Host: Fabo Feng
Join Tencent Meeting：https://meeting.tencent.com/dm/vNOGMT9fH8Kl
Meeting ID: 322889325 (no password）
Abstract:
The process of star formation represents one of the most enduring enigmas in the field of astronomy. At the onset of the current century, the prevailing belief among astronomers was that solely super-Alfvénic turbulence could rival gravity in the process of star formation. This perspective gradually evolved during the second decade, as polarized thermal dust emission implied a significant level of organization in magnetic fields (B-fields), signifying dynamically strong B-fields and thus anisotropy in both turbulence and gravitational collapse. On the other hand, the relation between the magnetic field (B) and density (n) deduced from Zeeman measurements, expressed as B~n^2/3 , has been interpreted as isotropic gravitational collapse — a consequence of dynamically weak B-fields. The contradiction between the two B-field tracers remains a major mystery (see, e.g., the latest PPVII review chapter). The logic and data behind the above statement will be discussed, followed by my proposed solution to the mystery and its implications for star formation.
Biography:
Hua-bai Li is a Professor of Physics at The Chinese University of Hong Kong (CUHK) since 2013. After earning his PhD from Northwestern University (2006), he conducted research at the Harvard-Smithsonian Center for Astrophysics and the Max Planck Institute for Astronomy before joining CUHK. His group investigates star formation, employing novel observational techniques, numerical simulations, and custom instrumentation such as SHARP (on CSO), APol (on ASTE), and ROGer (to be installed on GLT). His research, recognized for resolving long-standing debates
in interstellar medium dynamics, has been published in leading journals including Nature and Nature Astronomy. Prof. Li’s work bridges theoretical predictions with observational breakthroughs, particularly in linking magnetic fields and turbulence to cloud structure and star formation.
