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COMMON ENVELOPE SIMULATIONS

New Work

CE Jet (with Amy)
Continued AGB run on stampede 2

CE Jet Movies

Movies are in the frame of reference of secondary, with secondary at the center.

Here are the old notes on CE Jets.

Here is the Xsede proposal.

Below we compare two test runs, identical except that the jet is turned on in Run 014, whereas the jet is turned off in Run 015. The jet model is adapted from Federrath et al. 2014.

For both Run 014 and Run 015, parameters are as in the fiducial run 143 (Model A of Paper 1) except:
Base resolution = 64³;
Max AMR level = 4;
Region of maxlevel refinement = sphere of radius 57 Rsun around particle 1 (primary radius is 48 Rsun);
Size of smallest resolution element = 1.1 Rsun.

For Run 014, the jet parameters are:
Jet mass loss rate = 0.02 Msun/yr;
Jet velocity along jet axis = 10³ km/s;
Jet temperature = 3000 K;
Jet collimation half opening angle = pi/12;
Jet radius = 64 grid cells.

Other jet runs are similar to Run 014 except with certain differences, mentioned below.

Comparison of Run 015 with Run 014
Density, face-on (left = no jet, right = jet)
Density, edge-on through particles (left = no jet, right = jet)
Density, edge-on view from particle 1 (left = no jet, right = jet)

Comparison of Run 015 with Run 016 (like Run 014 but 100 times the jet mass loss rate)
Density, face-on (left = no jet, right = superstrong jet)
Density, edge-on through particles (left = no jet, right = superstrong jet)
Density, edge-on view from particle 1 (left = no jet, right = superstrong jet)

Comparison of Run 015 with Run 017 (like Run 016 but with ½ the jet radius)
Density, face-on (left = no jet, right = superstrong jet with small radius)
Density, edge-on through particles (left = no jet, right = superstong jet with small radius)
Density, edge-on view from particle 1 (left = no jet, right = superstong jet with small radius)

Comparison of Run 014 with Run 016
Density, face-on (left = jet, right = superstrong jet)
Density, edge-on through particles (left = jet, right = superstrong jet)
Density, edge-on view from particle 1 (left = jet, right = superstrong jet)

Comparison of Run 016 with Run 017
Density, face-on (left = superstrong jet, right = superstrong jet with small radius)
Density, edge-on through particles (left = superstrong jet, right = supersrong jet with small radius)
Density, edge-on view from particle 1 (left = superstrong jet, right = superstrong jet with small radius)

Comparison of Run 014 with Run 018 (like Run 014 but with 1/100 of jet radial velocity
Density, face-on (left = superstrong jet, right = superstrong jet with low velocity)
Density, edge-on through particles (left = superstrong jet, right = supersrong jet with low velocity)
Density, edge-on view from particle 1 (left = superstrong jet, right = superstrong jet with low velocity)

Comparison of Run 018 with Run 019 (like Run 018 but with ½ the jet radius, like Run 017 but with 1/100 of jet radial velocity)
Density, face-on (left = superstrong jet with low velocity, right = superstrong jet with small radius and low velocity)
Density, edge-on through particles (left = superstrong jet with low velocity, right = superstrong jet with small radius and low velocity)
Density, edge-on view from particle 1 (left = superstrong jet with low velocity, right = superstrong jet with small radius and low velocity)

Comparison of Run 017 with Run 019
Density, face-on (left = superstrong jet with small radius, right = superstrong jet with small radius and low velocity)
Density, edge-on through particles (left = superstrong jet with small radius, right = superstrong jet with small radius and low velocity)
Density, edge-on view from particle 1 (left = superstrong jet with small radius, right = superstrong jet with small radius and low velocity)

Comparison of Run 015 with Run 019
Density, face-on (left = no jet, right = superstrong jet with small radius and low velocity)
Density, edge-on through particles (left = no jet, right = superstrong jet with small radius and low velocity)
Density, edge-on view from particle 1 (left = no jet, right = superstrong jet with small radius and low velocity)

Notes on CEJet runs

Notes on the results
1. The late emergence of the jets with lower radius is hard to comprehend. It seems like one quadrant emerges first and then spreads to cover all 4 quadrants.
2. It appears that the mass loss rate needs to be quite large or the radial velocity quite small to get an obvious effect on the morphology, but that's also because the radius is too large. We need to understand the dependence on jet radius and whether the effects we're seeing are physical or numerical.
Notes on the simulations
1. Number of resolution elements per softening radius is only 2.2, leading to numerical instability of primary core region.
2. Particle orbits are not reliable as their separation a increases even in the no jet case, due to insufficient resolution.
3. Partly for these reasons, stopped movie around t=7 days.
4. The simulations take a few hours to run up to this time with 115 cores on bluehive. Increasing the max AMR level by 1 or 2 should be possible.
5. Also, we should start to move away from uniform resolution inside a sphere and toward full AMR.
6. It would be good to introduce a tracer into astrobear for the jet material
7. The ambient density and pressure could be lowered considerably. (I realized that the whole reason for the high ambient, namely to stabilize the outer layers, is not really relevant because that numerical instability that we saw when the scale height at the surface was not highly resolved was likely mostly due to grid effects when the star was fixed on the grid (e.g. during the damping run). Now we no longer do damping runs anyway. Amy and I have seen that the surface of the primary appears stable, even when the initial separation is increased and for much lower resolution than the fidicial run 143. The lesson seems to be that these pesky grid effects mostly go away when the star moves over the grid since errors accumulate randomly rather than uni-directionally. Bottom line is we should be able to get away with much lower ambient pressure and density, alleviating various headaches…)
8. Currently, it is not possible to do restarts from the fiducial run since they used a different version of astrobear and the chombos are not quite compatible (the jet feedback module contains new outputs to the chombo that were not present in the previous version of astrobear used to run the fiducial CE run 143).
9. The above item is not really a problem. Anyway, we should do a new fiducial run without jets, with low ambient, more efficient refinement strategy and bigger box.
10. We should also try starting the secondary from farther out, as this case is likely to be interesting.
Notes on the analysis
1. It would be good to plot planes parallel to the orbital plane (say 10 Rsun above it) to see the jet cross-section.
2. Velocity vectors would be useful.
3. Plots of normalized energy density (blue/red for bound/unbound) would be helpful.
4. Put circular contour with radius=jet_radius around point particle 2 for reference.

Next steps

Test CEJet module, e.g. is it adding mass to the grid at the correct rate (Amy).
Continue to experiment with CEJet module on bluehive.
Continue to run AGB CE simulation on stampede and plot results.
Begin writing post-processing to obtain forces from full resolution data sets of Run 143 (fiducial), 149 (half secondary mass of fiducial) and 151 (fourth secondary mass of fiducial), as serial VisIt cannot handle the data sets (parallel VisIt is another option but we weren't successful when we tried to get it to work—anyway postprocessing means that in later simulations these quantities could be calculated on the fly, which would be useful).

astrobear