Photodissociative absorption by H 2 + in the solar photosphere

Photoabsorption by systems of hydrogen atoms and protons in the solar photosphere is studied. Analytical formulas for the partial cross sections for photodissociation of the H 2 + molecular ion are derived for the cases of fixed vibrational-rotational energy levels and averaging over a Boltzmann distribution for a given temperature. The photoabsorption coefficients for bound-free and free-free transitions of H-H+ in the solar photosphere are calculated. These are compared with the absorption coefficients for photo-ejection of an electron from a negative hydrogen ion H− and free-free transitions of an electron in the field of a hydrogen atom H. Results can be applied to the Sun and hotter stars.