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Дата изменения: Tue Nov 10 12:42:00 1998
Дата индексирования: Tue Oct 2 12:02:15 2012
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Seminars

All-Moscow Seminar of Astrophysicists
(ASA)

The seminar is supported by the grant of Federal Programm "Integration"
annotation of talk
K.A.Levin, V.V.Mustsevoy, S.S.Khrapov (VolGU)
"The theory of jet-accretion flows"


1. The equilibrium models for conical jets and quasiceplerian gaseous disks confined by external pressure are constructed. It is assumed that disks have a constant half--thickness--to--radius ratio. In these models central massive object gravity field is taken into account also. It is shown that equilibrium physical parameters of such jets and disks are determined by ambient media conditions in a unique manner.

2. The linear stability is being investigated for following models: jet and disk in ambient atmosphire and model combining gaseous disk embeded in rather dense protostellar molecular cloud with bipolar conical jet perpendicular to the plane of disk. It is shown that the development of unstable acoustic and internal gravitational waves is possible. It is supposed that the axisymmetric perturbations can lead to formation of radiating jet knots and effective selfcollimation of conical jets. Our analysis shows that these perturbations lead to sinchronization of knots of oppositly directed jets and to intensive angular momentum transport also.

3. The results of nonlinear numeric simulation of supersonic matter ejection from protostar nucleus, surrounded by the atmosphere and rotating gaseous disk, are presented. It was actually shown, that such an ejection causes the atmospheric shock wave, creating expanding bubble, reaching the disk surface. Responding this bubble the shock wave arises in the disk, slightly inclined to its symmetry plane. Essential pressure reduction due to the fast bubble expansion calls inside complex reverse flow system, collimating gas to its symmetry axis, and generates around nucleus the fast rotating funnel, produced by the disk matter. The longliving toroidal vortex, which forms the Laval's jet, accelerating gas out of the protostar nucleus cocoon, out of inner disk area up to supersonic velocities and ejecting it along the symmetry axis, springs up in the inner domain of this funnel. The joint effect of two last reasons results in beginning of strongly collimated supersonic bipolar jet outflows with periodically located along--axis knots --- gaseous clumps. Such global flow structure is similar to morphology of spectacular protostar objects.