Hydromagnetic winds from accretion disks

We present a hydromagnetic wind model for molecular and ionized gas outflows associated with protostars. If the luminosity of protostars is due to accretion, then centrifugally driven winds that arise from the envelopes of molecular disks explain the observed rates of momentum and energy transport. Ionized outflow originates from disk radii r ≤ 1015 cm inside of which Ly-continuum photons from the protostellar accretion shock are intercepted. Observed molecular outflows arise from the cool disk envelope at radii 1015 ≤ r ≤ 1017 cm. The mass-loss rates of these two component outflows are [Formula: see text] and [Formula: see text]. These winds solve the angular-momentum problem of star formation. We propose that the collimation of such outflows is due to "hoop" stresses generated by the increasingly toroidal magnetic field in the wind and suggest that the structure of the underlying disks makes self-similar solutions for these outflows likely. Finally, we apply this analysis to other accreting systems such as cataclysmic variables.

Hydromagnetic winds from accretion disks Journal Articles