Variability of the Intensity, Structure, and Magnetic Field in Compact Blazar Jets

AST98-02941马歇尔尽管在探索类星体的本质方面已经取得了很大的进展，但现在对它们的了解还只有一部分。与类星体相关的能量现象被认为是由位于宿主星系中心的大质量黑洞的吸积提供动力的。燃料将是穿过银河系核心的星际气体，可能是与另一个星系相遇的结果。吸积气体的角动量使其形成一个围绕黑洞的差动旋转圆盘。在其中一些天体中--尤其是那些位于椭圆星系中心的天体--磁化的极端相对论等离子体喷流沿着圆盘的旋转轴以接近光速的速度向外流动。马歇尔博士正在研究在一些类星体中观察到的具有高度可变非热辐射的射电喷流的性质。这些对象是称为blazar的类的一部分。马舍尔博士正在比较真实喷流的高分辨率高频无线电图像和通过流体力学计算获得的模拟喷流图像。观测将跟踪新的结沿着喷流传播(大约每月一次从核心喷出)。还探讨了核心本身的性质，以及磁场的结构。***

AST 98-02941 Marscher Although much progress has been made in exploring the nature of quasars, they are now only partly understood. The energetic phenomena associated with quasars are thought to be powered by accretion only massive black holes lying at the centers of the host galaxies. The fuel would be interstellar gas that passes through the nucleus of the galaxy, probably as a result of an encounter with another galaxy. The angular momentum of the accreting gas causes it to form a differentially rotating disk surrounding a black hole. In some of these objects - preferentially those that lie at the centers of elliptical galaxies - jets of magnetized ultrarelativistic plasma flow outward at speeds near that of light along the rotation axis of the disk. Dr. Marscher is studying the nature of the radio jets with highly variable nonthermal radiation that are observed in some quasars. These objects are part of the class known as Blazars. Dr. Marscher is comparing high-resolution, high-frequency radio images of actual jets with images of simulated jets obtained through hydrodynamic calculations. The observations will follow propagation of new knots down the jets (ejected roughly monthly from the core). The nature of the core itself is also explored, and the structure of the magnetic field. ***