AI 中文总结
通过二维和三维相对论磁流体动力学模拟，探究分层环境介质中相对论磁化喷流的演化，推导扭结稳定性判据，计算多波段发射图，发现不同环境压力下喷流形态及辐射特征的差异。
AI 中文摘要
相对论射电星系喷流通常被分为FR I和FR II两类形态，其中FR I喷流具有较低的射电光度和边缘变暗的形态，表明它们在亚千秒差距到千秒差距尺度上会发生显著的减速和瓦解，常形成湍流且 plume-like（ plume状）的形态。本研究使用二维和三维相对论磁流体动力学模拟，结合多种环境轮廓，探究分层环境介质中相对论磁化喷流的演化。当喷流与环境压力初始平衡时，类邦迪（Bondi）大气将喷流限制为宽抛物线形状（喷流半径R_j∝z^{0.649±0.003}），并产生一系列重联激波；超压喷流则形成锥形，允许下游电流驱动扭结不稳定性发展。基于模拟，推导了主要依赖喷流功率和环境压力的扭结稳定性判据，还使用特殊相对论辐射传输代码计算了多波段发射图：每个重联激波表现为亮节点，类似M87喷流HST-1下游的节点复合体，而具有单个重联激波的喷流在其基部附近形成亮特征，呈现FR I样形态。
英文摘要
Relativistic radio-galaxy jets are conventionally divided into two morphological classes: FR~I and FR~II. Among them, FR~I jets have relatively low radio luminosities and edge-darkened morphologies, indicating they undergo substantial deceleration and disruption on sub-kiloparsec to kiloparsec scales, often developing a turbulent and plume-like morphology. Here, we investigate the evolution of relativistic magnetized jets in stratified ambient media using 2D and 3D relativistic magnetohydrodynamic simulations with several ambient profiles. When the jet and ambient pressures are initially balanced, a Bondi-like atmosphere confines the jet to a broad parabolic shape ($R_j\propto z^{0.649\pm0.003}$) and produces a series of recollimation shocks. Over-pressured jets instead produce a conical shape and allow the development of the current-driven kink instability in the downstream. Based on the simulations, we derive a kink-stability criterion that depends primarily on the jet power and ambient pressure. We also calculate multi-frequency emission maps using a special relativistic radiative transfer code. Each recollimation shock appears as a bright knot, resembling the knot complex downstream of HST-1 of the M87 jet, whereas a jet with a single recollimation shock develops a bright feature close to its base and thus exhibits an FR~I-like morphology.
CommentsAccepted for publication in ApJ
