The effects of winds on disk and planet formation

To constrain the planet formation process, it is particularly important to study the innermost regions of disks where planets are believed to form. However, these are also the regions where magnetohydrodynamic winds are launched. Until very recently, we have not been able to put observational constraints on what is really happening on the smallest scales and to what degree winds are capable of affecting the disk evolution, and consequently - planet formation. ALMA has, in this regard, revolutionized the field.

In the YODA (Young Outflows and Disks with ALMA) project, we are observing young protostellar regions with ALMA in its largest configurations to spatially and kinematically resolve young disk structure, outflow launching, and star- and planet-formation. The first resolved images of wind launching from a disk were reported towards the young source TMC1A (P. Bjerkeli, et al., 2016, Nature, 540, 406), where we also report evidence of early grain growth (D. Harsono et al., 2018, Nature Astronomy) and that the bulk of the planet forming gas is being delivered to the disk unaltered (D. Harsono et al. in review.). We also studied the B335 system, which because of its lack of an observed Keplerian disk is believed to be either very young or undergoing strong magnetic braking. The observations allow us to constrain the ejection process on the smallest scales (Bjerkeli et al., 2019, A&A, 52,1), as well as accretion from the envelope on all relevant scales (Bjerkeli et al. in prep.).