Meeting update

Summer school

Got to play a little with Gandalf SPH code and simulated the collapse of a singular isothermal sphere. Learned that python can process chombo hdf files, among lots of other cool astrophysics things.

Amira

Today I followed up with Christoph Federrath about the Amira vs. Disperse paper. I largely fleshed out the paper structure and figures and am excited to begin this project.

The goal of the paper will be to address the following 4 questions:

Do these different programs:

  1. Find the same # of filaments
  2. Find the same filaments
  3. Find "realistic" filaments
  4. Find "actual" filaments

For 3., Christoph's paper (link: ​http://www.mso.anu.edu.au/~chfeder/pubs/filaments/Federrath_filaments.pdf) talks about the differences in filament count between adding different physics to simulations. He finds that as you add more and more physics (turbulence, gravity, outflows), more and more filaments are formed in the simulations (no real surprise here). However, of greater interest is the fact that the average filament width is r=0.1 pc. He finds this across the board (irrespective of Disperse's sensitivity threshold and simulation resolution), so long as there is turbulence in the simulation. Since this matches observation (see Herschel findings), I called this "realistic" filaments. I think it would of interest if Amira also finds this result.

For 4., I described how we were throwing the idea around of creating a highly idealized simulation of 'definite' filaments and then feeding this through both Disperse and Amira. Do they both track all of the actual filaments we created? (I would imagine they would). Next we add some noise to the filaments progressively and watch if and when Disperse and Amira diverge in their findings.

I told him if he could send me the 2D CDM of one of his simulations with turbulence I could run it through Amira to get this started. I think we should think about how Disperse's 'persistence threshold' might be compared to parameters Amira uses and how to try to normalize the two programs the best we can..

Colliding Flows

Going to work on discussion and turbulent Jeans mass estimate these next couple of days

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