演講資訊

摘要：

Magnetic fields are a key component in star formation theories. Nevertheless, their exact role in the formation of stars is still a topic of debate due to the difficulty in measuring magnetic fields. Over the past decades, observers established a standard paradigm to evaluate the role of magnetic fields in star-forming clouds with the physical parameters, such as mass-to-magnetic-flux ratio and Alfven Mach number. However, these methods are designed for the data with insufficient resolution, and thus only describe the global properties over an entire molecular cloud. While the new generation instruments have the capability to resolve magnetic fields in molecular clouds in detail, a new paradigm is needed to reveal the role of magnetic fields locally within a molecular cloud. In this talk, I will present our studies on the interplay between local magnetic fields, gravity, and turbulence within two molecular clouds IC5146 and G33.92+0.41. Our analysis reveals that the two clouds are likely formed in two different extreme condition: strong magnetic field and negligible magnetic field. This suggests that the role of magnetic fields is environment-dependent, and star formation could occur in a variety of environments.