在EarliesT阶段的原恒星流出（POETS）。III。跟踪发光YSO附近盘风和喷流的H2O脉泽
Protostellar Outflows at the EarliesT Stages (POETS). III. H2O masers tracing disk-winds and jets near luminous YSOs
摘要：
早期T阶段的原恒星外流（POETS）调查的目标是在统计上显著的发光年轻恒星物体（YSO）样本（36）中以10-100 AU的尺度对盘-外流界面进行成像，目标是外流的分子和电离成分。通过对22 GHz水脉泽的VLBI观测，在毫角秒尺度上研究了外流运动学。我们采用JVLA在6，13，和22 GHz的A-和B-阵列配置，以确定无线电连续辐射的空间结构和光谱指数。在大约一半的目标中，在与YSO的距离<= 1000 au处观测到的水脉泽跟踪这些运动学结构中的一个或两个：1）与脉泽自行（PM）的准直方向成近角的空间细长分布，以及2）跨越YSO位置的线性LSR速度（Vlsr）梯度。运动学结构（1）很容易解释为原恒星喷流，通过与文献中报告的YSO喷流的热（连续谱和线）发射的独立观测进行比较，在一些目标中得到了证实。运动学结构（2）被解释为几乎是从侧面观察到的盘风（DW），这是基于几个证据：首先，它总是垂直于YSO喷流指向;其次，它在方向和极性上与热辐射中的Vlsr梯度一致（当在文献中报道时）在<= 1000~au的尺度上识别YSO盘;第三，描绘Vlsr梯度的脉泽PM暗示了速度为10-20 km/s的气流运动，方向与盘中平面成大角度。在其余的目标中，脉泽PM不是准直的，而是倾向于沿着两个几乎垂直的方向排列，并且可能起源于相对于边缘稍微倾斜（<= 30度）的DW-射流系统。
英文摘要：
The goal of the Protostellar Outflows at the EarliesT Stages (POETS) survey is to image the disk-outflow interface on scales of 10-100 au in a statistically significant sample (36) of luminous young stellar objects (YSO), targeting both the molecular and ionized components of the outflows. The outflow kinematics is studied at milliarcsecond scales through VLBI observations of the 22 GHz water masers. We employed the JVLA at 6, 13, and 22 GHz in the A- and B-Array configurations to determine the spatial structure and the spectral index of the radio continuum emission. In about half of the targets, the water masers observed at separation <= 1000 au from the YSOs trace either or both of these kinematic structures: 1) a spatially elongated distribution oriented at close angle with the direction of collimation of the maser proper motions (PM), and 2) a linear LSR velocity (Vlsr) gradient across the YSO position. The kinematic structure (1) is readily interpreted in terms of a protostellar jet, as confirmed in some targets via the comparison with independent observations of the YSO jets, in thermal (continuum and line) emissions, reported in the literature. The kinematic structure (2) is interpreted in terms of a disk-wind (DW) seen almost edge-on on the basis of several pieces of evidence: first, it is invariably directed perpendicular to the YSO jet; second, it agrees in orientation and polarity with the Vlsr gradient in thermal emissions (when reported in the literature) identifying the YSO disk at scales of <= 1000~au; third, the PMs of the masers delineating the Vlsr gradients hint at flow motions at a speed of 10-20 km/s directed at large angles with the disk midplane. In the remaining targets, the maser PMs are not collimated but rather tend to align along two almost perpendicular directions, and could originate in DW-jet systems slightly inclined (<= 30 deg) with respect to edge-on.
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。
