They show it on the original Illustris data, and my script does work if I use that. But when switching to TNG, no images are ever found. Are they still available? Or maybe stored differently/called something else? If not, is there a way to get an equivalent mock observation myself from TNG?
Thanks!
Dylan Nelson
18 Mar '22
This exact processing (with the SUNRISE code) is unfortunately not available in any TNG simulations.
But there is a similar dataset (with the SKIRT code), you can read the details and download in a very similar way.
I notice that in the original Illustris there were images of entire halos, but in TNG, only of subhalos. I'm trying to compare to observations of post-merger galaxies, which often have off-center features/satellites, etc. Is there a danger of missing, say, a piece of the original subhalo which was thrown away from the main galaxy, but is still interacting with it, because it is now technically a different subhalo?
Dylan Nelson
12 Apr '22
You are exactly right - by construction, if the images are made only of a subhalo, then they will be excluding the stars of any nearby companions, since these will belong to different subhalos.
You could check this for a few cases using the "Visualize Galaxies" tool. Under "render method", the option "sphMap_subhalo" includes only particles of that subhalo, while "sphMap" includes all the FoF halo particles (like some of the original Illustris mocks). If you find a merger in progress, and flip back and forth between these two, you can see the impact.
If you want to make stellar mocks, including all halo stars, in TNG, then you would probably want to (need to) make these.
Jacob Morgan
12 Apr '22
That tool might actually be just what I want! But I would need an automated way to generate/download the images. Are these the same thing as they visualizations listed under 'API Reference-->FoF Halos' on the API page? If so I think I could construct 'vis_query' and go from there. But is there a way to also use the same color bar for stellar column density in all such images? Or does it already do that?
Dylan Nelson
13 Apr '22
Yes that webpage is just an interactive way to use the API, you can get the same results from the API as you say. You can use the min and max arguments to set the colorbar limits.
Jacob Morgan
15 Apr '22
Thank you! And last question (I think):
When making the halo visualization, it looks like it has 0, 1 for the "projection axis" by default-- are all stellar-mocks type data products (such as those made with the SKIRT code) x-y projections unless I specify otherwise when making them?
Hey there! I was hoping to download some pre-rendered stellar mock images from TNG100 or TNG50, following the API tutorial here:
https://www.tng-project.org/data/docs/api/ (Task 10 basically does what I want)
They show it on the original Illustris data, and my script does work if I use that. But when switching to TNG, no images are ever found. Are they still available? Or maybe stored differently/called something else? If not, is there a way to get an equivalent mock observation myself from TNG?
Thanks!
This exact processing (with the SUNRISE code) is unfortunately not available in any TNG simulations.
But there is a similar dataset (with the SKIRT code), you can read the details and download in a very similar way.
Thank you for the response!
I notice that in the original Illustris there were images of entire halos, but in TNG, only of subhalos. I'm trying to compare to observations of post-merger galaxies, which often have off-center features/satellites, etc. Is there a danger of missing, say, a piece of the original subhalo which was thrown away from the main galaxy, but is still interacting with it, because it is now technically a different subhalo?
You are exactly right - by construction, if the images are made only of a subhalo, then they will be excluding the stars of any nearby companions, since these will belong to different subhalos.
You could check this for a few cases using the "Visualize Galaxies" tool. Under "render method", the option "sphMap_subhalo" includes only particles of that subhalo, while "sphMap" includes all the FoF halo particles (like some of the original Illustris mocks). If you find a merger in progress, and flip back and forth between these two, you can see the impact.
If you want to make stellar mocks, including all halo stars, in TNG, then you would probably want to (need to) make these.
That tool might actually be just what I want! But I would need an automated way to generate/download the images. Are these the same thing as they visualizations listed under 'API Reference-->FoF Halos' on the API page? If so I think I could construct 'vis_query' and go from there. But is there a way to also use the same color bar for stellar column density in all such images? Or does it already do that?
Yes that webpage is just an interactive way to use the API, you can get the same results from the API as you say. You can use the
minandmaxarguments to set the colorbar limits.Thank you! And last question (I think):
When making the halo visualization, it looks like it has 0, 1 for the "projection axis" by default-- are all stellar-mocks type data products (such as those made with the SKIRT code) x-y projections unless I specify otherwise when making them?
Thank you for your time!
Thank you so much for your time!