Fluorescence Efficiencies of the N2+ cation

This archive contains fluorescence efficiencies ('g-factors') for the N2+ cation. The .tar.gz file contains three files/directories, and totals around 2.9 gigabytes of data when uncompressed: A READ_ME file describing the contents, Computed fluorescence efficiencies of N2+ in fluorescence equilibrium, stored in /fluorescence_equilibrium_data/ Computed fluorescence efficiencies of N2+ in the time-average formalism, stored in /time_average_data/, described in the associated manuscript, for different values of the lifetime 'tau.' The value of tau used for each file is given in the filename in units of seconds. The data in each directory are reported in two forms: (1) in units of photons/s/mol, and J/s/molecule. The directories contain both raw line-by-line fluorescence efficiencies ('gfactors'), and band luminosities, produced by summing of the g-factors of the transitions in each band. The first columns of each file contain identifying information for the transition/band, followed by the gfactor or band luminosity, as a function of heliocentric velocity from -100 km/s to +100 km/s in steps of 1 km/s. The first row of each file contains a header describing the contents and units of each column. The velocity grid can be generated (in Python) as vel_grid = np.linspace(-100,100,201). The underyling fluorescence model was constructed as follows: Within the X2Sigma state, vibrational levels from v=0 to v=7 were included. Within the A2Pi state, vibrational levels between v=0 to v=5 were included. Within the B2Sigma state, vibrational levels between v = 0 to v = 6 were included. All rotational states up to N = 50 were included. Experimentally-determined constants were combined with Einstein A coefficients for the B-X bands (computed from the constants reported in Ferchichi et al 2022) and the A-X bands (sourced from Ventura et al 2024) in the PGOPHER program of Western et al 2017 to produce a line-list of N2+. The line list is post-processed into transition and energy level files compatible with the Florpy code described in Bromley et al 2021. The fluorescence equilibrium fluorescence efficiencies, at a heliocentric distance of 1 au, were computed by first initiliazing the level populations of N2+ to a Boltzmann distribution at T = 276 K, and propogated in time until equilibrium was achieved. The resulting level populations were used to compute fluorescence efficiencies in energy units (J/s/molecule) and photon units (photons/s/molecule). The g-factors and band luminosities scale smoothly with heliocentric distance, and can be scaled to a given distance by multiplication of the factor 1/rh^2 where rh is in astronomical units. The time-average data, in both energy and photon units, are reported on the same velocity grid as the equilibrium data. Here the populations were initialized the same as fluorescence equilbrium, then solved as a function of time. These data are then averaged over a lifetime, tau (given in the filenames of the time_average_data files), on the same grid of velocities. The computed data are stored in plain-text, tab-delimited files, and the first value in each column contains a header describing the column's contents. Each file contains these quantities, in energy or photon units depending on the filename, for either the B-X (First Negative) or A-X (Meinel) bands of N2+. Visual inspection of the contents can be achieved with Microsoft Excel or other spreadsheet programs. The data can also be read into Python arrays using standard NumPy or Pandas functions.