An Envelope Streamer Feeding a Ringed Disk in the Class I Protostellar Phase Dominique Segura-Cox MPE, Munich, DE
Ringed protoplanetary disks, in the Class II phase of low-mass star formation when the envelope has mostly dispersed, have been found in abundance in recent years with high-resolution ALMA observations. These ringed disks have been often interpreted as evidence of planet formation, caused by planetesimal-disk interactions. I will present ALMA observations of a younger embedded Class I protostar which has a ringed dust disk (5 au resolution data) as well as a larger-scale infalling streamer of gas 1500 au in length from the envelope to the disk (100 au resolution data). The dust rings are the least-evolved example of rings in a protostellar disk known to date, indicating that stable zones of grain growth---required for the first steps of planet formation---are already in place during the early embedded phase of star formation. Further, these first steps of planet formation occur while the envelope continues to accrete onto the disk, likely influencing the disk composition and dynamics until the envelope is fully dissipated. Our work highlights the need for both disk and envelope scale observations to understand disk dynamics in the young embedded phases of protostars.
Collaborators: J. Pineda, MPE, DE A. Schmiedeke, MPE, DE P. Caselli, MPE, DE B. Zhao, MPE, DE I. Stephens, CfA, US M.J. Maureira, MPE, DE M. Fernandez-Lopez, IAR, AR L. Looney, UIUC, US Z.-Y. Li, UVa, US W. Kwon, KASI, KR L. Mundy, UM, US	Suggested Session: Cores2Disks