演講資訊

摘要：

Although gravitational collapse of molecular gas has been widely accepted from the theoretical viewpoints of star formation, acquiring direct observational evidence of gas infall motions poses a challenge. With high sensitivity and angular resolution, ALMA provides an invaluable opportunity for probing inward motion of molecular gas toward young stellar objects. In this talk, I will update recent progress for measuring infall motion in low-mass protostars with ALMA observations. In particular, I will focus on the case of NGC 1333 IRAS 4A, a young low-mass protostellar binary, whose components are referred to as 4A1 and 4A2. Based on radiative transfer modeling exercises, we find that the physical parameters inferred from earlier low-resolution observations cannot be directly extrapolated down to the inner region of 4A1. Possible reasons for the discrepancies between the observed and modeled profiles will be discussed.