Viewing angles used in "SDSS Photometry, Colors, and Mock Fiber Spectra" data catalogs
Andrej Obuljen
27 Aug '20
Hi,
A quick question about the viewing angles in the "SDSS Photometry, Colors, and Mock Fiber Spectra" data catalog, for TNG100-1.
Are the viewing angles same for all the galaxies and is there a quick way I can get these viewing angles?
As far as I understood, these angles correspond to HEALPix Nside=1 pixel centers, but I guess there are a couple of ways that one can orient and order the pixels, so I would just like to be sure that I get it right.
Thanks and bests,
Andrej Obuljen
Dylan Nelson
1 Sep '20
Hi Andrej,
In the actual HDF5 file, for the main dataset, there are several metadata attributes. You can see all these with e.g. h5ls -rv stellar_photometry.99.hdf5. The nProj and in particular projVecs contain the 3-vectors of the twelve directions. These are in the frame of reference of the simulation coordinates. (They are the same as the unmodified healpix Nside=1 points, as you say).
Hi,
A quick question about the viewing angles in the "SDSS Photometry, Colors, and Mock Fiber Spectra" data catalog, for TNG100-1.
Are the viewing angles same for all the galaxies and is there a quick way I can get these viewing angles?
As far as I understood, these angles correspond to HEALPix Nside=1 pixel centers, but I guess there are a couple of ways that one can orient and order the pixels, so I would just like to be sure that I get it right.
Thanks and bests,
Andrej Obuljen
Hi Andrej,
In the actual HDF5 file, for the main dataset, there are several metadata attributes. You can see all these with e.g.
h5ls -rv stellar_photometry.99.hdf5. ThenProjand in particularprojVecscontain the 3-vectors of the twelve directions. These are in the frame of reference of the simulation coordinates. (They are the same as the unmodified healpix Nside=1 points, as you say).Thanks a lot Dylan!
Bests,
Andrej