Previous abstract Next abstract
Session 7 - Molecular Clouds.
Display session, Wednesday, January 07
Exhibit Hall,
We present results of the first VLBA study of the 43 GHz SiO masers in the Orion BN/KL region. Maser spot positions have been measured with a characteristic accuracy of less than 0.5 AU. The distribution of the emission strongly suggests that the masers trace the walls of two opposing cones, as in a bipolar outflow from a central object. The flow is probably centered on a known radio continuum source in the region, and it is inclined to the line of sight, with the northwestern cone redshifted by about 20 km\,s^-1 with respect to the southeastern cone. Previous models of the region, based on observations with at least 500 times lower angular resolution attribute that maser features to a rotating and expanding disk. Nearby water masers may trace a warm dusty disk that is orthogonal to the bipolar outflow.