MHD Modeling of a Disk-Wind from a High-Mass Protobinary: the case of Orion Source I

B. Vaidya (1), C. Goddi (2,3)

1 - School of Physics and Astronomy, University of Leeds, Leeds LS29JT
2 - European Southern Observatory, Garching, Germany
3 - Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo, The Netherlands

Very long baseline interferometry (VLBI) observations of SiO masers in
Orion Source I has enabled for the first time to resolve the outflow from a high-mass protostar in the launch and collimation region. Therefore, Source I provides a unique laboratory to study mass-loss
and mass-accretion in a high-mass protostar.
We numerically simulate the dynamics of the disk-wind inside 100
AU from Source I.
This enables us to investigate the balance of different forces
(gravitational, magnetic, thermal) regulating gas dynamics in massive star formation. In this work, we adopt magnetohydrodynamic (MHD) disk-wind models to explain the
observed properties of the disk-wind from Orion Source I.
The central source is assumed to be a binary composed of two 10,$rm M_{odot}$ stars
in a circular orbit with an orbital separation of 7 AU. High resolution ideal MHD wind
launching simulations (which prescribe disk as a boundary) are performed using the PLUTO code. The simulations are allowed to run until a steady
state is obtained. MHD driven disk-wind provides a consistent model for the wide-angle
flow from Source I probed by SiO masers, reproducing the bipolar
morphology, the velocity amplitude and rotational profile, the
physical conditions, and the magnetic field strength.

Reference: MNRAS Letters
Status: Manuscript has been accepted