세종대학교 두드림 비교과통합관리시스템

물리천문학과 콜로퀴움

‧강연 제목 :  Morphology of High Redshift Galaxies in the Horizon Run 5 Simulation and JWST Observation

‧연사 : KIAS 박창범 교수님

‧일시 : 2024년 6월 5일 (수요일) 17:00~18:30

‧진행 방법 : 영실관 601호

‧신청 가능 대상 : 세종대학교 재학생 누구나

‧신청기간 : 6월 4일 ~ 6월 5일

‧강의 초록

We investigate the formation and morphology of galaxies and their morphological evolution using the Horizon Run 5 cosmological simulation. We measure asymmetry and morphology of stellar mass component of the galaxies with stellar mass M> 2×109 M⊙ to classify them into disk, spheroid, and irregular types.
We find that the initial morphology of the galaxies in the cosmic morning is dominantly disk type with the Sersic index < 1.5. The fraction of disk-type galaxies is ~2/3 and that of irregular or spheroid type is ~1/6 each. Irregular or spheroidal morphology is incidental and transient. The fractions are roughly independent of redshift and also of stellar mass up to 1010M⊙. The fraction of spheroidal and irregular types increases for more massive galaxies, but at a fixed mass the fraction of disks monotonically increases. We use the same morphological parameters to classify the high-redshift galaxies in the JWST observations and confirm the dominance of disk galaxies at redshift > 1 at small masses. The morphological distribution of the JWST galaxies shows that disk galaxies account for 60 − 75% at z=0.6-8 and log M∗/M⊙ < 10 . There is a strong stellar mass dependence of galaxy morphology. All these findings are in good quantitative agreement with the prediction of HR5, but in total disagreement with those of Illustris TNG and Eagle simulations.