2 00 4 Application of MHD Disk Wind Solutions to Planetary / Protoplanetary Nebulae

Winds from accretion disks have been proposed as the driving source for precessing jets and extreme bipolar morphologies in Planetary Nebulae (PNe) and proto-PNe (pPNe). Here we apply MHD disk wind models to PNe and pPNe by estimating separately the asymptotic MHD wind velocities and mass loss rates. We discuss conditions which may occur in PNe and pPNe accretion disks that form via binary interactions. We show that the resulting winds can recover the observed momentum and energy input rates for PNe and pPNe. High accretion rates (M a ≈ 10 −4 M ⊙ yr −1) may be required in the latter case. We find that the observed total energy and momentum in pPNe can be recovered with disk wind models using existing disk formation scenarios. When combined with existing scenarios for accretion disk formation from disrupted stellar companions, our models may provide an explanation for the existence of high speed polar knots (FLIERS) observed in some PNe.