标题： 超光速运动和耀变体喷流中的相对论性束射 显示英文标题

标题： Superluminal Motion and Relativistic Beaming in Blazar Jets

摘要： 高分辨率射电观测仍然是研究围绕大质量黑洞吸积的射电喷流形成和演化的最直接方法。 我们报告了为期七年的VLBA观测计划的初步结果，以了解耀变体中相对论性束流的性质以及大质量黑洞周围的环境。 大多数耀变体显示出从活跃核心向外流动的明显现象。 然而，在少数天体中，运动看起来是向内的，这很可能是由于弯曲轨迹的投影，该轨迹弯向视线方向。 喷流特征的明显运动并不总是沿着将特征与核心分开的方向，而在一些情况下，我们观察到当特征沿喷流流动时，其方向和速度发生了明显的变化。 在其他天体中，运动似乎遵循简单的弹道轨迹。 我们发现流量密度变化的时间尺度与明显组分速度之间没有简单的关系。 显示英文摘要

摘要： High resolution radio observations remain the most direct way to study the formation and evolution of radio jets associated with the accretion onto massive black holes. We report preliminary results of our seven year VLBA observational program to understand the nature of relativistic beaming in blazars and the surrounding environment of massive black holes. Most blazars show an apparent outward flow away from an active core. However, in a few sources the motion appears inward, most likely the result of projection of a curved trajectory which bends back toward along the line of sight. The apparent motion of jet features is not always oriented along the direction separating the feature from the core, and in a few cases we have observed a clear change in the direction and velocity of a feature as it flows along the jet. In other sources, the motion appears to follow a simple ballistic trajectory. We find no simple relation between the time scales of flux density changes and apparent component velocities.