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Magnetic Fields in Molecular Clouds—Observation and Interpretation
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主讲人: Huabai Li (The Chinese University of Hong Kong)
地点: Remote Talk
时间: Thursday, May 6, 2021
主持 联系人: Ke Wang
主讲人简介: I received the Ph.D. degree in astrophysics from Northwestern University in 2006. Afterwards, I had worked in the Harvard-Smithsonian Center for Astrophysics and Max Planck Institute for Astronomy. In Aug. 2013, I started the current position in the Department of Physics, The Chinese University of Hong Kong. My research group study how magnetic fields and turbulence regulate star formation; wee use various novel methods in observations, numerical simulations and instrumentation.

The  Zeeman effect and dust grain alignment are two major methods for  probing magnetic fields (B-fields) in molecular clouds, largely  motivated by the study of star formation, as the B-field may regulate  gravitational contraction and channel turbulence velocity. I will review  our observations of B-fields over the past decade, along with our  interpretation. Galactic B-fields anchor molecular clouds down to cloud  cores with scales around 0.1 pc and densities of 104–5 H2/cc.  Within the cores, turbulence can be slightly super-Alfvénic, while the  bulk volumes of parental clouds are sub-Alfvénic. The consequences of  these largely ordered cloud B-fields on fragmentation and star formation  are observed. The above paradigm is very different from the generally  accepted theory during the first decade of the century, when cloud  turbulence was assumed to be highly super-Alfvénic. Thus, turbulence  anisotropy and turbulence-induced ambipolar diffusion are also  revisited.

Speaker: Huabai Li (The Chinese University of Hong Kong)

Place:Remote Talk

   https://zoom.com.cn/j/6223937478?pwd=QU9Pdm12ZHhGUHVKbFhaUWtsUDVMdz09

   Meeting ID: 622 393 7478

   Passcode: 2BYguM

Host:Ke Wang
Time: Thursday, May 6, 2021(4:00PM- 5:00PM)
Biography:
I received the Ph.D. degree in astrophysics from Northwestern University in 2006. Afterwards, I had worked in the Harvard-Smithsonian Center for Astrophysics and Max Planck Institute for Astronomy. In Aug. 2013, I started the current position in the Department of Physics, The Chinese University of Hong Kong. My research group study how magnetic fields and turbulence regulate star formation; wee use various novel methods in observations, numerical simulations and instrumentation.