Colloquium on Jul. 1, 2021

The Scale-dependent Importance of Magnetic Field, Turbulence, and Self-gravity in Star Formation

Speaker: Yue Hu (University of Wisconsin-Madison)

Venue: Video Conference

Time: 16:00 PM, Thursday, Jul. 1, 2021

Abstract:

Understanding how star formation is regulated requires studying the energy balance between turbulence, magnetic fields, stellar feedback, and gravity within molecular clouds. Motivated by the recently-advanced polarimetric capabilities and the velocity gradient technique, our recent theoretical efforts utilizing 3D MHD simulations have provided new ways to characterize the 3D magnetic field structure and the relative importance of the turbulence, magnetic fields, and self-gravity in star-forming clouds. We present IRAM 30 m telescope observations of the 13CO (1-0) emission in the Serpens G3-CG6 molecular cloud and apply to the data a set of statistical methods. These include the probability density functions of column density and the velocity gradients technique. We combine our data with the Planck 353 GHz polarized dust emission observations and Herschel H2 column density. We suggest that the Serpens G3-G6 south clump is undergoing a gravitational collapse. We find that the Serpens G3-G6 south clump’s total magnetic field energy significantly surpasses kinetic energy and gravitational energy. We conclude that the gravitational collapse could be successfully triggered in a supersonic and sub-Alfvenic cloud.

Report PPT:  SWIFAR_Yu Hu.pdf