Bipolar outflow in B335 - The small-scale structure

The young stellar object in B335 is studied with interferometric observations to determine the scale of the outflow collimation and the structural attributes of the outflow and the disk. Observations with high angular resolution are described that address the (C-12)O (J = 1-0) and 2.6-mm-continuum emission. A biconical outflow structure is identified in the (C-12)O high-velocity emission that is focused with approximately 1000 AU of its origin. A 2.6-mm-continuum source with a peak flux of approximately 80 mJy identified within about 4 arcsec of the outflow center indicates that a very dense field of n(H2) of more than about 10 exp 8/cu cm surrounds the object. The dense material is thought to both drive and collimate the outflow, and a model is proposed that accounts for the increase in velocity away from the center observed near the origin. The dynamical model describes the velocity field of B335's outflow with acceleration and deceleration in regions of certain ambient density gradients.