Massive Protostellar Outflows: Are they Different from Low Mass Outflows?


Debra Shepherd

NRAO

 
Abstract
Molecular Outflows in the form of wide-angle winds and/or well-collimated jets are associated with young stellar objects of all luminosities. Because outflows provide a fossil record of the mass-loss history of the system, they can be useful tools to help understand the underlying formation processes of young stars. Independent studies suggest that there is a strong link between accretion and outflow for a wide range of source luminosity (Lbol = 0.3 to 10^5 Lsun). For low-mass T Tauri stars, the dynamics are governed by the presence of linked accretion and outflow where magnetic stresses control the balence between inflow and outflow and determine the outflow structure far from the protostar. There is also reasonable evidence that accretion-related processes are responsible for generating molecular flows from early B protostars (Lbol = 10^3 to 10^4 Lsun). Beyond Lbol = 10^4 Lsun, O stars generate powerful wide-angle, ionized winds that dramatically affect outflow morphology and even call into question the relationship between outflow and accretion. I will review the known properties of outflows from young, massive OB stars and discuss implications for possible differences between low-mass and massive star formation.