坠落剖析：原恒星盘吸积流产生的静止及超开普勒螺旋臂
Anatomy of a Fall: Stationary and super-Keplerian spiral arms generated by accretion streamers in protostellar discs
AI总结：
针对晚期下落对原行星盘的物质补充及亚结构影响，本文通过3D光滑粒子流体动力学模拟顺向流-盘相互作用，揭示其激发的螺旋臂具有静止至超开普勒的多模式速度、长寿命等特性，为观测诊断提供依据。
摘要：
晚期向演化原行星盘的下落是物质、角动量补充及盘亚结构的重要来源。本文采用3D光滑粒子流体动力学模拟，对顺向流与盘的相互作用进行建模。初始抛物线流与盘物质相互作用激发盘偏心率，其持续时间可达10^5年量级。研究发现，流在盘中激发的螺旋臂具有多种模式速度，范围从静止到超开普勒；不同模式速度的螺旋臂可同时存在，为观测诊断提供途径。流激发的螺旋臂与大质量外伴星产生的螺旋臂相似，其螺距角朝向扰动源增大；此外，螺旋臂可出现大幅突然的螺距角变化。流激发的螺旋臂寿命长，约为初始流下落时标（~10^4年）的3-4倍；与盘初始相互作用后，盘中持续存在低m方位模式。
英文摘要：
Late-stage infall onto evolved protoplanetary discs is an important source of material and angular momentum replenishment, and disc substructures. In this paper we used 3D smoothed particle hydrodynamics simulations to model streamer-disc interactions for a prograde streamer. The initially parabolic streamer interacts with the disc material to excite disc eccentricity, which can last on the order of $10^5$ years. We found that the spiral arms the streamer excited in the disc can have a variety of pattern speeds, ranging from stationary to super-Keplerian. Spiral arms with various pattern speeds can exist simultaneously, providing a way to diagnose them in observations. Streamer induced spirals appear similar to those generated by a massive outer companion, where the pitch angle of the spiral increases towards the source of the perturbation. Additionally, the spirals arms can show large and sudden pitch angle changes. Streamer induced spirals are long-lived, lasting approximately $3-4\times$ longer than the initial streamer infall timescale ($\sim$$10^4$ years). After the initial interaction with the disc, a long lasting low $m$ azimuthal mode persists in the disc.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
