The ALMA early science view of FUor/EXor objects - III. The slow and wide outflow of V883 Ori

Abstract

We present Atacama Large Millimetre/sub-millimetre Array observations of V883 Ori, an FU Ori object. We describe the molecular outflow and envelope of the system based on the (CO)-C-12 and (CO)-C-13 emissions, which together trace a bipolar molecular outflow. The (CO)-O-18 emission traces the rotational motion of the circumstellar disc. From the (CO)-C-12 blueshifted emission, we estimate a wide-opening angle of similar to 150 degrees for the outflow cavities. Also, we find that the outflow is very slow (characteristic velocity of only 0.65 km s(-1)), which is unique for an FU Ori object. We calculate the kinematic properties of the outflow in the standard manner using the (CO)-C-12 and (CO)-C-13 emissions. In addition, we present a P Cygni profile observed in the high-resolution optical spectrum, evidence of a wind driven by the accretion and being the cause for the particular morphology of the outflows. We discuss the implications of our findings and the rise of these slow outflows during and/or after the formation of a rotationally supported disc.