equilibrium_abundances

The equilibrium abundances data files tabulate the equilibrium chemical abundances as a function of temperature, density and metallicity. These are used when the gasVariables.ForceEqOn parameter is set to 1.

We have included several examples of these pre-computed equilibrium tables, for different model assumptions, including for the COLIBRE model for the radiation field, shielding and dust depletion (Ploeckinger & Schaye 2020), both with only hydrogen and helium in the network (EqAbundancesTables/colibre_HHe) and with the full network but only at high metallicities (EqAbundancesTables/colibre_iso_full.hdf5), for the redshift zero extragalactic UV background from Haardt & Madau (2001), but with and without shielding (EqAbundancesTables/HM01/EqAbundances_HM01.hdf5 and EqAbundancesTables/HM01/EqAbundances_HM01_noShield.hdf5, respectively), and for the redshift zero extragalactic UV background from Haardt & Madau (2012) without shielding (EqAbundancesTables/HM12/EqAbundances_HM12_noShield.hdf5).

Note that, if you do load an equilibrium abundance table, the number of species in the table needs to match the number of species that are included in the CHIMES network, for example if you have switched off individual elements.

New equilibrium abundance tables can be created using the chimes-driver.py script. See the CHIMES Driver section for more details.

The data arrays included in the equilibrium abundance tables are described in detail below.

Data Array Description
Abundances
A 4-dimensional array of size (N_Temperatures x N_Densities x
N_Metallicities x N_species), giving the abundance of each
species as a function of temperature, density and metallicity. The
abundances are stored as log10(n_i / n_elem), where n_i is the
number density of the ion or molecule, and n_elem is the total
number density of the corresponding element.
TableBins/N_Temperatures
The number of temperature bins.
TableBins/N_Densities
The number of density bins.
TableBins/N_Metallicities
The number of metallicity bins.
TableBins/N_species
The number of species included in the network.
TableBins/Temperatures
A 1-dimensional array of length N_Temperatures containing the
temperature bins, given as log10(T [K]).
TableBins/Densities
A 1-dimensional array of length N_Densities containing the density
bins, given as log10(nHtot [cm^-3]).
TableBins/Metallicities
A 1-dimensional array of length N_Metallicities containing the
metallicity bins, given as log10(Z / Zsol), where Zsol = 0.0129 is the
solar metallicity.