Rotational Variation of Daughter Species Production Rates in Comet 103P/Hartley: Implications for the Progeny of Daughter Species and the Degree of Chemical Heterogeneity
Rotational Variation of Daughter Species Production Rates in Comet 103P/Hartley: Implications for the Progeny of Daughter Species and the Degree of Chemical Heterogeneity
复制标题
彗星 103P/Hartley 子体物种生产率的旋转变化：对子体物种后代和化学异质性程度的影响
DOI：
10.1016/j.icarus.2013.11.029
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发表时间：
2014
期刊：
影响因子：
3.2
通讯作者：
N. Russo
中科院分区：
文献类型：
--
作者：
A. McKay;N. Chanover;M. DiSanti;J. Morgenthaler;A. Cochran;W. Harris;N. Russo
我们目前的高光谱分辨率的光学光谱的彗星103 P/哈特利在其2010年秋季出现的分析。这些光谱包括属于CN、C2、CH、NH 2和OI的跃迁。我们从这些光谱测量生产率和混合比。我们发现的生产率（几个因素）在一个核旋转的过程中，在协议与其他测量的大变化的证据。我们还测量了CN/H2O和C2/CN比的旋转相位的变化，这在以前没有任何彗星的报道。NH 2/H2O比率也可能随旋转相位而变化，但这种趋势不像CN/H2O那样明显。我们解释的混合比的变化是由于H2O和C2被释放主要从冰粒晕，而CN母分子直接来自核。有证据表明，CH/CN比率在近日点前比近日点后高。我们的结论是，所观察到的CN和NH 2的丰度是一致的HCN和NH3是这些物种的主要亲本分子。C_2和CH的丰度比候选母体分子（分别为C_2 H_2和CH_4）的丰度高，因此在~（103）P的彗发中，这些分子一定还有其它来源。碳质尘埃颗粒可以作为这种来源。
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 measurements. We also measure variability with rotational phase in the CN/H2O and C2/CN ratios, which has not been previously reported for any comet. There may also be variability in the NH2/H2O ratio with rotational phase, but this trend is not as clear as for CN/H2O. We interpret the changing mixing ratios as due to H2O and C2being released primarily from the icy grain halo, while the CN parent molecule comes directly from the nucleus. There is evidence that the CH/CN ratio is higher pre-perihelion than post-perihelion. We conclude that the observed CN and NH2abundances are consistent with HCN and NH3being the dominant parent molecules for these species. The C2and CH abundances are higher than those of candidate parent molecules (C2H2and CH4respectively), so there must be another source for these molecules in 103P’s coma. Carbonaceous dust grains could serve as this source.