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Radio observations of comet 9P/Tempel 1 with the Australia Telescope facilities during the Deep Impact encounter

P. A. Jones·J. M. Sarkissian·M. G. Burton·M. A. Voronkov·M. D. Filipovic
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Abstract

We present radio observations of comet 9P/Tempel 1 associated with the Deep Impact spacecraft collision of 2005 July 4. Weak 18-cm OH emission was detected with the Parkes 64-m telescope, in data averaged over July 4 to 6, at a level of 12 +/- 3 mJy km/s, corresponding to OH production rate 2.8 x 10^{28} molecules/second (Despois et al. inversion model, or 1.0 x 10^{28} /s for the Schleicher & A'Hearn model). We did not detect the HCN 1-0 line with the Mopra 22-m telescope over the period July 2 to 6. The 3 sigma limit of 0.06 K km/s for HCN on July 4 after the impact gives the limit to the HCN production rate of < 1.8 x 10^{25} /s. We did not detect the HCN 1-0 line, 6.7 GHz CH_3OH line or 3.4-mm continuum with the Australia Telescope Compact Array (ATCA) on July 4, giving further limits on any small-scale structure due to an outburst. The 3 sigma limit on HCN emission of 2.5 K km/s from the ATCA around impact corresponds to limit < 4 x 10^{29} HCN molecules released by the impact.

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P. A. Jones, J. M. Sarkissian, M. G. Burton, M. A. Voronkov, M. D. Filipovic. 2006-04-24. Radio observations of comet 9P/Tempel 1 with the Australia Telescope facilities during the Deep Impact encounter. https://doi.org/10.1111/j.1365-2966.2006.10460.x

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