천문우주과학과

일시:  2019년 5월 16일 목요일 천문우주과학과 세미나실 (기2514호)

연사:  강지현 박사님 (한국천문연구원)

제목:  “Missing” Supernova Remnants and the Magnetic Fields in Massive Star Forming Regions.

초록:  In this talk, I would like to talk about two topics, supernova remnants and star forming regions, which I studied in the Arecibo observatory and in the KASI, respectively. 

 One of the unsolved issues regarding supernova remnants (SNRs) in the Milky Way is that the number of the known SNRs (274; Green 2009) is much less than that of the expected (~20,000). Based on the idea that the old SNRs are faint in the radio continuum and X-rays, yet the shocked HI gas of the remnants could move rapidly (~ 100 km/s), we searched the faint, fast moving HI gases in the HI survey data. The high angular resolution follow-up observations using the Arecibo 305-m and the Green Bank 100-m telescopes revealed that they are indeed expanding shells and good candidates of “missing” supernova remnants.

 The role of magnetic field over turbulence in dense star forming regions is under debate, especially in massive cores. We statistically investigated polarization properties of the methanol maser transition lines towards the massive star forming regions using the KVN telescope. With the follow-up observations of two massive star forming regions, G10.34 and G10.32, using the KVN VLBI and the ALMA telescopes, we found that they are the sites of multiple outflows and young stellar objects. We also found that the magnetic field environments in the masing regions are stable and consistent over a few AU to a few hundreds AU scales.