천문우주과학과

일시:  2021년 3월 18일 목요일 오후 4시
       (ZOOM 회의 ID:932 6693 1767, PW:612443)

연사:  오슬희 박사님(ANU)

제목: Kinematics of galaxy bulges, disks, and gases

 초록:  

It will be introduced how to extract the rotation velocity and velocity dispersion of galaxies from 3D spectroscopy data cubes. The current stage of spectroscopic bulge-disk decomposition will also be reviewed. We investigate the stellar kinematics of the bulge and disk components using SAMI 3D spectroscopy data. The spatially resolved rotation velocity (V) and velocity dispersion (σ) of bulge and disk components have been simultaneously estimated using the penalised pixel fitting (PPXF) method with photometrically defined weights for the two components. The spin parameter λR indicates bulges are pressure-dominated systems, and disks are supported by rotation. The two components show Tully-Fisher and Faber-Jackson relations with similar slopes but different intercepts suggesting that the galaxy stellar mass scales with both V and σ for both bulge and disk components of all galaxy types. Our findings suggest that the relative contributions of the two components explain, at least to first order, the complex kinematic behaviour of galaxies. Looking further ahead, we compare gas and stellar kinematics in various galaxy types (e.g. star-forming galaxies, AGNs), and discuss gas and stellar kinematics as proxies for the dynamical masses.