Radio Monitoring of 9P/Tempel 1 Outgassing and Gas Released by the Impact

As part of the international observing campaign in support of the NASA Deep Impact mission to comet 9P/Tempel 1, we conducted a monitoring of its outgassing at radio wavelengths. OH observations conducted at the Nancay radio telescope provided a 4-month monitoring of the comet from March to July, followed by the observation of H2O with the Odin satellite from June to August 2005. The peak of outgassing was found to be around 1028 molec. s-1 between May and July. Observations of HCN conducted with the IRAM 30 m radio telescope in May 2005 showed a variation of the production rate with a period of 1.73±0.10 days, consistent with the rotation period of the nucleus.