Blazar中央黑洞的变化特征和质量估计

利用blazar的长期的光学和红外测光数据分析了其变化特性,并利用Jurkevich技术和分立相关函数(DCF)法在光学数据中寻找光变曲线中的周期性.发现了1.5至19yr范围的周期.利用短时间尺度来估计中央黑洞的质量,发现γ射线噪blazar的中心黑洞质量范围为(3.8～130)×10     

Estimating Black Hole Masses of AGNs using Ultraviolet Emission Line Properties

Based on measured broad line region sizes in the reverberation-mapping AGN sample, two new empirical relations are introduced to estimate the central black hole masses of radio-loud high-redshift (z > 0.5) AGNs. First, using the archival IUE/HST spectroscopy data at UV band for the reverberation-mapping objects, we obtained two new empirical relations between the BLR size and Mg II/C IV emission line luminosity. Secondly, using the newly determined black hole masses of the reverberation-mapping sample as calibration, we found two new relationships for determining the black hole mass with the full width at half maximum and the luminosity of Mg II/C IV line. We then apply the relations to estimate the black hole masses of the AGNs in the Large Bright Quasar Survey and a sample of radio-loud quasars. For the objects with small radio-loudness, the black hole mass estimated using the RBLR-LMgII/C IV relation is consistent with that from the RBLR-L3000 (?)/1350(?) relation. For radio-loud AGNs, however, the mass estimated from the RBLR-LMgII/CIV relation is sys- tematically lower than that from the continuum luminosity L3000(?)/1350(?). Because jets could have significant contributions to the UV/optical continuum luminosity of radio-loud AGNs, we emphasize once again that for radio-loud AGNs, the emission line luminosity may be a better tracer of the ionizing luminosity than the continuum luminosity, so that the relations between the BLR size and UV emission line luminosities should be used to estimate the black hole masses of high redshift radio-loud AGNs.     

Blazar黑洞质量

与吸积率和爱丁顿吸积率的比率一道,黑洞质量也是活动星系核的一个基本参数。我们采用谢光中等的新方法去估计了21个blazar样本的黑洞质量(MH),同时运用了MBH-σ相关分析方法来估计同一个blazar样本的黑洞质量(Mσ),通过对两种不同方法所得样本黑洞质量的比较,我们发现(1)MH系统的小于Mσ,但是对于大多数blazar样本来说Mσ和MH之间的差别很小;(2)在Mσ和MH之间存在着一个有意义的相关性,相关系数为r=0.832,p≤1.0×10-4。以上述的这些性质和活动星系核标准模型为基础,我们证明了这两种方法所得的黑洞质量Mσ和MH之间的系统差异是因为Mσ描述的是宽发射线区(r≤rb)的黑洞质量,而MH描述的是黑洞周围在最内层轨道附近的连续发射区的质量。这就是说Mσ应该是被过度估计了。由Mσ和中心黑洞质量MH*的关系,我们再次计算中心黑洞质量MH*,并且发现中心黑洞质量MH*和MH几乎是相同的。     

The Black Hole Masses and Radio Characteristics of Radio Quasars

In this paper, we collect the redshift, bolometric luminosity, the full- width at half maximum of the H_β emission line, the monochromatic luminosity at 5100 Å and the radio loudness for the sample of 117 quasars, including 20 radio-quiet quasars (RQQs) and 97 radio-loud quasars (RLQs). With the reverberation mapping method we calculate the black hole mass and Eddington ratio for this sample, as well as the radio luminosity from the total 5 GHz ?ux density. By analyzing the correlations among them, we obtain the following conclusions: (1) The black hole mass has weak correlations with the bolometric luminosity, radio loudness and radio luminosity for the RQQs, and has strong correlations with the bolometric luminosity, radio loudness and radio luminosity for the RLQs; (2) For the RQQs, the bolometric luminosity has weak correlations with the radio luminosity and 5 100 Å monochromatic luminosity, and for the RLQs, the bolometric luminosity has strong correlations with the radio luminosity and 5 100 Å monochromatic luminosity; (3) The RQQs and RLQs differ in the distributions of the black hole mass, emission line width and Eddington ratio. Based on these results, we suggest: the difference of emission line width between RQQs and RLQs is probably caused by the difference of black hole mass; the fundamental difference between RQQs and RLQs is caused by the difference of their intrinsic physical nature; the black hole mass, black hole spin, Eddington ratio, and host galaxy morphology are the important parameters to explain the origin of radio loudness and the double-peaked distribution; and the radio jet is closely related with the accretion rate of disk.     

Estimation of Black Hole Masses from Steep Spectrum Radio Quasars

In this work, we employ a sample of 185 steep-spectrum radio quasars (SSRQs) to estimate their black hole masses from broad emission lines. Our black hole masses are compared with the virial black hole masses estimated by Shen (2010). We find that there is a large deviation between the two kinds of values if the black hole masses are estimated from broad emission line of CIV. However, both values are in agreement if the black hole masses are estimated from broad emission line of MgII or Hβ.     

耀变体亮温度与黑洞喷流能量的相关性讨论

耀变体(Blazars)的亮温度与黑洞喷流能量和吸积率有重要关系.搜集了53个耀变体源样本,包括22个蝎虎天体(BL Lacs)和31个平谱射电类星体(Flat Spectrum Radio Quasars,FSRQs),研究了耀变体亮温度与黑洞喷流能量的分布,并对子类中亮温度与黑洞喷流能量的相关性进行了讨论.研究结果...     

Black Hole Dynamic Potentials

In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of thermodynamics. Nine fundamental black hole dynamical relations have been developed akin to the four fundamental thermodynamic relations of Maxwell. The specific heats C _??,?? and C _J,Q have been defined. For a black hole, these quantities are negative. The ??dA equation has been obtained as an application of these fundamental relations. Time reversible processes observing constancy of surface gravity are considered and an equation connecting the internal energy of the black hole E, the additional available energy defined as the first free energy function K, and the surface gravity ??, has been obtained. Finally as a further application of the fundamental relations, it has been proved for a homogeneous gravitational field in black hole space times or a de Sitter black hole that $C_{\Omega ,\Phi } -C_{J,Q} =\kappa \left[ {\left( {\frac{\partial J}{\partial \kappa }} \right)_{\Omega ,\Phi } \left( {\frac{\partial \Omega }{\partial \kappa }} \right)_{J,Q} +\left( {\frac{\partial Q}{\partial \kappa }} \right)_{\Omega ,\Phi } \left( {\frac{\partial \Phi }{\partial \kappa }} \right)_{J,Q} } \right]$ . This is dubbed as the homogeneous fluid approximation in context of the black holes.     

On the Neutron Star/Black Hole Mass Gap and Black Hole Searches

Mass distribution of black holes in low-mass X-ray binaries previously suggested the existence of a ～2–5 M⊙mass gap between the most massive neutron stars and the least massive black holes, while some recent evidence appears to support that this mass gap is being populated. Whether there is a mass gap or not can potentially shed light on the physics of supernova explosions that form neutron stars and black holes, although significant mass accretion of neutron stars including binary mergers may l...     

The Formation of Black Hole Binaries

A peak exists in the distribution of observed black hole masses and no satisfactory explanation has been forthcoming so far. Here, we attempt an interpretation. We first establish a link between the helium core mass and the initial black hole mass, based on the result of 2-dimensional simulation of stellar core collapse by Fryer et al. Then the helium core masses are computed by using the PPE stellar evolution code, and the distribution of initial black hole masses for black hole binaries in stellar populations II and I is obtained. These are then compared with observations.     

The Density and Masses of Obscured Black Holes

Recent Chandra and XMM-Newton surveys have uncovered a large fraction of the obscured AGN responsible of the hard X-ray background. One of the most intriguing results of extensive programs of follow-up observations concerns the optical and near-infrared properties of the hard X-ray sources counterparts. More specifically, for a significant fraction of hard X-ray obscured sources the AGN responsible of the high X-ray luminosity remains elusive over a wide range of wavelengths from soft X-rays to near-infrared. This very observational result opens the possibility to investigate the host of bright obscured quasars in some detail. Here we briefly report on some preliminar results obtained for a small sample of elusive AGN in the HELLAS2XMM survey.     

The Evolution of Black Hole States

We discuss the evolution of black hole transients on the basis of a few systems that were intensively observed with the Rossi X-ray Timing Explorer (rxte). We focus on the global evolution and the observed state transitions. Rather than giving a numerical recipe for classifying observations, we try to identify times during outbursts at which clear changes occur in the X-ray variability, X-ray spectral, or multi-wavelength properties.     

黑洞吸积的双模式特征

黑洞吸积必定是跨声速的。对于静态、绝热吸积流,比能量E、比角动量L和质量吸积率M都是空间的常量。跨声速解的非奇异条件,F(E,L,M)=0,使独立参数减为只有两个。对于一对给定的E和L的符合条件E_c>E>E_(Barr)的值(这里E_c是一临界值,E_(Barr)是引力和离心力的联合势垒),上述非奇异条件给出两个不同的吸积率值,对应着两个不同的吸积流声速点位置。然而,物理上合理的整体解却是唯一的,它总是使两个吸积率值中之较小者得到实现。 对于一个不转动的黑洞,吸积以两种模式之一进行。一是类球吸积或称Bondi吸积,角动量的影响和相对论效应均微不足道;另一是盘吸积,这两个因素起决定性作用。两种模式之间的转换是基于声速点位置的间断性跳跃,而这种跳跃是由吸积流参数(例如角动量)的连续变化所引发。Bondi吸积可称为高态而盘吸积为低态,因为前者总对应着较高的吸积率。 随时间变化的吸积流很可能在这两种模式之间来回振荡,呈现出周期性或准周期性或无规则行为。这可以用来解释天鹅座X-1和若干活动星系核的光变现象,从而为黑洞的存在提供有力的观测依据。     

Black Hole in a Radiation-Dominated Universe

We study a black hole in an expanding Universe during the radiation-dominated stage. In particular, such a black hole may be of the primordial origin. In the case when the black hole radius is much smaller than the cosmological horizon, we found a self-consistent solution for the metric and the matter distribution and its velocity far from the black hole. At distances much smaller than the cosmological horizon our solution coincides with the previously obtained solution for quasi-stationary accretion. Our results can be applied, in particular, for the formation of dark matter density spikes around primordial black holes, and for the evolution of dark matter clumps during the radiation-dominated stage.     

Black Hole Mergers in the Universe

We present the first grating-resolution X-ray spectra of the Seyfert 1 galaxy NGC 3783, obtained with the High Energy Transmission Grating Spectrometer on the Chandra X-Ray Observatory. These spectra reveal many narrow absorption lines from the H-like and He-like ions of O, Ne, Mg, Si, S, and Ar as well as Fe xvii-Fe xxi L-shell lines. We have also identified several weak emission lines, mainly from O and Ne. The absorption lines are blueshifted by a mean velocity of approximately 440+/-200 km s-1 and are not resolved, indicating a velocity dispersion within the absorbing gas of a few hundred kilometers per second or less. We measure the lines' equivalent widths and compare them with the predictions of photoionization models. The best-fitting model has a microturbulence velocity of 150 km s-1 and a hydrogen column density of 1.3x1022 cm-2. The measured blueshifts and inferred velocity dispersions of the X-ray absorption lines are consistent with those of the strongest UV absorption lines observed in this object. However, simple models that propose to strictly unify the X-ray and UV absorbers have difficulty explaining simultaneously the X-ray and UV absorption-line strengths.     

Black Hole Hyperaccretion and Gamma-ray Burststwo

Black hole hyperaccretion model is one of the potential candidates for the central engine of gamma-ray bursts. Combined with the complicated explosion phenomena including gamma-ray bursts, gravitational waves, and their electromagnetic counterparts, the results of a series of theoretical studies on this model are briefly reviewed in this paper. At the same time, as the research tools for the subsequent studies on gamma-ray bursts, some important conclusions and formulas are presented.     

The Masses of Black Holes in X-ray Binary Systems

Recent results concerning the determination of the masses of eleven black hole candidates in X-ray binary systems are summarized. It is very significant that there are no pulsars or X-ray bursters of the first kind among the eleven known massive (mx > 3M) X-ray sources in close binary systems.     

黑洞吸积盘的数值模拟

近十几年来,人们已经对吸积盘进行了深入的研究。前人很多工作都是解析工作。虽然解析工作能够简单明了地揭示盘的许多重要性质,但吸积盘的很多重要性质(例如:对流和外流)没有办法通过解析工作进行深入的研究。数值模拟是研究天体物理的重要手段。近十年来,随着计算机技术的迅速发展,数值模拟在天体物理研究中扮演了越来越重要的角色。本论文主要用数值模拟的手段研究吸积盘中一些重要的物理过程。     

Variability of Blazars

Variability is one of the characteristics of blazars. The rapid variability is superposed on the long term variation. In this work, the variability on different time scales, such as intra-day (IDV), short-term (STV) and long-term (LTV) variations are presented for some sources. We also presented our own observations of some selected objects, for which the historical data were compiled for periodicity analysis using several methods. The parameters of the binary black hole system OJ 287 are determined.     

Black Hole Spin in AGN and GBHCs

We discuss constraints on black hole spin and spin-related astrophysics as derived from X-ray spectroscopy. After a brief discussion about the robustness with which X-ray spectroscopy can be used to probe strong gravity, we summarize how these techniques can constrain black hole spin. In particular, we highlight XMM-Newton studies of the Seyfert galaxy MCG-6-30-15 and the stellar-mass black hole GX 339-4. The broad X-ray iron line profile, together with reasonable and general astrophysical assumptions, allow a non-rotating black hole to be rejected in both of these sources. If we make the stronger assertion of no emission from within the innermost stable circular orbit, the MCG-6-30-15 data constrain the dimensionless spin parameter to be a > 0.93. Furthermore, these XMM-Newton data are already providing evidence for exotic spin-related astrophysics in the central regions of this object. We conclude with a discussion of the impact that Constellation-X will have on the study of strong gravity and black hole spin.