Oral Presentation

First-look results of Early Planet Formation in Embedded Disks (eDisk): Revealing kinematic substructures in the Class 0 protostellar object CB 68

Author(s): Miyu Kido, Shigehisa Takakuwa, Kazuya Saigo (Kagoshima university), and the eDisk Collaboration

Presenter: Miyu Kido (Kagoshima university)

We will present first-look results of the Class 0 protostar CB 68 obtained from our ALMA Large Program eDisk. Class 0 protostar CB 68 is formed in an isolated Bok globule and one of the youngest sources in the eDisk samples. Thus, it is a good target to understand very early stage of low-mass star formation. We spatially resolved the dusty disk of CB 68 in the 1.3-mm dust-continuum emission at a spatial resolution of 6 au and revealed an edge-on disk (i ~ 73deg) with a radius of ~ 20 au. The intensity profiles of the dust emission both along the minor and major axes exhibit various asymmetric features. The asymmetry along the minor axis reflects the disk flaring traced by the optically-thick 1.3-mm dust-continuum emission. It is an apparent feature, suggesting that dust grains in the disk are yet to settle onto the mid-plane. In contrast, asymmetries along the major axis are originated from real non-axisymmetric structures. The C18O (J=2-1) emission shows a clear Keplerian rotation signature in the disk, and the mass of the central protostar is derived to be ~ 0.13 solar mass. Furthermore, we found three elongated structures with a thousand au connected to the protostellar disk in the infalling envelope on the northern side. We discuss the origin of these three elongated structures by comparing simple models and spatial/velocity structures seen in our observations.