Ohashi's Research Group
Research Field
Nagayoshi Ohashi is a Research Fellow at the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) and an observational astronomer specializing in star and planet formation. His research focuses on protostellar disks and molecular cloud dynamics, using leading facilities such as ALMA, SMA, and the Nobeyama Millimeter Array. He has made several pioneering contributions to the field, including the first direct imaging of infalling gas motions in a protostellar envelope and the first kinematic identification of Keplerian disks around protostars—methods that are now widely used to study early stellar evolution.
He currently serves as the Principal Investigator of the ALMA Large Program Early Planet Formation in Embedded Disks (eDisk), which has produced more than 20 refereed papers since 2023 and has had a substantial international impact. His leadership has been recognized through the Academia Sinica Investigator Project Grant, as well as frequent invitations to speak at major international conferences. In addition to his scientific work, he has played key technical and leadership roles in the development of SMA and ALMA, significantly contributing to Taiwan’s presence in global astronomy.
Through his research, international collaborations, and mentoring of students and postdoctoral researchers, Ohashi provides an excellent training environment for interns interested in frontier research on star and planet formation.
Ohashi’s research group conducts observational and theoretical studies of star and planet formation. The group currently consists of four members, including Ohashi, one research assistant, one postdoctoral fellow, and one project researcher.
Ohashi holds a weekly group meeting, jointly organized with other research groups working on star and planet formation, to encourage broader scientific discussion and collaboration. In addition, he meets individually with each group member on a weekly basis to provide detailed guidance on their ongoing research projects.
Because many of the group’s research projects are carried out in close collaboration with international researchers, Ohashi and group members regularly participate in video conferences with collaborators based overseas. All scientific discussions within the group are conducted in English, providing a fully international research environment and strong training opportunities for students and interns.
- star and planet formation
- formation and evolution of circumstellar disks
- mass infall and outflow during star formation
- radio and NIR observations
- high resolution imaging using radio interferometers
- Academia Sinica Investigator Award (2024)
- Visiting Associate Professor, University of Bordeaux (2009)
- NSC (Taiwan) Research Award (1999, 2000)
- The Astronomical Society of Japan (ASJ) Young Astronomer Award (1999)
- Ph.D., Physics, Nagoya University (1992)
- M.S., Physics, Nagoya University (1989)
Job Description
The detailed job descriptions are as follows;
- The data we will use is dust continuum data at 1.3 mm wavelength obtained with the Atacama Millimeter and submillimeter Array (ALMA).
- The target sources are protostars located in the Ophiuchus Star-Forming Regions. As needed, we will also use the data obtained in the ALMA large project “Early Planet Formation in Embedded Disks (eDisk).
- We use the PRIISM technique to achieve a higher angular resolution.
- The images will be conducted using Python scripts. In addition, obtained images will be visualized in color and contours with python scripts as well.
- As needed papers related to the targets we will work in this projects will be also investigated to obtain additional information on the targets.
Preferred Intern Educational Level
interns with Bachelor of Science
Skill sets or Qualities
Candidates should have a basic knowledge of star and planet formation and also circumstellar disks around young stellar objects. It would be better for candidates to have previous experiences to reduce radio emission data particularly data obtained using radio interferometer. Basic skills to use a linux computer and python scripts are also required.