Effective recombination coefficients for N II lines at nebular temperatures and densities

Abstract

We calculate effective recombination coefficients for the formation of selected lines of N II. New photoionization data are computed which accurately map the near threshold resonances and are used to derive recombination coefficients for principal quantum numbers, n ≤ 15, including radiative and dielectronic recombination. Cascading from higher states is included, allowing for the effects of finite electron density in a hydrogenic approximation. The effects of population in the excited states of the recombining ion are investigated.