Abundances and spatial distributions of H2O and CO2 at comet 9P/Tempel 1 during a natural outburst

作者：Moretto M J^*; Feaga L M; A'Hearn M F

来源：Icarus, 2017, 296: 28-38.

DOI：10.1016/j.icarus.2017.05.013

On approach to comet 9P/Tempel 1, Deep Impact observed about one dozen natural outbursts. One of the largest occurred on 2 July 2005 and was also captured by Deep Impact's infrared spectrometer, HRI-IR. HRI-IR operates between 1.05 and 4.86 mu m, allowing it to detect H2O (2.67 mu m) and CO2 (4.27 mu m) emission bands simultaneously. In the hours leading up to the outburst, both H2O and CO2 behaved quiescently, consistent with previously published studies. During the outburst, CO2 abundance increased by 40% while H2O abundance stayed constant. No additional species were detectable during the outburst. The distribution of CO2 during the outburst is correlated with that of the dust, observed at the same time in the visible. The abundance of CO2 returned to quiescent levels within 3.6 h of outburst onset. A slight enhancement in H2O was observed well after the outburst, though this does not appear to be correlated with the outburst. From this analysis, it is likely that CO2 was a driver of the 2 July 2005 outburst and that H2O was not.

• 出版日期2017-11-1