Nested shells in the molecular wind from HL Tau: a possible origin in the disk sub-structures ?

The HL Tau young system includes the iconic ringed disk revealed by the first ALMA images, but also powerful outflows, in the form of a collimated atomic jet, a wide angle H2 wind and a conical CO wind. During the recent ALMA-DOT campaign, conducted at a resolution of 0."25 (about 40 au in HL Tau), we found that the CO wind shows a peculiar substructure in the velocity channel maps, that we interpret as a flow arranged in nested, layered shells with decreasing velocity with distance from the axis. This distribution is in line with the flow being an extended, inhomogeneous magnetized wind launched from an extended region of the disk, possibly up to about 90 au from the star. The molecular wind from various other targets show similar features than in HL Tau, but the latter is the only system in which disk rings are observed. Here, a preliminary analysis reveals a possible link between the footpoints of the wind shells and the location of the rings. This appears to support recent non-ideal MHD models (e.g. Suriano et al. 2019) according to which magnetic instabilities in the disk produce at the same time inhomogeneous layered MHD winds and rings/gaps in the disk, alternatively to the action of yet elusive protoplanets. The study of such winds in the millimeter range proves therefore to be crucial for the investigation of the planet formation process.