Early Planet Formation in Embedded Disks (eDisk): a first high-resolution view of molecular line emission toward the Class 0 protostar L1527 IRS

Merel van 't Hoff, John Tobin, Nagayoshi Ohashi, Jes Jorgensen, eDisk team

Studying the physical and chemical conditions of young embedded disks is crucial to constrain the initial conditions for planet formation. I will present the first high-resolution (25 au) ALMA observations of the young circumstellar disk around the Class 0 protostar L1527 taken as part of the Large Program eDisk (Early Planet Formation in Embedded Disks). The detected lines of 12CO, 13CO, C18O, H2CO, c-C3H2, SO, SiO, and DCN trace different components of the protostellar system, with a disk wind potentially visible in 12CO. The 13CO brightness temperature and the H2CO line ratio confirm that the disk is too warm for CO freeze out, with the snowline located at ~350 au in the envelope. Both molecules show potential evidence of a temperature increase around the disk-envelope interface. SO seems to originate predominantly in UV-irradiated regions such as the disk surface and the outflow cavity walls rather than at the disk-envelope interface as previously
suggested. Overall, these results highlight the importance of observing multiple molecular species in multiple transitions to characterize the physical and chemical environment of young disks, that is, the environment in which the first steps of planet formation take place.

[Poster PDF File]