非均匀喷流模型与射电强活动星系核相对论性喷流研究

Inhomogeneous Jet Model and Research of Radio Loud Active Galactic Nuclei Relativistic Jet

在非均匀锥形喷流模型中,电子密度、磁场强度随着到喷流顶点的距离呈幂率分布。该模型能成功解释活动星系核喷流核心区域的平谱射电辐射,但已有的模型计算只适用于喷流运动方向与视线夹角很大的情况。该文给出了适用于任何视角情况的非均匀锥形喷流辐射计算公式,并利用数值计算方法计算了喷流的辐射谱。普遍认为BL Lac天体中喷流的运动方向与视线夹角很小,我们利用非均匀喷流模型拟合了3个BL Lac天体的射电观测谱,确定了它们喷流中电子密度,磁场强度等物理参数。我们的研究表明观测辐射谱拐折频率确定出锥形喷流离黑洞最近距离,对于这3个BL Lac天体,我们发现它们的锥形喷流离黑洞最近距离约为:Schwarzschild半径。

Konigl proposed an inhomogeneous jet model, in which the jet is assumed to have a conical geometry, that is, the velocity with which the jet is expanding sideways, is constant.We reconsider this jet model with assumptions and simplifications as few as possible and including more detailed considerations such as the difference of Doppler factor of each section of jet and the small viewing angle cases in BL Lacertae objects. We then apply our model to three BL Lacertae objects, fitted their spectrum energy distribution and derived the physical parameters of jets. We also calculate the kinetic energy and magnetic energy in jets of these three BL Lacertae objects and found that at pc scale the kinetic power dominant over magnetic power,indicating that the effective transfer efficiency from magnetic energy to kinetic energy