This book presents observational studies of the earliest stages of high-mass star formation, as revealed by the Atacama Large Millimeter/submillimeter Array (ALMA). The author investigates the birth environments of high-mass stars by identifying and analyzing their immediate progenitorsdense cores embedded in infrared dark clouds. The book highlights ALMAs capability to detect star formation signatures even in regions lacking bright mid-infrared emission, owing to its high resolution and sensitivity. It also presents a statistical study of core properties, suggesting the necessity of core growth and the discovery of core-scale infall motions that point to the role of external accretion. Based on the largest statistical sample to date, this work places observational constraints on theoretical models and offers new insights into the physical conditions that govern high-mass cluster formation.
Introduction.- Star-formation Signatures from Deeply Embedded
Protostars.- Statistical Study of Core Properties in IRDCs.- Global and Local
Infall.- ALMA View of IRDCs: Constraints on Theoretical Models.- Summary and
Future Prospects.
Kaho Morii is a CfA fellow at the Center for Astrophysics | Harvard & Smithsonian, specializing in radio astronomy. Her research focuses on the early stages of high-mass star formation, utilizing radio interferometers, including the fragmentation, gas dynamics, and magnetic fields in high-mass star forming regions. She received her B.S. from Kyushu University in 2020, and her M.S. and Ph.D. from The University of Tokyo in 2022 and 2025, respectively. During her master's course, she was supported by the Forefront Physics and Mathematics Program to Drive Transformation (FoPM), a World-leading Innovative Graduate Study Program (WINGS). In 2022, she received a research fellowship for young scientists from the Japan Society for the Promotion of Science (JSPS), which supported her doctoral research. In 2024, she received the 19th L'Oréal-UNESCO For Women in Science Japan Fellowship Award. In the following year, she was honored with the Research Encouragement Award from The University of Tokyo's School of Science as an outstanding graduate student.
