HURACAN：L1688内部恒星与星际自行的比较
HURACAN: A comparison of stellar and interstellar proper motions inside L1688
浏览论文内容
中文总结 AI 辅助
本研究首次直接测量蛇夫座L1688分子云内星际介质的横向运动，发现其与年轻恒星运动存在偏差，证实恒星反馈对星际介质运动的塑造作用，并指出近红外观测为星际介质动力学研究提供新途径。
中文摘要 AI 辅助
分子云与其内部形成的年轻恒星族群在运动学上耦合的假设，在观测上仍缺乏充分约束。由于星际介质（ISM）运动的横向分量$v_{\textrm{t}}$在很大程度上未知，即便距离最近的分子云，其三维运动学状态仍不完整。我们首次直接测量了蛇夫座分子云L1688内部星际介质的横向运动，并将其与周围年轻恒星族群的运动学特征进行比较。该测量通过对存档数据应用基于强度的图像配准获得，使我们能够生成研究区域的自行场，并确定分子云的整体运动为$(μ_{α^*},μ_δ)^{\mathrm{ISM}}_{\mathrm{median}}=(-3.0, -24.1)$ mas yr$^{-1}$。这一运动与上天蝎座最年轻恒星族群的运动学特征相差$3\pm1$ km s$^{-1}$，凸显了在恒星形成区附近用恒星作为星际介质运动代理时可能存在偏差。通过将分子云运动与该区域最年轻恒星族群以及位于云内的B型星Oph S1的运动进行比较，我们发现恒星反馈必然在过去数百万年间动态塑造了星际介质的运动。此外，通过研究L1688中出现的一个壳状星际介质结构，我们发现证据表明该天体既不太可能是典型的Herbig-Haro天体，也不是超新星遗迹，其起源仍是个谜。我们的结果表明，存档及未来的高分辨率近红外观测能够且将继续实现对近邻分子云星际介质横向运动的测量，为研究星际介质动力学打开了一扇仅靠径向速度无法企及的新窗口。
英文摘要
The assumption that molecular clouds are kinematically coupled to the young stellar populations forming within them is observationally still poorly constrained. With the transverse component $v_{\textrm{t}}$ of the interstellar medium (ISM) motion being largely unknown, the three-dimensional kinematic state of even the closest clouds remains incomplete. We provide the first direct measurement of the transverse motion of the ISM inside the Ophiuchus cloud L1688 and compare it with the kinematics of the surrounding young stellar populations. The measurement was obtained using intensity-based image registration applied to archival data, allowing us to generate a proper motion field of the studied regions and determine the cloud's bulk motion, $(μ_{α^*},μ_δ)^{\mathrm{ISM}}_{\mathrm{median}}=(-3.0, -24.1)$ mas yr$^{-1}$. This motion differs from the kinematics of the youngest population in Upper Scorpius by $3\pm1$ km s$^{-1}$, highlighting the possibility of a bias when using stars as a proxy for the ISM motion near star-forming regions. By comparing the cloud's motion with that of the youngest stellar population in the region and the B-star Oph S1 located within the cloud, we find that stellar feedback must have dynamically shaped the motion of the ISM over the last few million years. Furthermore, by studying a shell-like ISM structure appearing in L1688, we find evidence suggesting that this object is likely neither a typical Herbig-Haro object nor a supernova remnant, with its origin remaining a mystery. Our results demonstrate that archival and future high-resolution near-infrared observations can and will continue to enable measurements of ISM transverse motions in nearby clouds, opening a new window for studying ISM dynamics that is not accessible when using radial velocities alone.
