A Few Tens au Scale Physical and Chemical Structures Around Young Low-Mass Protostars

This book characterizes the kinematic and chemical structures of disk-forming regions around low-mass protostellar sources and their interplay based on Atacama Large Millimeter/submillimeter Array (ALMA) observations. It describes the chemical evolution of molecules formed in an interstellar gas using the ALMA observations of 5 Sun-like protostars at a spatial resolution of a few tens au scale, which unveils the physical mechanism of star and planetary formation.

The book reviews the author’s successful works, focusing on two key findings: (i) A drastic change in the chemical composition of the gas around the centrifugal barrier of the infalling-rotating envelopes, and (ii) the chemical composition in the disk-forming regions, which varies from source to source depending on the chemical characteristics of the parent molecular cloud. These findings are based on the fine characterization of physical structures based on careful kinematic analyses. An additional attraction is theinclusion of the skillful reviews of ALMA observatory and its observation and physical models to describe the observed gas structure.

Introduction.- ALMA Observation.- Model Calculation.- L1527.- IRAS 15398–3359.- IRAS 16293–2422 Source A.- IRAS 16293–2422 Source B.- L483.- Chemical Differentiation.- Physical Diversity.- Conclusion.

Yoko Oya is an Assistant Professor in the Department of Physics at the University of Tokyo. Her work focuses on the physics and chemistry of star and planet formation. She received her bachelor’s, master’s and Ph.D. from the University of Tokyo. She was awarded a Research Fellowship for Young Scientists (DC1) by the Japan Society for the Promotion of Science (JSPS) in 2015, and was supported by JSPS during her doctoral course. In 2018, she won the University of Tokyo President’s award and the School of Science Encouragement Award as an outstanding graduate student.