Early Planet Formation in Embedded Disks (eDisk): A first look at the Class 0 prostostar GSS30 IRS3

Protoplanetary disks are the places where planets are formed during the star formation process. In recent years, the focus of research efforts to better understand planet formation has been on Class II sources, identifying substructures in approximately one hundred of them. The origins of these substructures, however, remain a topic of debate. Planet formation is the leading theory among the different mechanisms proposed to explain the formation of these substructures. To investigate whether these substructures are the result of planet formation, it is necessary to study the earlier evolutionary stages of protoplanetary disks, specifically Class 0/I disks, which have not been studied in detail. The ALMA Large Program "Early Planet Formation in Embedded Disks (eDISK)" aims to systematically study the origin of substructures in Class 0/I protoplanetary disks. As part of the program, we present observations of the Class 0 protostar GSS30 IRS3, which were conducted using ALMA Band 6 (1.3 mm) at a spatial resolution of 8 au. Observation targeted continuum and several molecular lines (12CO, 13CO, C18O, c-C3H2), which were all detected. While no apparent substructures such as gaps or spirals were observed, we noted a disk asymmetry. A fit in the visibility plane suggests that the asymmetry may be a sharp substructure. The 12CO traces the mass loss from the protostar disk, revealing a low-velocity molecular outflow with a mass loss rate of 6×105 M⊙ yr−1 and a high-velocity outflow component. Using the rotation curve analysis of the C18O isotopologue, which mainly traces the Keplerian disk, we derived a dynamical mass of 0.235 ± 0.039 M⊙ IRS3. A warp is detected in the C18O emission line, which we interpret it as infalling gas. The gas-to-dust size ratio for IRS3 was found to be 1.64, indicating no evolution of this ratio compared to Class II sources.