Detection of Atomic Chlorine in Io’s Atmosphere with HST/GHRS
نویسندگان
چکیده
We report the detection of atomic chlorine emissions in the atmosphere of Io using Hubble Space Telescope observations with the Goddard High Resolution Spectrograph (GHRS). The Cl I λ1349 dipole allowed and Cl I] λ1386 forbidden transition multiplets are detected at a signal to noise ratio (SNR) of 6 and 10, respectively, in a combined GHRS spectrum acquired from 1994 through 1996. Oxygen and sulfur emissions are simultaneously detected with the chlorine which allows for self-consistent abundance ratios of chlorine to these other atmospheric species. The disk averaged ratios are: Cl/O = 0.017 ± 0.008, Cl/S = 0.10 ± 0.05, and S/O = 0.18 ± 0.08. We also derive a geometric albedo of 1.0± 0.4 % for Io at 1335 Å assuming an SO2 atmospheric column density of 1×10 cm. Subject headings: planets and satellites: individual (Io)—ultraviolet: solar system
منابع مشابه
Alkali and Chlorine Photochemistry in a VolcanicallyDriven Atmosphere on Io
Observations of the Io plasma torus and neutral clouds indicate that the extended ionian atmosphere must contain sodium, potassium, and chlorine in atomic and/or molecular form. Models that consider sublimation of pure sulfur dioxide frost as the sole mechanism for generating an atmosphere on Io cannot explain the presence of alkali and halogen species in the atmosphere—active volcanoes or surf...
متن کاملChemistry of Sodium, Potassium, and Chlorine in Volcanic Gases on Io
We used thermochemical equilibrium calculations in the O–S– Na–K–Cl–H system to model the speciation of volcanic gases emitted from high-temperature (1000–2000 K) silicate magmas on Io. The effects of temperature, pressure, and bulk composition of the gases are explored. The bulk compositions are based on atomic ratios observed in Io’s plasma torus and extended atmosphere, and from chondritic a...
متن کاملThe Significance of the Sodium Detection in the Extrasolar Planet HD 209458 b Atmosphere
The Hubble Space Telescope (HST) detection of an extra-solar planet atmosphere in 2001 was a landmark step forward for the characterization of extrasolar planets. HST detected the trace element sodium, via the neutral atomic resonance doublet at 593 nm, in the tran-siting extrasolar giant planet HD 209458 b. In this paper I discuss the significance of this first ever extrasolar planet atmospher...
متن کاملMid-Infrared Detection of Large Longitudinal Asymmetries in Io’s SO2 Atmosphere
We have observed about 16 absorption lines of the ν2 SO2 vibrational band on Io, in disk-integrated 19 μm spectra taken with the TEXES high spectral resolution mid-infrared spectrograph at the NASA Infrared Telescope Facility in November 2001, December 2002, and January 2004. These are the first ground-based infrared observations of Io’s sunlit atmosphere, and provide a new window on the atmosp...
متن کاملAtomic and Molecular Data for Stellar Physics: Former Successes and Future Challenges
This review highlights current (and future!) hot topics in astrophysics where atomic or molecular input data are (or will be) essential, with special emphasis on topics relating to nucleosynthesis and cosmochemistry. We first discuss issues (like the abundances of oxygen and iron in the Sun, and that of lithium in post-AGB stars) where the use of poor-quality atomic or molecular data have led t...
متن کامل