詹姆斯·韦布空间望远镜/中红外仪器对边缘取向的II类源HV Tau C分子氢风的探测
JWST/MIRI Detection of Molecular H$_2$ Winds from an Edge-on Class II Source HV Tau C
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中文总结 AI 辅助
研究利用JWST/MIRI-MRS数据分析近边缘取向的II类盘HV Tau C分子氢发射特性，探测到广角双锥分子风，估计其质量损失率等，发现分子H₂风对盘演化等仍重要，吸积率或因边缘取向被低估。
中文摘要 AI 辅助
原行星盘的演化受中央恒星吸积和通过喷流与风的质量损失调节。虽然原子和电离外流常见，但演化的II类盘中分子风很少被探测到。我们描述了近边缘取向的II类盘HV Tau C分子氢（H₂）发射的空间、热、运动学和动力学特性，并评估其分子风的影响。利用来自MINDS第1周期GTO计划的JWST/MIRI-MRS数据，分析空间分辨的纯转动H₂发射。转动和位置-速度图限制激发和运动学，由此估计风的特性。我们探测到延伸的H₂发射，追踪到一个广角双锥分子风，延伸到近红外散射光盘、ALMA 887μm尘埃连续体和致密¹²CO（J = 3 - 2）气体盘之外。H₂转动图需要温暖（约600K）和高温（约2000K）成分，类似于年轻原恒星中的情况。气体显示出几十km s⁻¹的向外运动和几十到几百年的动力学时间尺度。推断的质量损失率约为10⁻⁸ M☉ yr⁻¹，而从H I线得出的吸积率为10⁻¹⁰ - 10⁻⁸ M☉ yr⁻¹。由于边缘取向的几何形状，吸积率可能被低估。我们的结果表明，广角分子H₂风可以持续到II类阶段，流出率与一些原恒星系统相当，这表明这种风可能对角动量去除、盘演化和消散仍然很重要。
英文摘要
The evolution of protoplanetary disks is regulated by accretion onto the central star and mass loss through jets and winds. While atomic and ionized outflows are commonly observed, molecular winds in evolved Class II disks remain rarely detected. We characterize the spatial, thermal, kinematic, and dynamical properties of molecular hydrogen (H$_2$) emission from the nearly edge-on Class II disk HV Tau C and assess the impact of its molecular wind. We also constrain accretion using H I recombination lines detected in the same mid-infrared spectrum. Using JWST/MIRI-MRS data from the MINDS Cycle 1 GTO program, we analyze spatially resolved pure-rotational H$_2$ emission. Rotational and position-velocity diagrams constrain excitation and kinematics, from which we estimate wind properties. We detect extended H$_2$ emission tracing a wide-angled, biconical molecular wind extending beyond the near-infrared scattered-light disk, ALMA 887 $μ$m dust continuum, and compact $^{12}$CO ($J=3$-$2$) gas disk. The H$_2$ rotational diagram requires warm ($\sim$600K) and hot ($\sim$2000K) components, similar to those in younger protostars. The gas shows outward motions of a few tens of km s$^{-1}$ and dynamical timescales of tens to hundreds of years. The inferred mass-loss rate is $\sim10^{-8}$ M$_\odot$ yr$^{-1}$, while accretion rates derived from H I lines are $10^{-10}$-$10^{-8}$ M$_\odot$ yr$^{-1}$. The accretion rate may be underestimated because of the edge-on geometry. Our results show that wide-angled molecular H$_2$ winds can persist into the Class II phase, with outflow rates comparable to some protostellar systems, suggesting that such winds may remain important for angular momentum removal, disk evolution, and dispersal. (Abstract modified; see the paper for the full version.)
