Creating Maps of Group Values in coordinate diagrams

Alexandres Lazar
  • 1
  • 23 Jun '17

Hi Dylan,

I am wanting to know if it is possible to create maps like a "cosmic-web" or "heat maps" from values in the Group catalogs instead of information from snapshots? Primarily in a coordinate diagram for the entire simulation box? Similar to that like the example data page under "Snapshots"

If so, would I be able to create high resolution images for temperature, SF metallicity, gas metallicity and so on like in these? Or would I just be better of using numpy modules like Histogram2d and so on?

Screen Shot 2017-06-22 at 7.10.40 PM.png

Would something like this cost a lot or processing power?

Thank you in advance.

Dylan Nelson
  • 25 Jun '17

Hi Alexandres,

If you want to visualize/project the group catalog objects, instead of the particle objects, this is certainly possible. You could get a quick view of the cosmic web / large scale structure of the box with a Histogram2D approach like in the tutorial, but replacing particle Coordinates with e.g. the group catalog SubhaloPos and SubhaloMass.

On the other hand, these image examples are definitely made using individual DM/gas particles. We haven't released any visualization tools for Illustris data, but if you are interested in using some package or learning more about various types of visualizations, you can maybe look at "Py-SPHViewer", "Splash", "Pynbody", "yt", "PMViewer", etc.

Alexandres Lazar
  • 4
  • 25 Jun '17

Thank you for the response!

Is their a way for me get temperature just from the group catalog? or are those values only limited to the snapshots?

Dylan Nelson
  • 26 Jun '17

You could calculate the virial temperature for each halo, and then bin this.

Maybe look at binned_statistic_2d. This would allow you to make a "map" of the mean virial temperature of halos falling into each bin, which would then make a pretty interesting image. I'd be curious to see!

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