ASTE Observation of Jupiter's Stratospheric Composition: Detection of Carbon Monosulfide ($J$=7--6) in 19 Years After the Cometary Impact

TL;DR

This study detects and analyzes carbon monosulfide in Jupiter's stratosphere 19 years after a comet impact, revealing its decreasing abundance and vertical distribution, which informs sulfur chemistry models.

Contribution

First detection of CS J=7--6 in Jupiter's stratosphere 19 years post-impact, providing new data on its abundance and vertical distribution.

Findings

CS abundance decreased by 90% since 1998

CS is present above 0.2 mbar pressure level

Discrepancy in vertical distribution suggests chemical loss

Abstract

In Jupiter's stratosphere, gaseous carbon monosulfide (CS) was first discovered in 1994 by millimeter and ultraviolet observations as a product induced by the collision of comet Shoemaker-Levy 9 (SL9). {To constrain sulfur chemistry, in 2013, 19 years after the SL9 event, we observed Jupiter's stratospheric CS $J$=7 -- 6 rotational transition at 0.8 mm wavelength by using the Atacama Submillimeter Telescope Experiment (ASTE) 10-m single dish telescope. The CS molecular line was successfully detected with 120 mK intensity in the antenna temperature scale. The obtained CS total mass shows $\sim$90$\%$ decrease relative to that observed in 1998. From the line shape analysis, CS is suggested to be present above the 0.2$^{+0.4}_{-0.15}$ mbar pressure level, which is comparable to that of determined in 1998 which was provided by SL9 along with CS, was observed up to the 2.0 mbar pressure region. The discrepancy of CS vertical distribution with \ce{H2O} and the decrease in its total mass may be attributed to the chemical loss of CS in Jupiter's stratosphere lower than the 0.2 mbar altitude region.