CO in the atmospheres of Saturn and Uranus. Observations at millimeter and submillimeter wavelengths.

An external supply of oxygenated compounds exists in outer planets. Carbon monoxide has been detected in each giant planet. The source of CO has been proved to be dual (internal and external) in Jupiter and Neptune, but this is still unclear in the case of Saturn and Uranus. Therefore, constraining the amount of CO in the troposphere and stratosphere of these planets would help solve this problem. We performed observations of Saturn and Uranus at millimeter and submillimeter wavelengths in the CO (1-0), (2-1) and (3-2) lines. Observations were carried out with the IRAM 30-m telescope (Pico Veletta, Spain) in September 2006 and with the JCMT 15-m telescope (Hawaii, USA) in January 2008. We have recorded broad multi-band spectra of each planet. The results of these observations are presented and discussed.