X-Rays
The X-rays folder contains the X-rays data. The data is organized following the general hierarchical structure described in Suite folders.
We provide X-ray SIMPUT files for every halo above 10^12 M_solar for the 032 snapshot at z=0.05. Within each subdirectory containing a single simulation (e.g. LH_100) is a directory for the snapshot, of which there is currently only one snap_032. For every FoF halo above 10^12 M_solar, there is a SIMPUT fits file of the form:
IllustrisTNG.LH_100.snap_032.halo_010.100ks.z0.05.z_simput.fits
in the directory structure:
IllustrisTNG/LH_100/snap_032/
within which halos are ordered by the FoF group ID in the group finder catalogue (e.g. halo_010).
There exist a total of 160,693 halos:
5,939 IllustrisTNG_1P
2,003 IllustrisTNG_CV
342 IllustrisTNG_EX
75,340 IllustrisTNG_LH
5,157 SIMBA_1P
1,706 SIMBA_CV
70,206 SIMBA_LH
160,693 total
Each halo SIMPUT file consists of the main simput file, which is always the same size 11,520 bytes and represents the fits header, and a phlist file, which holds the photons and represents the fits data file:
IllustrisTNG.LH_100.snap_032.halo_010.100ks.z0.05.z_simput.fits
and
IllustrisTNG.LH_100.snap_032.halo_010.100ks.z0.05.z_phlist.fits
The pair of files, referred to as SIMPUT files, hold a Monte-Carlo-generated sample of photons produced by the pyXSIM software package that would be collected in an aperture of 3,000 cm^2 over 100,000 seconds for the object placed at z=0.05. The SIMPUT file format is the standard file format used in simulations of X-ray observations, and serves as the input into other software that generates mock observations for a specific telescope, such as SOXS and SIXTE.
It is helpful to have a background in X-ray simulation software to use these files. The limited collecting aperture in exposure time (3,000 x 100,000 = 3e+08 cm^2 s) means that mock observation software cannot simulate longer observations, but it is very rare for a telescope to observe deeper than this (e.g. eROSITA has an effective area of 2000 cm^2 and scans the sky to an average exposure of 2,000 seconds). While projected at z=0.05, it should be possible to scale the observation to be closer in the low redshift regime where received flux scales as z^-2. Note that the cosmology sets the angular size and luminosity distances, which in this case is affected by the Omega_M parameter.
Because the analysis of the SIMPUT files is rather complex, we also provide a reduced data format in the form of a single file in the base X-rays directory:
CAMELS.Xray.hdf5
This file has hold projected soft X-ray (0.5-2.0 keV) surface brightness profiles in units of ergs s^-1 kpc^-2 in 7 logarithmic radial bins ranging from 10-1,280 kpc. Each halo is in a hierarchical directory structure.