Public Data Access Overview / Discussion Forum

Hi, thanks for approving the account. I'm trying to download images of simulated galaxies, but the fits files seem to contain something different. The headers say:

"COMMENT This HDU contains the camera parameters. The image contains the solid an COMMENT gle subtended by the individual pixels."

For example I downloaded a fits with the following command:

wget --content-disposition --header="API-Key: bfe96b322c52c5ec7957699fc86077b9" "http://www.illustris-project.org/api/Illustris-1/snapshots/135/subhalos/437252/stellar_mocks/broadband.fits"

And the image looks like a radially declining circular shape with values of 2e-11.

Any ideas as to what I'm doing wrong?

Thanks a lot for the help

Guillermo

Hi Guillermo,

Someone ran into this once before, and the answer was just that you are looking at the wrong part of the FITS file. In Python e.g.

file = fits.open('broadband_321411_135.fits')
file.info()

data = file[14].data // this one contains all the 35 bands in sub-arrays

data1 = np.array(data[i])

Thanks Dylan,

I have now figured out the fits file extension structure. The "Supplementary Data Catalogs" section in the Data Access section talks about mock stellar images being available at different snapshots (i.e. redshifts) for individual galaxies. If I understand well from looking at the fits files and at Torrey et al. 2015, these only have the z=0 images. Is there a way to get a hold of the images at higher redshifts? We are working on the galaxy evolution chapter for the GMT Science Book, and I would like to simulate some illustris galaxies as would be observed by the GMT to produce a figure for this document.

Thanks!

Hi Guillermo,

The other data mentioned is also available to download for those snapshots, e.g. the broadband FITS file of the central subhalo of halo #100 at z=1 in Illustris-1 is available at

http://www.illustris-project.org/api/Illustris-1/snapshots/z=1/subhalos/96174/stellar_mocks/broadband.fits

Dylan