ALMA detects a radial disk wind in DG Tau

TL;DR

This paper uses ALMA observations to identify a new radial disk wind component in DG Tau, revealing a steep-angle, low-velocity outflow likely related to photoevaporative processes near the disk surface.

Contribution

First detection of a radial disk wind in DG Tau using high-resolution ALMA data, expanding understanding of disk wind structures.

Findings

Discovery of a radial wind component at ~25° from vertical

Wind velocity of approximately 3.1 km/s

Wind likely related to photoevaporative processes

Abstract

Aims: We aim to use the high spatial resolution of the Atacama Large Millimeter/submillimeter Array (ALMA) to map the flow pattern of molecular gas near DG Tau and its disk, a young stellar object driving a jet and a molecular outflow. Methods: We use observations from ALMA in the J = 2 - 1 transition of 12CO, 13CO, and C18O to study the Keplerian disk of DG Tau and outflows that may be related to the disk and the jet. Results: We find a new wind component flowing radially at a steep angle (~25 deg from the vertical) above the disk with a velocity of ~ 3.1 km/s. It continues the trend of decreasing velocity for increasing distance from the jet axis ("onion-like velocity structure"). Conclusions: The new component is located close to the protostellar disk surface and may be related to photoevaporative winds.