□ 연구개요 The final goal of this project is to clarify the impact of protostars on the formation and desorption of water and COMs in the surrounding environment. Toward this goal, we have achieved four objectives: (1) quantified the effects of suprathermal rotation induced by strong radiation from protostars on formation and desorption of ice and COMs, (2) investigated the effect of suprathermal rotation induced by energetic outflows from protostars on formation and desorption of COMs, (3) constrained dust grain sizes in star-forming regions by comparing synthetic modeling of dust emission and polarization with observational data, and (4) investigated the effect of outbursting protostars on water ice, COMs and dust □ 연구 목표대비 연구결과 ● Our results far exceeded the goal, as demonstrated by 30 SCI papers with major contribution published in the top-tier journals of astronomy and astrophysics (ApJ, AJ, A&A, MNRAS). ● For objective (1), we discovered two new physical effects induced by radiative torques (RATs) in the intense radiation of protostars on desorption of COMs from icy grain surfaces, which were termed rotational desorption and ro-thermal desorption. We successfully tested these new mechanisms with observational data from SOFIA and found convincing evidence of rotational desorption in several star-forming regions (SFRs). ● For objective (2), by studying the effect of protostellar outflows on surrounding dust, we found that shocks induced by outflows can spinup nanoparticles to suprathermal rotation and disrupt them into molecules and can also increase anomalous microwave emission from spinning nanoparticles due to grain spinup by mechanical torques (see RP2). We also studied the interaction of protostellar jets on dust grains. We found that it is efficient in destroying nanoparticles in Hoang & Lee (2020). ● For objective (3), we performed synthetic modeling of dust polarization caused by grain alignment and constrained the grain sizes in SFRs by comparing our numerical model of dust polarization with observational data from SOFIA/HAWC+. We found that grains in SFRs are smaller than in the diffuse ISM due to rotational disruption by RATs. ● For objective (4), we investigated the effect of episodic accretion to protostars on grain alignment and disruption by varying the protostar luminosity. We found that the increased luminosity extends the region of aligned grains. We extended our study for the case of massive protostars and found that icy grains in these intense sources are efficiently disrupted and the disruption zone is much broader than the case of low-mass protostars. □ 연구개발성과의 활용 계획 및 기대효과(연구개발결과의 중요성) ● Our results were highlighted by 2020 American Astronomical Society and reported by major international news such as New York Times, American Scientists, Forbes, etc ● Awarded the Excellent Research Performance by the Chairman of National Research Council of Science and Technology (NST) in 2021. ● Awarded the Distinguished Academic Award from Korea Astronomical Society (2022). Four Grand Prizes from KASI (2019-2022) ● Gave ~ 10 invited talks at the major international conferences, invited colloquia, and invited lectures for international students/postdocs at various schools (source : 연구결과 요약문 2p)
- 연구책임자 : Thiem Hoang
- 주관연구기관 : 한국천문연구원
- 발행년도 : 20230300
- Keyword : 1. 원시성;별탄생 영역;얼음;복합 유기 분자;먼지 티끌; 2. protostars;star forming regions;ice;complex organic molecules;dust;