2017ApJ...851...64Z

We present state-resolved (electronic, vibrational, and rotational) cross sections and rate coefficients for the photodissociation (PD) of H₂⁺ and radiative association (RA) of H-H⁺. We developed a fully quantum mechanical approach within the nonrelativistic Born-Oppenheimer approximation to describe H₂⁺ and calculate the data for transitions between the ground electronic state 1sσ_g and the 2pσ_u, 2pπ_u, 3pσ_u, 3pπ_u, 4pσ_u, 4fσ_u, 4fπ_u, and 4pπ_u electronic states (i.e., up to H₂⁺n = 4). Tables of the dipole-matrix elements and energies needed to calculate state-resolved cross sections and rate coefficients will be made publicly available. These data could be important in astrophysical models when dealing with photon wavelengths (or radiation temperature distributions that are weighted toward such wavelengths) around 100 nm. For example, at these wavelengths and a material temperature of 8400 K, the LTE-averaged PD cross section via the (second electronically excited) 2pπ_u state is over three times larger than the PD cross section via the (first electronically excited) 2pσ_u state.