The photodetached electrons were analyzed using a velocity-map imaging (VMI) assembly described elsewhere. In the present experiments, the three VMI electrodes were kept at -330, 0, and +900 V, respectively, projecting the photodetached electrons in the direction perpendicular to the ion and laser beams. At the end of a 15 cm long electron flight tube, the electrons were postaccelerated into a 40 mm diameter dual microchannel plate detector coupled to a P47 phosphor screen (Burle Inc.). Images from the screen, fiber-optically coupled to an outside window, were captured using a charge-coupled device camera (Roper Scientific, Inc.). Photoelectron images of SO  were taken at 532 and 355 nm using the second and third harmonics, respectively, of a Spectra Physics Lab-130-50 Nd:YAG laser (25 mJ/pulse and 5 mJ/pulse, respectively, ~6 ns pulse duration). The 611 nm light was generated by the fluorescence of Rhodamine 640 dye in an ND6000 dye laser pumped by Surelite II-20 Nd:YAG (Continuum, Inc.). In all measurements, the (linear) laser polarization direction was set parallel to the imaging detector surface.