Posts for the month of May 2021

Jet figures and update

test

test

Dust in AstroBEAR - Update 2021/05/10

Objectives

  • Thesis stuff (main focus, still very busy with this, less progress on other stuff)
  • Debugging & Testing

Progress:

Some updates on the new problem setup: I've added a random distribution of clumps to the inner ejecta, and the 1D density profile from last time now looks like this in 2D.

As mentioned last time, I have no information about the temperature or velocity profile so I've made some guesses there. The temperature is less problematic, the velocity is a bit difficult. The idea is to find an initial velocity that will give us a forward shock at 2.5 pc after 330 yrs (suggested by observations).

I Started a simulation to test an initial velocity estimate but I've run into a problem with simulations taking ages. The current estimate for the simulation to finish is 8 years… I feel like I might have made a mistake during the setup. Some settings:

  • 32 initial cells with 8 AMR levels giving us the same resolution as the Slavin+2020 paper
  • HLLC solver and parabolic interpolation though if I go to HLL and constant it doesn't change much.

And some outputs from the simulation:

Potential error sources:

  • I removed the smoothing length h from the clumps because Slavin+2020 doesn't use that
  • scaling???
  • something else?

UPDATE: Advice helped, simulation is now running quickly! The expansion velocity is currently a bit fast so I will need to adjust that but it does form the forward shock close to the expected radius.

HEDP Experiments

Investigated role of density (similar to magnetic field)

Fiducial

Spitzer

spitzer (.25 density)


spitzer (.2 density)


spitzer (.15 density)


spitzer (.1 density)


Spitzer Resistivity

I added spitzer resistivity to AstroBEAR and it does appear to make a significant difference to the formation of the stand-off/stagnation shocks.

For the spitzer resistivity, I am using

And then the magnetic diffusivity (with units of cm2/s) as