M 87大尺度喷流的多波段研究

射电星系M87的大尺度喷流在射电、光学和X波段都已经具备高分辨率的成像观测和频谱观测。其各个节点的宽波段连续谱目前被认为是同步辐射主导的。文章采用相对论性电子同步辐射的Kardashev-Pacholczyk模型,对各节点的多波段连续谱进行了独立的最佳拟和,从而得到相应的多普勒因子。此外进一步结合各节点的视超光速运动的观测数据,导出了不同节点整体运动的Lorentz因子和对观测者的视角。计算结果表明,M87的大尺度喷流具有一定程度的弯曲,其整体动力学行为是减速的。

Study of Large Scale Jet in M87 at the Multi-Wavebands

The large scale jet of the radio galaxy M87 has been observed in high resolution at radio and optical wavelengths as well as X-ray band, the spectra of the knots are commonly believed to be generated from synchrotron emission. We study spectra of the knots in the jet at the multi-wavebands by using Kardashev-Packolczyk radiation model, and obtain the corresponding Doppler factor.Combined with superluminal motion, we derive the Lorentz factor and the angle to the line of sight for individual knots. Our results show that M87 has a slightly bend as well as a moderated relativistic jet.We also find that the bulk velocity of its jet decelerates as it flows down.