Heays, A. N.Stark, GlennLyons, J. R.De Oliveira, N.Lewis, BrentonGibson, Stephen2026-01-152026-01-15A. N. Heays, G. Stark, J. R. Lyons, N. de Oliveira, B. R. Lewis & S. T. Gibson (2023) Ultraviolet photoabsorption in the B3Σ- − X3Σ- and C3Π − X3Σ- band systems of SO sulphur isotopologues, Molecular Physics, 121:17-18, e2153092, DOI: 10.1080/00268976.2022.21530920026-8976https://hdl.handle.net/1885/733804259High-resolution far-ultraviolet broadband Fourier-transform photoabsorption spectra of 32S16O, 33S16O, 34S16O, and 36S16O are recorded in a microwave discharge seeded with SO2. The (Formula presented.) and (Formula presented.) bands are observed or inferred in the (Formula presented.) –51,000 cm−1 (196 to 233 nm) spectral range. This is the first experimental detection of a (Formula presented.) level and of any of these observed bands in an S-substituted isotopologue. Additional measurements of (Formula presented.) provide a calibration of the SO column density. Measured band profiles are fitted to an effective-Hamiltonian model of coupled excited B 3Σ− and C 3Π states along with their predissociation linewidths and absorption band strengths. Electronic-state potential-energy curves and transition moments are deduced. The end result is a list of line frequencies, f-values, and dissociation widths describing the far-ultraviolet photodissociation spectrum of SO that is accurate enough for computing atmospheric photolytic isotope-fractionation. Linelists, and photoabsorption and photodissociation cross sections are available as supplementary data.AH was funded by the NASA Postdoctoral Program through the NASA Astrobiology Institute, by grant number 19-03314S of the Czech Science Foundation, and the European Regional Development Fund (ERDF/ESF) \u2018Centre of Advanced Applied Sciences\u2019 [grant number CZ.02.1. 01/0.0/0.0/16_019/0000778]. JRL acknowledges support from the NASA Exobiology program [grant #80NSSC19K0475 to Arizona State University].application/pdfen-AU© 2022 Informa UK Limited, trading as Taylor & Francis Group202310.1080/00268976.2022.21530922023-10-22