Warm dust emission near W75NIRS1: Evidence for multiple energetic outflows

This paper presents to 0."8 to 3 " resolution images of 1.3 and 3.3 mm continuum emission in the massive molecular outflow in W75 N. The mass of warm gas and dust near the center of the outflow is similar to 450 M. and represents approximately 45% of the core mass in the molecular cloud. Comparison of the distribution of warm dust emission with the locations of ultracompact H II regions indicates that the source VLA 3 probably contributes the most to the outflow dynamics. The location of VLA 2 near the 1 mm continuum peak and the presence of H2O masers suggests that this source may also contribute to the flow dynamics. The thermal jet source, VLA 1, has an estimated momentum rate that is 3 to 4 orders of magnitude less than that required to drive the large-scale CO outflow. If the ionized jet is the only outflow component, VLA 1 does not appear to be able to contribute significantly to the outflow energetics. Outflow parameter estimates that have been corrected for inclination and optical depth imply an outflow mass of more than a thousand solar masses and a mass outflow rate of similar to0.2 M. yr(-1). It is extremely unlikely that a single young stellar object can produce a flow of this magnitude; thus, several energetic outflows may be active.