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Recent observations have suggested that there is water ice present on the surfaces of 24 Themis and 1 Ceres. We present upper limits on the H2O production rate on these bodies derived using a search for [O I]6300 Å emission. For Themis, the water production is less than 4.5 × 1027 mol s−1, while for Ceres our derived upper limit is 4.6 × 1028 mol s−1. The derived limits imply a very low fraction of...
Carbon dioxide is one of the most abundant ices present in comets and is therefore important for understanding cometary composition and activity. We present analysis of observations of CO2 and [OI] emission in three comets to measure the CO2 abundance and evaluate the possibility of employing observations of [OI] emission in comets as a proxy for CO2. We obtained NIR imaging sensitive to CO2 of comets...
We present analysis of high spectral resolution NIR spectra of CO and H 2 O in Comet C/2009 P1 (Garradd) taken during its 2011–2012 apparition with the CSHELL instrument on NASA’s Infrared Telescope Facility (IRTF). We also present analysis of observations of atomic oxygen in Comet Garradd obtained with the ARCES echelle spectrometer mounted on the ARC 3.5-m telescope at Apache Point Observatory...
We present analysis of high spectral resolution optical spectra of Comet 103P/Hartley taken during its Fall 2010 apparition. These spectra include transitions belonging to CN, C2, CH, NH2, and OI. We measure production rates and mixing ratios from these spectra. We find evidence for large changes in production rates (factors of a few) over the course of a nucleus rotation, in agreement with other...
We obtained high-resolution (λ/Δλ∼28,000) infrared spectra of Comet 103P/Hartley 2 on UT 2010 November 4.6 using the NIRSPEC spectrometer at the W.M. Keck Observatory. Here we present spectra of Hartley 2 between 2.832 and 3.639μm (3531–2748cm −1 ), representing the most complete high-resolution infrared survey of a Jupiter-family comet to date in this wavelength region. We have tabulated...
We present analysis of observations of the forbidden oxygen lines in Comet 103P/Hartley, the target of the Deep Impact Extended Investigation (DIXI), during its Fall 2010 apparition. We obtained the observations using the ARCES echelle spectrometer mounted on the Astrophysical Research Consortium (ARC) 3.5-m telescope at Apache Point Observatory. We detected the 5577, 6300, and 6364Å lines on all...
We conducted high-dispersion spectroscopic observations of Comet 103P/Hartley 2 in the near-infrared wavelength region using the Keck II telescope with NIRSPEC. We obtained observations on four dates, with the last observations performed during the EPOXI closest approach. For this work we focus on the observations performed on UT 2010 October 17 and 21, while observations carried out on UT 2010 September...
We present observations and analysis of the forbidden oxygen lines in Comets C/2006 W3 (Christensen) and C/2007 Q3 (Siding Spring) at heliocentric distances of 3.13 and 2.96AU, respectively. We obtained the observations using the ARCES echelle spectrometer, which is mounted on the Astrophysical Research Consortium 3.5-m telescope at Apache Point Observatory. We detected the 5577, 6300, and 6364Å atomic...
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