Analytical studies of collimated winds. IV. Rotating and collimated MHD outflows.

Details Analytical studies of collimated winds. IV. Rotating and collimated MHD outflows. Analytical studies of collimated winds. IV. Rotating and collimated MHD outflows.

Sep 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997a%26a...325.1099t&link_type=abstract

Astronomy and Astrophysics, v.325, p.1099-1114

Astronomy and Astrophysics

Astrophysics

25

Mhd, Plasmas, Sun: Atmosphere, Solar Wind, Stars: Atmosphere, Ism: Jets And Outflows

Scientific paper

This paper continues the study of the initial acceleration and final collimation of magnetized and rotating astrophysical winds, via analytical and exact steady MHD solutions, self-similar in the meridional direction. By prescribing the shape of the streamlines on the poloidal plane for a nonspherically symmetric gas pressure, related a posteriori to the density via a nonconstant polytropic index γ relationship (P{prop.to}ρgamma^), the main physical features of the outflowing plasma are deduced. Simple analytical relations show that cylindrical collimation and superAlfvenic terminal velocities can be attained asymptotically which depend on the rotation rate, the collimation distance from the base and the pressure gradient. If the plasma is overpressured at the flow axis, the pinching magnetic field can confine the jet, while if the gas is under-pressured at its axis, the centrifugal force cannot always counterbalance the pinching magnetic stress and inwards pressure gradient. Physically acceptable solutions are obtained by a numerical integration of the radial dependence of the MHD system from the subAlfvenic to the asymptotically collimated regions and by a smooth crossing of the Alfven critical surface. Two classes of solutions are found where either the flow speed increases monotonically to an asymptotic value, or it reaches a maximum value at an intermediate region. In the last case it is the toroidal magnetic field that collimates asymptotically the wind, while in the former the outflow of a slow rotator (respectively fast rotator) is collimated by the gas pressure (respectively by the magnetic field). The possible implications of these results on the modelling of astrophysical winds from slow and fast magnetic rotators are shortly discussed.

Affiliated with

Also associated with

No associations

Rating

Analytical studies of collimated winds. IV. Rotating and collimated MHD outflows. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Analytical studies of collimated winds. IV. Rotating and collimated MHD outflows., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Analytical studies of collimated winds. IV. Rotating and collimated MHD outflows. will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1222661