Rotating outflows from protostellar disks might trace extended magnetohydrodynamic (MHD) disk winds (DWs), providing a solution to the angular momentum problem in disk accretion for star formation. In the jet system HH 212, a rotating outflow was detected in SO around an episodic jet detected in SiO. Here we spatially resolve this SO outflow into three components: a collimated jet aligned with the SiO jet, the wide-angle disk outflow, and an evacuated cavity in between created by a large jet-driven bow shock. Although it was theoretically predicted, this is the first time that such a jet–DW interaction has been directly observed and resolved, and it is crucial for the proper interpretation and modeling of non-resolved DW candidates. The resolved kinematics and brightness distribution both support the wide-angle outflow to be an extended MHD DW dominating the local angular momentum extraction out to 40 au, but with an inner launching radius truncated to ≳4 au. Inside 4 au, where the DW may not exist, the magnetorotational instability might be transporting angular momentum outward. The jet–DW interaction in HH 212, potentially present in other similar systems, opens an entirely new avenue to probe the large-scale magnetic field in protostellar disks.

原恒星盘的旋转流出物可能会追踪扩展的磁流体动力学 (MHD) 盘风 (DW)，从而为恒星形成的盘吸积中的角动量问题提供解决方案。在射流系统 HH 212 中，在 SO 中检测到旋转流出，围绕在 SiO 中检测到的偶发射流。在这里，我们在空间上将这种 SO 流出分解为三个部分：与 SiO 射流对齐的准直射流、广角圆盘流出以及由大型射流驱动的弓形激波在两者之间形成的真空腔。尽管这是理论上的预测，但这是第一次直接观察和解析这种喷射-DW 相互作用，这对于正确解释和模拟未解析的 DW 候选者至关重要。解析的运动学和亮度分布都支持广角流出是一个扩展的 MHD DW，主导局部角动量提取到 40 au，但内部发射半径被截断为 ≳4 au。在 4 au 内，可能不存在 DW，磁旋转不稳定性可能正在向外传输角动量。HH 212 中的喷流-DW 相互作用可能存在于其他类似的系统中，为探测原恒星盘中的大规模磁场开辟了一条全新的途径。