Bon-Chul Koo carries out a multi-wavelength study of supernova remnants, star-forming regions, and the diffuse interstellar medium in order to understand the formation, evolution, and death of massive stars as well as their role in the Galaxy.

From spectroscopic observations of this relic material of a star exploded 330 years ago, we can learn the final evolution and explosion of massive stars. [Red = Near-infrared Fe+(1.64 micron) image obtained by the 5-m Palomar Hale telescope: Green = X-ray continuum (4.2-6.5 keV) image from Chandra: Blue = X-ray Fe K (6.52-6.94 keV)]