Emission spectra obtained from jet-cooled disulfur monoxide (S2O) molecules have been interpreted quantitatively by means of a U(2) Lie algebraic theory. Fluorescence accompanying selective excitation of the S2O C? 1A??X? 1A? (?*??) absorption system was dispersed under modest resolution, thereby permitting vibrational assignment of ground-state levels possessing up to 20 quanta of the ?2 S-S stretching mode. Aside from providing a convenient framework for analysis of recorded energy patterns, the algebraic treatment allows for straightforward calculation of multidimensional Franck-Condon factors and corresponding transition intensities. The emerging picture of S2O vibrational dynamics suggests that the X? 1A? potential surface is substantially more 'local' in character than the C? 1A? manifold.