相对论喷束模型中表现速度计算的修正

在相对论喷束模型中，假设源的核在观测者静止坐标系中不动的前提下，推出了现在已得到广泛承认和采用的计算相对论等离子团横向视速度的公式．随着观测精度的提高，对核固定不动的假设提出了怀疑，认为有必要重新估价表现横向速度公式的正确性，并在更普遍的框架下，找出该公式的修正形式．本文试图对几种根据目前对射电源一般结构认识提出的模型，初步探讨这种修正的可行性．     

Model of VLBI observation within the relativistic framework

In this paper we derive the post-newtonian expressions for the VLBI time delay and gravitational delay in the barycentric coordinate system of the solar system. We discuss the effect of the various bodies and their range of action. From the transformation between the barycentric and the geocentric systems we then give the VLBI observational model in the geocentric system. Our final results are given by formula (16) for the gravitational delay and by formula (25) for the VLBI time delay.     

An Addendum to the Damour and Deruelle's Solution of the Post-Newtonian Two-Body Problem

A complement to the the analytical solution given by Damour and Deruelle (D&D) in order to solve the differential equations that describe the conic-like and rectilinear post-Newtonian two-body problem is presented. We show the geometric relation between the eccentric and true anomalies for the elliptic-like and hyperbolic-like cases and expressions for their velocities are obtained. A post-Newtonian version of the Lambert's theorem is shown. This revised version was published online in July 2006 with corrections to the Cover Date.     

致密射电变源中的快速流量变化——壳层情形

本文讨论等离子体壳层在双重相对论效应下(即膨胀和整体运动都是相对论性的条件下)的同步辐射的快速变化。表明这类壳层模型可以相当容易地解释观测到的视超光速流量变化。文中特别讨论了这类模型在获得很大的多普勒因子(δ50),从而在解释某些厘米波变源的特别快的流量变化(时间尺度～1—10天)上的意义。     

The Wilkinson Microwave Anisotropy Probe (WMAP) confirmed the model of our observed relativistic universe

The Wilkinson Microwave Anisotropy Probe (WMAP) confirmed the model of flat expansive homogeneous and isotropic relativistic universe, which describes the properties of our observed flat expansive homogeneous and isotropic relativistic Universe in the first (linear, Newtonian or classical-mechanical) approximation.     

Superluminal Motion and Polarization in Blazars

A relativistic beaming model has been successfully used to explain the observed properties of active galactic nuclei (AGNs). In this model there are two emission components, a boosted one and an unbeamed one, shown up in the radio band as the core and lobe components. The luminosity ratio of the core to the lobe is denned as the core-dominance parameter (R = LCore/LLobe). The de-beamed radio luminosity (Ldbjet) in the jet is assumed to be proportional to the unbeamedluminosity (Lub) in the co-moving frame, i.e., f = Ldbjet/Lub, and f is determined in ourprevious paper. We further discuss the relationship between BL Lacertae objects (BLs) and flat spectrum radio quasars (FSRQs), which are subclasses of blazars with different degrees of polarization, using the calculated values of the ratio f for a sample of superluminal blazars. We found 1) that the BLs show smaller averaged Doppler factors and Lorentz factors, larger viewing angles and higher core-dominance parameters than do the FSRQs, and 2) that in th     

A relativistic model of the movement of apparent superluminal radio sources

Based on the relativistic model of the apparent superluminal motion and under the condition that the center of mass of a superluminal radio source remains in motion relative to the observer, the equation of the apparent velocity between nucleus and component is derived. Assuming that the directions of jet and movement of superluminal radio source are opposite, then, supposing that the velocities of nucleus and components of SLS are equal and the nucleus is fixed, the equations of real velocity are respectively derived. With the data of V_app and θ substituted in the equation of real velocity, the velocity of the components of SLS is obtained. Comparing the real velocity with the velocity of Hubble redshift of SLS, it is concluded that the movement of SLS has no influence on the velocity of components.     

E2-transition probabilities for NiXVIII

Accurate theoretical data for the transition probabilities are highly demanding in astrophysics and in the study of plasma in astrophysical objects and fusion devices. Na-like highly stripped ions of iron group, specially NiXVIII is very important in this respect. A highly improved basis in a relativistic many-body coupled-cluster method (CCM) to include correlation properly is employed to calculate excitation energies, the electric quadrupole (E2) transition line strengths and transition probabilities for NiXVIII. The effect of correlation is studied thoroughly. The present improved data for different atomic/ionic properties are compared with the available theoretical and/or experimental data and they are in agreement. Some E2 transition data are reported for the first time. This revised version was published online in July 2006 with corrections to the Cover Date.     

黑洞的搜寻和证认(I):现状

简要介绍有关黑洞的理论及其表现形式,详细综述在星系中心及X射线双星中搜寻和证认黑洞的原理、方法及现状．在星系层次,除活动星系核中心可能存在的黑洞外,在邻近星系中已找到至少11个黑洞候选者,但观测所及的最小尺度仍比黑洞视界高几个量级。在恒星层次,利用动力学判据,人们己在大质量X射线双星和软X射线暂现源中找到至少10个强候选者,并利用辐射判据找到更多的候选者,但目前仍然没有找到黑洞双星区别于中子星双星的决定性判据．所有这些说明,迄今尚未找到充足的证据证明黑洞的存在。     

Black hole at the center of the globular cluster M15: Estimation of the mass and specific angular momentum

Using the technique of determining the sum of the masses of double stars, we have estimated the mass of the central object in the globular cluster M15. The radial velocities of stars at distances up to 1″ from the cluster center have been used. The parameters of circular orbits and the space velocities of 11 selected field stars relative to the cluster center have been determined from the calculated velocity dispersions with respect to the mean radial velocity. Based on the mean space velocity V, 14 km s^?1, and using the energy integral, we have estimated the mass of the central object to be within the range (1?9) × 10³ M _⊙. We have estimated the kinetic power of the outflow of matter from the region surrounding the black hole in M15 and the specific angular momentum of the black hole.