Star Formation and Evolution
The Star Formation and Evolution research group has focused on observational studies at millimeter and submillimeter wavelengths using domestic facilities, such as TRAO and the KVN at KASI and the combined VLBI network at KVN + VERA (KaVA), and foreign facilities such as ALMA and the James Clerk Maxwell Telescope (JCMT), in which KASI participates as a member of the East Asian Consortium. The Star Formation and Evolution research group also leads the KVN Key Science Program (KSP) and KaVA Large Program in the fields of star formation and evolved stars.
The research topics are as follows.
The research topics are as follows.
Star Formation
NGC 1333 IRAS 4A: SiO Outflow
- Kinematical and chemical studies of the formation of dense cores and filamentary clouds
- Studies of magnetic fields in dense cores and filaments
- Studies of outflows and inward motions in very low luminosity objects
- Studies of the origin of proto-brown dwarfs and their disk formation
- Study of the structure, physics, and evolution of protostars using radio interferometric imaging
- Study of the physics and chemistry of infrared dark clouds and massive star-forming regions using radio and infrared observations
- Study of protostellar collapse and young cluster formation using radio spectroscopy and infrared photometry
- Statistical study of water and methanol masers in star-forming regions
- VLBI measurements of the three-dimensional velocity fields of water and methanol masers around high-mass young stellar objects
- Study of the physical and chemical properties and magnetic field characteristics of high-mass star-forming regions
- Unraveling the physical and chemical properties of Planck cold clumps
Evolved Stars
VX Sgr : H2O and SiO masers
- Investigating spatial structures and dynamical effects from 43/86/129 GHz SiO masers to 22 GHz H2O maser regions (i.e., from the atmosphere to the circumstellar envelope) according to stellar pulsation through simultaneous time monitoring observations with the KVN single dish and KVN and KaVA VLBI network
- Studies on correlations and differences among maser properties (e.g., spatio-kinematic properties) among SiO J=1-0, J=2-1, J=3-2 masers to constrain SiO maser excitation and pumping models
- Studies of dynamical evolution from asymptotic giant branch (AGB) to post-AGB stars: Morphology and mechanism, characteristics of SiO and H2O maser properties
- For the above studies, the evolved star team has conducted the KVN Key Science Program “Simultaneous Monitoring of KVN 4 Bands toward Evolved Stars” and the KaVA Large Program “ESTEMA (Expanded Study on Stellar Masers)” regularly since 2015.