Origin and kinematics of the eruptive flow from XZ Tau revealed by ALMA

TL;DR

This study uses high-resolution ALMA observations to reveal the detailed kinematics of eruptive bipolar flows from the XZ Tau stellar system, showing rotating, expanding structures and a collimated outflow from XZ Tau A.

Contribution

First high-resolution ALMA imaging of XZ Tau's eruptive flow, revealing its kinematic structure and origin from XZ Tau A with detailed molecular flow dynamics.

Findings

Revealed rotating and expanding molecular flow structure.

Identified a collimated bipolar outflow from XZ Tau A.

Measured the outflow's mass and energetics comparable to young brown dwarf outflows.

Abstract

We present high angular resolution ($\sim$0.94$"$) $^{12}$CO(1-0) Atacama Large Millimeter/Submillimeter Array (ALMA) observations obtained during the 2014 long baseline campaign from the eruptive bipolar flow from the multiple XZ Tau stellar system discovered by the Hubble Space Telescope (HST). These observations reveal, for the first time, the kinematics of the molecular flow. The kinematics of the different ejections close to XZ Tau reveal a rotating and expanding structure with a southeast-northwest velocity gradient. The youngest eruptive bubbles unveiled in the optical HST images are inside of this molecular expanding structure. Additionally, we report a very compact and collimated bipolar outflow emanating from XZ Tau A, which indicates that the eruptive outflow is indeed originating from this object. The mass (3 $\times$ 10$^{-7}$ $M_\odot$) and energetics (E$_{kin}$ $=$ 3 $\times$ 10$^{37}$ ergs) for the collimated outflow are comparable with those found in molecular outflows associated with young brown dwarfs.