천문우주과학과

일시 : 2023년 10월 11일 수요일 오후 4시 자4514호(세미나실)

연사 : 임기정 박사님 (자연과학연구소)

제목 : The Volumetric Star Formation Law in Nearby Edge-on Galaxies

초록 : We present a study of the volumetric star formation law (SFL) in a sample of edge-on galaxies (NGC 891, 4013, 4157, 4302, 4565, and 5907) using BIMA/CARMA/ALMA CO, VLA HI, KPNO H-alpha, and Spitzer 24 micron data. We measure the scale heights of CO, HI, and the star formation rate (SFR), which increase significantly as a function of radius. Using the measured scale heights along with the vertically integrated surface densities, we infer the midplane volume densities to investigate the relationship between the SFR and the gas (HI, H2, and the total gas). Additionally, we compare the volumetric SFL with the vertically integrated SFL (Kennicutt–Schmidt law) and find strong power-law correlations between the SFR and the gas (H2 and HI+H2) in both volume and surface densities. The power-law slopes for both SFLs in terms of the molecular gas are similar to each other. However, the slope for the total gas in the volumetric SFL is noticeably smaller than the slope in the vertically integrated SFL. The volumetric star formation efficiencies (SFEs) for the molecular and total gas are fairly constant, while the SFE for the atomic gas decreases as a function of radius.