The file heffs.npy is a 5-dimensional matrix, with dimensions of n_tks x n_tss x n_tgps x 2 x 4
tks = Kinetic temperatures (K)
np.logspace(np.log10(0.1), np.log10(100.0), num=175)
tss = Spin temperatures (K)
np.logspace(np.log10(0.1), np.log10(100.0), num=175)
tgps = Gunn-Peterson optical depths
np.logspace(4.0, 7.0)
The indices within the last (2 x 4) submatrix stand for (continuum, injected) photons, and (net energy loss efficiency, energy loss efficiency to spins, \tilde{salpha}, effective color temperature (K)).
In practice, one only needs the net energy loss efficiency, \tilde{salpha} and effective color temperature.
The net energy loss efficiency is defined in Eq. (10), and, given a model for the continuum and injected Lyman-alpha fluxes, should be used in the temperature evolution as given by Eq. (18) of our paper at http://arxiv.org/abs/1804.02406
The dimensionless Wouthuysen-Field coupling coefficient \tilde{salpha}, and the effective color temperature T_{c,eff} are defined in Hirata C., (2006) astro-ph/0507102
The file toy_fluxes.dat contains tabulated values of the continuum and injected Lyman-alpha fluxes vs redshift for the toy star formation model described in our paper at http://arxiv.org/abs/1804.02406 (fluxes are in units of J_0 as given in our Eq.(6)). The model used to compute them is only a toy model, and the high-redshift star formation history is not known, so these values should only be used for illustrative purposes.
The quantities were computed from the solutions of the Fokker Planck equation, which is not a good description of the diffusion of Lyman-alpha photons at the lowest kinetic temperatures. Hirata (2006) tested the validity of the Fokker Planck equation down to tk = 2 K.