- Observational Astronomy
- Galaxy Evolution and Observational Cosmology
- Multimessenger Astronomy and Transients

1995 ~ 1996 Postdoctoral Researcher, Johns Hopkins University
1996 ~ 1998 Postdoctoral Researcher, Space Telescope Science Institute
1998 ~ 2001 Postdoctoral Researcher, Lick Observatory/UC Santa Cruz
2001 ~ 2003 Assistant Research Scientist, California Institute of Technology
2003 ~ Current Professor, Seoul National University

2017 Scientist of the Year Award, Journalist Association of Korea
2019 Academic Award of the Year, Korean Astronomical Society
2020 Excellence in Research Award, Seoul National University