​Abstract of the Program

Our ALMA Large Program "Early Planet Formation in Embedded Disks (eDisk)" is to investigate substructures and physical properties of the embedded disks around 8 Class 0 and 11 Class I protostars, including two sources from the ALMA Science Archive, at a high spatial resolution of ~5 au (0.04 arcsec) in the 1.3-mm continuum emission and CO (2-1) isotopologue lines. The latest ALMA studies, such as DSHARP, have shown that substructures (rings/gaps, or spirals) are ubiquitous in protoplanetary disks around Class II sources. Such substructures may be a consequence of planet formation in the disks. It is therefore very important to see when substructures start to develop in disks. Because only a few embedded disks around protostars have been observed at a high angular resolution, our large protostellar sample allows us to explore for the first time how ubiquitous such substructures are in embedded disks. Observations in CO isotopologue lines help us to reveal the presence of Keplerian disks, providing us with crucial physical parameters, in particular, the dynamical mass of the protostars. Along with the Class II disk data, these new, homogeneous protostellar data will provide us a unique opportunity to study disk evolution and planet formation at the earliest stages.