We present a spatio-kinematical analysis of the CO (J = 2 → 1) line emission, observed with the Atacama Large Millimeter/submillimeter Array (ALMA), of the outflow associated with the most massive core, ALMA1, in the 70 μm dark clump G010.991–00.082. The position–velocity (PV) diagram of the molecular outflow exhibits a peculiar S-shaped morphology that has not been seen in any other star-forming region. We propose a spatio-kinematical model for the bipolar molecular outflow that consists of a decelerating high-velocity component surrounded by a slower component whose velocity increases with distance from the central source. The physical interpretation of the model is in terms of a jet that decelerates as it entrains material from the ambient medium, which has been predicted by calculations and numerical simulations of molecular outflows in the past. One side of the outflow is shorter and shows a stronger deceleration, suggesting that the medium through which the jet moves is significantly inhomogeneous. The age of the outflow is estimated to be τ ≈ 1300 yr, after correction for a mean inclination of the system of ≈57.

我们提出了对 CO ( J = 2 → 1) 线发射的空间运动学分析，通过阿塔卡马大型毫米/亚毫米阵列 (ALMA) 观察到与最大质量的核心 ALMA1 相关的外流，在 70 μm 暗团块 G010.991–00.082。分子流出的位置-速度（PV）图表现出一种特殊的 S 形形态，这在任何其他恒星形成区域都没有见过。我们提出了双极分子流出的空间运动学模型，该模型由减速的高速分量和较慢的分量包围，其速度随着距中心源的距离而增加。该模型的物理解释是当射流从周围介质中夹带物质时减速，这在过去已经通过分子流出的计算和数值模拟进行了预测。流出的一侧较短并显示出更强的减速，表明射流移动的介质明显不均匀。流出年龄估计为τ ≈ 1300 yr，校正系统的平均倾角 ≈57。