Title: Infall and Outflow Activities in Star formation

Speaker: Dr. Gang Wu (Xinjiang Astronomical Observatory, Chinese Academy of Sciences)

Time: 10:00am, May 10, 2024

Location: 5-516, PMO Xianlin Campus

Abstract: The accretion and ejection of material are the two fundamental processes driving star formation. However, neither of these processes is yet well understood, as we still have limited evidence regarding the origin of tracers used to monitor them, as well as our limited knowledge of the accretion/ejection interface and their physical connection. Observing infall is crucial for comprehending the accretion process in star formation. Continuous efforts have been made to improve our capacity for detecting infall motions, aiming to achieve a comprehensive understanding of these motions in star-forming regions across a wider range of evolutionary stages and spatial scales. In this talk, we emphasize our efforts on a promising infall tracer, i.e. ammonia hyperfine intensity anomalies, which could serve as more effective infall tracers for relatively cold gas and large-scale motions. Meanwhile, the launch and collimation mechanisms of jets remain subject to debate and the details of the interactions between jets and outflows are still unclear. One of the main reasons has been the inadequate angular resolution of current facilities needed to zoom into the launching and collimation zone. Therefore, we aim to utilize the so far highest resolution VLBI observations to study these critical aspects in the close vicinity of the protostars.