제목 : Mid-infrared excess emission of galaxies and implications for the star formation history
연사 : 고종완 박사님 (한국천문연구원)
언어 : 한국어
The mid-infrared (IR) data for nearby galaxies become increasingly important because many observations of nearby galaxies show a clear excess over stellar photospheric emission at 8–24 μm. In old stellar systems (i.e., early-type galaxies), the most likely origin of such mid-IR excess is circumstellar dust around asymptotic giant branch (AGB) stars. I will provide detailed introduction to mid-IR excess emission of galaxies (mainly early-type galaxies) and its applications to trace star formation activities. Finally, I will present the most recent work where we show that old stellar systems with mid-IR excess emission have experienced star formation within the last 1–5 Gyr and that the mid-IR emission is a useful diagnostic tool for probing recent star formation activity in quiescent (i.e., without current star formation) galaxies.