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arXiv · 1012.1137

Model for Cameron band emission in comets: A case for EPOXI mission target comet 103P/Hartley 2

Anil Bhardwaj·Susarla Raghuram
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Abstract

The CO2 production rate has been derived in comets using the Cameron band (a3Pi - X1Sigma) emission of CO molecule assuming that photodissociative excitation of CO2 is the main production mechanism of CO in a3Pi metastable state. We have devoloped a model for the production and loss of CO(a3Pi) which has been applied to comet 103P/Hartley 2: the target of EPOXI mission. Our model calculations show that photoelectron impact excitation of CO and dissociative excitation of CO2 can together contribute about 60-90% to the Cameron band emission. The modeled brightness of (0-0) Cameron band emission on comet Hartley 2 is consistent with Hubble Space Telescope observations for 3-5% CO2 (depending on model input solar flux) and 0.5% CO relative to water, where photoelectron impact contribution is about 50-75%. We suggest that estimation of CO2 abundances on comets using Cameron band emission may be reconsidered. We predict the height integrated column brightness of Cameron band of ~1300 R during EPOXI mission encounter period.

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Anil Bhardwaj, Susarla Raghuram. 2010-12-06. Model for Cameron band emission in comets: A case for EPOXI mission target comet 103P/Hartley 2. https://doi.org/10.1111/j.1745-3933.2010.00998.x

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