Gas Infall and Core Growth in High-mass Star Formation
Speaker: Kaho Morii (D3, The University of Tokyo)
Abstract:
Understanding gas dynamics is a key to understanding star formation. Recent observations of infrared dark clouds (IRDCs), the birthplace of high-mass stars, imply the necessity of core growth by feeding gas from the surroundings. To explore this, we conducted ALMA observations of a 70 μm dark region within a massive, dense IRDC (~1180 Msun, 12 K). Our analysis of 19 cores, including two intermediate-mass cores (10 and 4 Msun), shows signs of gas infall, with velocities between 0.3-1.4 km/s and infall rates of 10^-4 to 10^-3 Msun/yr. These are higher than in low-mass regions and can be considered a strong indication of core growth, enabling the formation of high-mass stars from intermediate-mass cores that would not originally be able to form high-mass stars at their current mass.