INVITED TALK Session 3 (Observations Overview)

Role of Centrifugal Barrier in Physics and Chemistry of Disk Formation

Nami Sakai (RIKEN, Saitama, Japan)

Toward a thorough understanding of planet formation in Solar type protostars, one of the most important targets to be explored is 
formation of a Keplerian disk in the early stage of protostellar evolution. Furthermore, the physical process of the disk formation will 
significantly affect an initial chemical composition for a protoplanetary disk. We have explored the kinematic structure of the gas 
associated with the Class 0/I protostar L1527 by using molecular lines of various species. As a result, we have discovered a drastic 
chemical change at the centrifugal barrier probably due to the accretion shock. Such a phenomenon has not been predicted so far in any 
chemical models, and its discovery provides us with a new insight into the physical and chemical processes associated with the disk 
formation. In this talk, I would like to introduce recent progress of disk formation study and its further application to various protostellar 
sources.