Spectrum Of Io Research Articles

On the surface composition of Io

The wavelength dependence of the reflectivity of Io indicates the presence of two materials on the surface of this satellite of Jupiter. These materials are sulfur and an unspecified material ( R 1) which shows a wavelength dependence of its reflectivity for 0.3 μm < λ < 1.0 μm similar to the non-H 2O frost spectrum of the rings of Saturn. A 60/40 admixture of these two spectra matches the observed reflection spectrum of Io from 0.3μm–3 μm, if the spectrum of R 1 is featureless for λ > 1 μm. Sulfur will give rise to a posteclipse brightening. The variation with wavelength of the temperature dependence of the reflectivity of sulfur will allow an observational confirmation of the presence of sulfur on Io. The material R 1 should show a large geometrical albedo. The translucency of sulfur is consistent with the polarization-phase curve to Io. The material R 1 is also required to be translucent. The thermal conductivity of a cooled sulfur powder under vacuum was measured and found to agree with the value determined for the upper layer of Io from observations at 10 μm. It is shown that this agreement is not necessarily meaningful.

The Spatial Extent of Sodium Emission around IO

The sodium D emissions associated with Io's spectrum also originate in a large volume of space surrounding the satellite, extending more than 10 arc sec in radius. Although this region extends well beyond the equilibrium point between Jupiter and Io, no emission torus has been detected around Jupiter. The emission, however, appears to be stronger close to Io's orbital plane and especially on the Jovian side of Io. Resonant scattering is a viable excitation mechanism in the cloud, and in any case provides an upper limit to the column abundance.

Optical Line Emission from IO

In early summer of 1972, we discovered an anomalous brightness in the spectrum of Io near the sodium D-lines. This effect is revealed to be time-varying emission by free sodium atoms on Io.

The electron resonance spectra of BrO, IO and SeF inJ=5/2 rotational levels

The electron resonance spectra of BrO, IO and SeF in the J = 5/2 rotational levels of their ground 2II states have been observed and analysed. Comparison of these results with those obtained in the J = 3/2 levels leads to values for corrections to the magnetic moment arising principally from third-order effects of the spin-orbit coupling.

Gas-Phase Electron Resonance Spectra of BrO and IO

The gas-phase electron resonance spectra of BrO and IO in their π23/2 levels are described. The analysis confirms that both radicals have π23/2 ground electronic states, and values of the fine-structure splitting A and rotational constant B0 are obtained. Nuclear hyperfine structure from 79Br and 81Br in BrO and 127I in IO is observed. Analysis yields values for the axial component of the magnetic hyperfine interaction, and also values for the electric quadrupole coupling constants.

Gas-phase electron resonance spectra of SF, SeF, SeO (3Σ and1Δ) and IO

The first page of this article is displayed as the abstract.

Saturn's Ring and the Satellites of Jupiter: Interpretations of Infrared Spectra

Infrared spectra of Saturn's ring correspond closely with the reflection spectrum of water ice. This result supports Kuiper's suggestion for the composition of the ring. The absence of the strong absorption at 8873 A in spectra of Io, Ganymede, and Callisto leads to a new upper limit for the abundance of methane in possible atmospheres of these satellites.

Electronic Spectrum of IO− in Solution

COMPOUNDS of iodine in the +1 oxidation state are unstable in aqueous solution, and for this reason their chemistry is still not clearly defined. Recording the absorption spectrum of IO− should be helpful for a systematic investigation of this group. Conflicting reports have been published on this subject1,2. Apart from the instability of IO−, the main difficulty arises from the overlap of its spectrum with that of other iodine compounds, in particular that of . High alkalinity and low I− concentration are desirable for suppressing the formation of and other +1 iodine compounds as HIO, I2OH− I2O = (ref. 1). Here we report the results of a spectrophotometric examination of iodine in highly concentrated alkali solutions.

ABSORPTION SPECTRA OF THE HALOGEN MONOXIDES

Absorption spectra of ClO, BrO, and IO have been observed during the flash photolysis of Cl2–O2, Br2–O2, and I2–O2 mixtures. Rotational and vibrational analyses of the ClO and BrO spectra have been carried out and appropriate molecular constants derived. The transitions are of the type 2Πi(case a)—2Πi (case a). Extensive predissociation has been observed in all three spectra. Theoretical and experimental evidence is presented to show that the excited states dissociate to X(2P3/2) + O(1D). From the observed or extrapolated convergence limits of the absorption spectra the dissociation energies of the ground states are shown to be D0″(ClO) = 63.31 ± 0.03 kcal./mole, D0″ (BrO) = 55.2 ± 0.6 kcal./mole, D0″ (IO) = 42 ± 5 kcal./mole. Mechanisms for the production of the halogen monoxides are discussed and evidence is presented for the participation of excited [Formula: see text] halogen atoms.