Martin's update, 20 nov '12

TOKES ?

CRL 618

Jet sim running. New clump sim running
http://www.pas.rochester.edu/~martinhe/2012/19nov2012-b.pnghttp://www.pas.rochester.edu/~martinhe/2012/19nov2012-c.png

AGB r-2 radiation pressure force

Running tests on the global binary sims, i.e. 2 stars in the grid, 40 AU. http://www.pas.rochester.edu/~martinhe/2012/19nov2012-a.png

We talked about including a A* r-2 force term to the momentum equation to account for the wind's acceleration region. We need to decide on the strength of A.

the mom equation is:

v dv/dr = - 1/rho dp/dr - G m r-2+A r-2…(1)

it's useful to consider the relative forces: Gamma = A/Gm. So far we've used Gamma=1, but we want 0<Gamma<1.

Up: wind velocity / Mach. Bottom: wind density. VS. distance and Gamma values from Intro. to stellar winds, Lamers & Cassinelli. http://www.pas.rochester.edu/~martinhe/2012/16novA.jpg

Polodial magnetic collimation

This is essentially the same flow structure we find for strong fields in the lab, where the cavity is small and the plasma is immediately collimated into a jet, very close to the source (see panel 3 of Fig 4. in the article I sent you). Few things worth trying: (i) The interesting part of the flow in your case, seems to be under-resolved. Most of the computational box is not focusing on the interesting dynamics. (ii) Field lines not initially in the wind slide radially in the equatorial plane. However, if they are anchored in a disk the foot points should not move. This should give you field lines looking more like the ones on the inside of the cavity. If they are not anchored, then this is fine. (iii) You can lower the magnetic field or increase the wind mass loss rate, and should still get something like what you have now, but with a more elongated cavity.
Andrea: On the inside your flows look much more like the laboratory ones, here is an image from your simulations (colour map is density, vector is velocity, and lines is magnetic field lines).
http://www.pas.rochester.edu/~martinhe/2012/15nov-a.png

AGN jet trucnation

Dark spot in the weak AGN radio jet survives for 30kyr when the red giant crosses its axis! :)http://www.pas.rochester.edu/~martinhe/2012/15nov-b.png

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