Early Planet Formation in Embedded Disks (eDisk): A first look at the Class 0 protostar IRAS16253-2429

Yusuke Aso, Nagayoshi Ohashi, John J Tobin, Jes K Jorgensen, Woojin Kwon, eDisk Team

The Class 0 protostar IRAS 16253-2429 is a candidate to have a central stellar mass close to the brown-dwarf (BD) mass limit (0.08 Msun); however, its stellar mass is controversial. Precise mass measurement is crucial to identify such a protostar that will help to understand the possible connection between the low mass end of star formation and BD formation. We thus observed this protostar as a part of the ALMA large program eDisk.
The 1.3 mm continuum emission at an angular resolution of 0.08” (11~au) shows a disk-like structure with a radius of ~20 au and a possible substructure. The C18O and 13CO J=2-1 lines trace the infalling envelope, previously reported. While the 12CO J=2-1 line traces the outflow perpendicular to the dusty disk, a high-velocity component (|V-Vsys|>2 km/s) of this line suggests the presence of a Keplerian disk. The SO J_N=6_5 - 5_4 line shows different velocity structures, implying presence of a ring around the Keplerian disk and a streamer from the east. Our result may provide a typical picture of protostars at the low mass end.

[Poster PDF File]