Fine-structure transitions of the carbon isoelectronic sequence C, N+, and O2 + induced by collisions with atomic hydrogen

• Published in: Monthly notices of the Royal Astronomical Society Vol. 518; no. 4; pp. 6004 - 6010
• Main Authors: Yan, Pei-Gen, Babb, James F
• Format: Journal Article
• Language: English
• Published: 01-02-2023
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stac3471

Fine-structure transitions can be involved in various processes including photon absorption, charge transfer, and inelastic collisions between ions, electrons, and neutral atoms. We present fine-structure excitation and relaxation cross-sections for the collisions of the first few members of the carbon isoelectronic sequence (C, N+ and O2 +) with atomic hydrogen calculated using quantum-mechanical methods. For C, the scattering theory and computational approach is verified by comparison with previous calculations. The rate coefficients for the collisional processes are obtained. For N+ and O2 +, the transitions correspond to the lines [O iii] 52 μm, [O iii] 88 μm, [N ii] 122 μm, and [N ii] 205 μm, observed in the far-infrared in the local universe and more recently in high-redshift galaxies using radio interferometry. The influence of different potentials on the cross-sections and rate coefficients are demonstrated.