Analytical Stellar Mass Estimation for eDisk

ABSTRACT :
The ALMA large program eDisk has published a series of first-look papers focusing on each target and is moving to the next phase where we investigate various scientific topics, such as stellar mass, substructures, and chemistry, over the targets. In this phase, I am attempting four analytical methods for estimating stellar mass, without radiative transfer. The first method fits the double power-law function to the edge and ridge points of a position-velocity (PV) diagram along the disk major axis. The second method fits the outer contour of PV diagrams along the disk major and minor axes with a disk+envelope velocity field. The third method finds channels showing a velocity-gradient direction close to the disk major axis. The fourth method fits channel maps with a four-layer disk model. In this workshop, I present a test of these methods using synthetic observations of models on the parameter grid of (stellar mass, disk radius, inclination angle) = (0.25, 0.5, 0.75 Msun) x (50, 100, 250 au) x (10, 45, 80 deg).