The following document lists the file abstract/BBEZARD_JUPSAT_1.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
We propose to use the SWS in the high-resolution F-P mode to
search for spectral signatures from diacetylene (C4H2) and benzene
(C6H6) on Jupiter and Saturn. These two undetected compounds are
expected to be produced from the photochemistry of methane in the
high atmosphere. Diacetylene is the first step in the formation of
polyacetylenes which may contribute to the stratospheric hazes.
Benzene is the simplest aromatic molecule and may be a pathway to
the formation of more complex aromatics which could contribute to
the brownish chromophores and to the formation of a photochemical
smog. Detecting these two molecules and measuring their concentration
profiles would provide a test for some chemical schemes proposed in
photochemical models, and help determining some important atmospheric
parameters.
We will search for thermal emission from the C6H6 band at
14.8 micron and the C4H2 band at 15.9 micron. These are by far the
most favorable rovibrational bands in the thermal IR. They occur
in a spectral region inaccessible from the ground, and ISO offers
the only opportunity in the near future to detect for the first time
these important compounds.
The gain in spectral resolution provided by the F-P mode
compared with the Grating mode of the SWS may be needed to detect
unambiguously the expected weak signatures superimposed on the strong
H2 continuum. The F-P resolution is also needed to separate the
C6H6 emission from a possible emission from HCP near 14.84 micron on
Saturn. F-P observations will furthermore allow the measurement of
the profiles of the Q-branches from C6H6 and C4H2, providing valuable
information on the vertical profiles of these species.
Synthetic calculations based on realistic abundances of these
two compounds show that these signatures should be easily detectable
by SWS in the F-P mode.