Presentation #114.01 in the session “High-mass Star Formation”.
Accretion-powered magneto-centrifugally launched jets, winds and outflows are often the first indications that a star is being born. As the protostar is deeply embedded in a dusty, natal core envelope, it is often easiest to infer protostellar properties from the light that escapes lower density outflow cavities and from the kinematic signatures of fast outflowing gas. Therefore, understanding the outflows from embedded protostars can reveal important information about the star formation process itself. We perform 3D magneto-hydrodynamic simulations of the outflow driven by a protostar forming from a 60 solar mass core. The input mass and momentum of the outflow are evolved according to a theoretical model of protostellar growth and with a spatial distribution expected of a self-similar disk wind. We follow the growth of the protostar from a very early stage with a low initial mass until its near final state and thus investigate the self-consistent global evolution of the outflow, especially tracking the velocity and momentum distribution of the escaping gas and the opening angle of the low density outflow cavity. We find that, until the protostar reaches about 4 solar masses, the outflow remains very narrow, i.e., with a half-opening angle of <10 degrees. As the protostar grows to larger masses, the outflow grows in both width and strength. We find that much of the collapsing envelope becomes entrained in the outflow and we discuss the overall star formation efficiency from the core.