Kuo, I-Hsuan (ASIAA/NTU); Yen, Hsi-Wei (ASIAA); Gu, Pin-Gao (ASIAA)
ALMA observations revealed an eccentric dust cavity with e~0.1 in the transitional disk MWC758. To investigate the origins of the eccentricity of the dust cavity, we analyzed the gas kinematics in the MWC758 disk using ALMA archival data of the 13CO and C18O 3-2 line emission and performed fitting with Keplerian disk models using the radiative transfer code DiskFit. We found significant velocity deviations from the best-fit Keplerian rotation at the radius of the dust cavity. We examined several possibilities that may cause the velocity deviations, such as pressure gradient, height of the emitting layer, infall motion, inner warp, and vortices. We found that an eccentric orbital motion in the disk best explains our results, and the eccentricity of the gas motion was estimated to be 0.1+/0.03 at the radius of the dust cavity. In this presentation, I will introduce our result and discuss its implications on dust-gas coupling and planet-disk interaction in the MWC758 disk.