Excitation of C II] 2326, O III] 1644 and other Semi-Forbidden Emission lines, in Quasars

Accurate collision strengths for the semi-forbidden transitions |C⁺, N²⁺ 2s²2p ²P⁰-2s2p2 4P| , and |N⁺, O²⁺ 2s²2p2 3P-2s2p3 5S⁰| , have recently been calculated using the close coupling approximation and allowing for configuration interaction. Effective collision strengths are presented for these transitions as a function of electron temperature Te . The significance of these results, for various quasar models is discussed.