First results of ISO-SWS observations of Jupiter.
Beintema, D. A.; Lellouch, E.; Encrenaz, T.; de Graauw, T.; Morris, P.; Feuchtgruber, H.; Drossart, P.; Griffin, M.; Salama, A.; Roelfsema, P. R.; Vandenbussche, B.; Heras, A.; Naylor, D. A.; Roos-Serote, M.; Leech, K.; Valentijn, E. A.; Bezard, B.; Kessler, M.; Davis, G. R.; Schaeidt, S.
Abstract
The spectrum of Jupiter has been recorded between 2.75 and 14.5μm with the grating mode of the Short-Wavelength Spectrometer (SWS) of ISO. The resolving power is 1500. The main preliminary results of this observation are (1) at 3μm, the first spectroscopic signature, probably associated with NH_3_ ice, of the Jovian cloud at 0.5 bar and (2) the first detection of a thermal emission at the center of the CH_4_-ν_3_ band at 3.3μm, showing evidence for a high temperature in the upper jovian stratosphere (T=800K at P=0.16 microbar). In addition, the R(2) HD line has been detected for the first time in Jupiter, using the Fabry-Perot (FP) mode of the SWS, with a resolving power of 31000. A preliminary analysis of the HD line indicates a D/H ratio of about 2.2x10^-5^.