RADIO CONTINUUM DETECTION OF THE EXCITING SOURCES OF THE DG TAURI B AND L1551NE OUTFLOWS

摘要

The exciting sources of molecular outflows are characteristically associated with centimeter radio continuum emission, most probably originating in a partially ionized, collimated outflow. DG Tau B and L1551NE are two low-luminosity pre-main-sequence objects that have recently been found to be associated with molecular outflows. We have used 3.5 cm Very Large Array observations with angular resolution of 0.2" to detect compact radio continuum sources at both the positions of DG Tau B and L1551NE. The DG Tau B radio source has deconvolved dimensions (0.38" ± 0.02") x (0.22" ± 0.02"), and its major axis is aligned along a position angle of 298° ± 5°, coincident within a few degrees with the position angle of the axis of the optical and molecular outflows (～294°). This result suggests that we are observing the base of the collimated jet that powers the region, on scales of tens of astronomical units. A comparison of the widths of the radio and optical jets in this source supports this interpretation.