On the excitation of Io's atmosphere by the photoelectrons: Application of the analytical yield spectral model of SO₂

Spatially resolved HST/STIS observations of Io’s dayside equatorial atmosphere

“…Although in the absence of electron acceleration the impact of photoelectrons on Io's FUV auroral signature is expected to be small (cf. Bhardwaj and Michael, 1999), these observations suggest that a study of the contribution of the photoelectrons to the production of the emissions responsible for Io's NUV auroral signature as a function of local time may be warranted.…”

Photochemistry of a Volcanically Driven Atmosphere on Io: Sulfur and Oxygen Species from a Pele-Type Eruption

“…Ion chemistry will only be mentioned when it plays an important role in controlling neutral abundances. As with the models of Summers and Strobel (1996), we make the simplifying assumption that solar ultraviolet radiation is the only ionization source in the atmospherephotoelectron impact (e.g., Bhardwaj and Michael 1999) and bombardment by corotating jovian magnetospheric electrons (e.g., Kumar 1980Kumar , 1984Kumar , 1985 are ignored despite their obvious potential importance as ionization sources. The neglect of these ionization sources, however, should have relatively little effect on our predictions regarding the relative column densities of the neutral constituents (although the concentrations at high altitudes could be greatly affected).…”

Formation and Growth of Clusters of Sulfur Dioxide

“…An upper bound to λ may be obtained as λ D 1=s i n, where s i is the cross section for inelastic collisions between an electron and SO 2 and n is the number density at the expected structure and temperature. While the inelastic scattering cross section is obtained as the difference between the total and the elastic cross sections (Bhardwaj and Michael 1999), the number density is taken to be that of the solid at 143 K (0.030 mol cm ¡ 3 ) (Post et al 1952). The effect of elastic scattering is to increase the distance that the electron travels before escaping from the cluster.…”