共同演化的一些特征。结合这种相关性的统计分析本文讨论了活动星系核喷流发生的可能机制，讨论了活动星系核射电喷流和黑洞吸积盘之间的相关性，并对活动星系核的“黑洞活动的基本面关系”提出了一些不同的解释。 首先，本文从黑洞吸积物理的基本假设出发，利用牛顿近似方法提出了一种纯吸积情况下的喷流-吸积盘相关的定量数学表述。该数学模型表明纯吸积情况下，活动星系的射电喷流功率和吸积盘光度之间满足线性关系。在进一步研究射电喷流功率和吸积盘光度之间、射电噪度和吸积盘光度之间的幂律谱相关性后，本文得到了相关后幂律谱指数之间的定量关系即ρ=（7/6）μ-1，这能够很好地解释不同活动星系样本之间喷流和吸积盘相关性的差异性表现，即幂律谱指数的样本μ<6/7的样本，射电噪度和吸积盘光度之间存在反相关，幂律谱指数μ>6/7的样本，射电噪度和吸积盘光度之间存在正相关。结合不同类型样本的统计分析，发现对于红移z<0.5、艾丁顿比或质量吸积率λ< 0.1的塞弗特星系、窄线射电星系样本来说，拟合后的幂律谱指数结果明显小于1，相反地对于高红移类星体幂律谱指数的拟合结果通常为μ≥1。本文也讨论了相比于黑洞自旋的贡献而言，对于高红移的FRII 型类星体其射电喷流功率很大程度上是由吸积盘吸积主导的。 其次，本文结合更多类型的样本进行了统计拟合和相关性分析，发现对于不同的活动星系核以及黑洞X 射线双星样本而言，射电喷流功率Lj和吸积盘光度Ldisk之间表现为正相关，但相关斜率（幂律谱指数）各不相同。从结果来看，对于不同类型的样本而言，其喷流-吸积盘相关的表现是多样化的，因此本文对所谓的“黑洞活动的基本面关系”进行了再讨论，本文认为原先的“黑洞活动的基本面关系”并不具备内禀的物理意义，很难用完全单一的相关关系对本文分析的多样化相关结果进行物理解释。但是对于不同类型的样本，本文也发现其喷流-吸积盘的相关性大体表现出两种不同类型的变化趋势，一类幂律谱指数相关后斜率为μ≥1（Lj∝L_disk^μ），另一类相关后斜率变化为μ~0.3−0.6。从这个层面说，对于活动星系核和黑洞X射线双星样本而言，本文认为仍然可以用基本面关系来描述样本的黑洞吸积和射电活动的相关性。从本征内禀的物理层面上讨论，本文认为更合适的基本面关系表述主要区分为两种类型，一种是喷流-吸积盘陡谱相关的样本，其喷流有可能是黑洞吸积作用主导发生的，另一种喷流-吸积盘平谱相关的样本，其喷流有可能由混合机制来主导发生，这种混合机制来源于黑洞吸积和黑洞自旋的共同作用。当样本的质量吸积率较低时需要黑洞自旋的共同作用来产生射电喷流，当样本的质量吸积率高到一定程度就有可能抑制黑洞自旋激发喷流的作用，同时仅靠黑洞吸积自身就能产生一个强有力的喷流。 最后，本文分析了一个包含FRII型射电星系和类星体的3CRR样本，计算了样本的射电光度，对样本的窄发射线[OII]、[OIII]进行了相关性分析，通过窄发射线的交叉相关计算了样本的吸积盘光度。本文进一步考察了3CRR样本中FRII型射电星系和类星体的红移分布；结合提出的喷流-吸积盘相关模型，分析了该样本的射电光度和吸积盘光度的相关性，二者的射电光度和吸积盘光度之间都存在较强相关，类星体的相关斜率要比FRII射电星系更陡一些，说明类星体的吸积盘辐射效率更高一些。但二者相关的幂律谱指数在 0.3~0.6区间范围内，意味着这两个类型的射电活动性特征属于平谱相关的类型，可能说明这两个类型的喷流可能起源于黑洞吸积和黑洞自旋共同作用的混合机制，当然也和样本的大小有一定关系。同时样本中RII射电星系包含少量的低激发射电星系，这是一类特殊的子型，该子型的红移分布、射电活动性与高激发射电星系和类星体之间大有不同，这需要更大更完备的样本来进一步研究。 |
| Other Abstract | In this thesis, we present the studies of the jet-disk connection in Active Galactic Nuclei (AGN). we mainly focus on the research of the correlations between the physical quantities of different types of AGN such as radio jet power, disk luminosity, radio loudness, BH mass and mass accretion rate etc., for that the correlations can describe the interaction and co-evolution of the central engine and radio activities in AGN. Firstly, we propose a jet-disk connection model by using Newtonian approximation from basic assumptions of black hole accretion physics. The model assumes that the jet power is the disk accretion produced, which is expected to be linearly proportional to the product of the Eddington ratio and BH mass. By further studies of the correlation of power-law index between radio jet power, radio loudness and disk luminosity, we acquire a simple quantitative relation: ρ=（7/6）μ-1. The relation can well illustrates the diverse statistic results of the jet-disk connection for different types of AGN. Radio jet power and bolometric disk luminosity show a positive correlation in general but not linearly for different samples, and the power-law index μ is so different which leads a positive or negative correlation between radio loudness and disk luminosity. The power-law indices are significantly less than unity for redshift z< 0.5 and relatively low accretion (λ<0.1) AGN in radio galaxies and Seyfert galaxies. On the contrary, for high-z quasars which often shows the slope:μ≥1.We discuss that the jet power of the high-z FRⅡquasars is likely dominated by the accretion disk rather than by the BH spin. Secondly, more types of AGN and BHXBs have been analyzed statistically and fitted linearly on jet-disk correlations by before-mentioned model. It is obviously not possible to unify the different slopes with a single power-law slope in our analysis, and the diverse behaviors of the correlation between radio jet power and disk luminosity indicate that using a general correlation to illustrate the black hole activity in so-called ‘the fundamental plane’ is far from enough and not intrinsic in physics. ‘The physical fundamental plane of black hole activity’ discussed in this thesis actually refers to the correlation between the jet power and disk luminosity or equivalently to the correlation between the jet power, Eddington ratio and BH mass, rather than the jet power, disk luminosity and BH mass. The statistic and fitting results appear two kinds of correlation slopes for both BHXBs and AGN: the power-law correlation index is steep (μ~1.0−1.4) for radio loud quasars and the ‘outliers’ track of BHXBs, and it is flatter (μ~0.3−0.6) for radio loud galaxies and the standard track of BHXBs. In view of the intrinsic analysis, we still have a fundamental plane of black hole activity for BHXBs and AGN with the two kinds of correlation indices: the steep-index subgroups (μ~1.0−1.4) are mostly at higher accretion rates and the jets could be dominated by the accretion of BH. The fatter-index subgroups are at relatively low accretion rates and the jets would be a hybrid production by the accretion and spin of BH. A minimum accretion rate is required for the black hole spin to create a jet, and a high accretion rate would be able to suppress the spin-induced jet and instead to form a more powerful jet by the accretion itself. Finally, we examine the consistency of the jet-disk connection with our model in the 3CRR sample. We calculated radio luminosity and disk luminosity of the sample, and the redshift distributions of FRII radio galaxies and quasars in the 3CRR sample have been inspected. The correlations of radio luminosity and disk luminosity have been analyzed by our jet-disk connection model, and we find that quasars have steeper power law index than FRII galaxies. The power-law index of μ the two types are in the range of 0.3 to 0.6, therefore FRII galaxies and quasars in the 3CRR sample belong to the flatter-index subgroups in our ‘physical fundamental plane’, and the jet of these two types could be likely induced by hybrid effect of the accretion and spin of BH. It is notable that FRII radio galaxies in the 3CRR sample include a small number of low-excitation galaxies(LEGs), and the redshift distribution, radio activity, jet-disk connection of LEGs are very distinguishing from the high-excitation galaxies and quasars, thus it deserves a further study by using a larger and more complete sample. |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/1714 |
| Collection | 研究生学位论文 射电天文研究室 |
| Affiliation | 中国科学院新疆天文台 |
| Recommended Citation GB/T 7714 | 韩振华. 活动星系核喷流和吸积盘的相关性研究[D]. 北京. 中国科学院大学,2016. |
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| 韩振华-学位论文.pdf（3360KB） | 学位论文 | 暂不开放 | CC BY-NC-SA | Application Full Text | ||
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