Clustered star formation and outflows in AFGL 2591

Abstract

We report on a detailed study of the water maser kinematics and radio continuum emission toward the most massive and young object in the star-forming region AFGL 2591. Our analysis shows at least two spatial scales of multiple star formation, one projected across 0.1pc on the sky and another one at about 2000 AU from a ZAMS star of about 38 M ̇. This young stellar object drives a powerful jet- and wind-driven outflow system with the water masers associated to the outflow walls, previously detected as a limb-brightened cavity in the NIR band. At about 1300AU to the north of this object a younger protostar drives two bow shocks, outlined by arc-like water maser emission, at 200AU either side of the source. We have traced the velocity profile of the gas that expands along these arc-like maser structures and compared it with the jet-driven outflow model. This analysis suggests that the ambient medium around the northern protostar is swept up by a jet-driven shock (>66 km s -1) and perhaps a lower-velocity (10 km s-1) wind with an opening angle of about 20°from the jet axis. © 2012. The American Astronomical Society. All rights reserved.