Inventory of the volatiles on comet 67P/Churyumov-Gerasimenko from Rosetta/ROSINA
Inventory of the volatiles on comet 67P/Churyumov-Gerasimenko from Rosetta/ROSINA
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DOI：
10.1051/0004-6361/201526450
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发表时间：
2015-11-01
影响因子：
6.5
通讯作者：
Tzou, Chia-Yu
中科院分区：
文献类型：
--
作者：
Le Roy, Lena;Altwegg, Kathrin;Tzou, Chia-Yu
语境。欧空局罗塞塔号航天器 (S/C) 正在追踪附近的 67P/Churyumov-Gerasimenko 彗星。这种长时间的接触使得研究挥发性彗发成分的演变成为可能。我们的工作旨在比较大日心距离处 67P/Churyumov-Gerasimenko 彗发的多样性，以研究该彗星在绕太阳运行期间的演化，并尝试将其与其他彗星进行分类。方法。我们使用欧空局罗塞塔任务中 ROSINA 实验的双聚焦质谱仪 (DFMS) 来确定主要和次要挥发性物质的相对丰度。这项研究仅限于以前在其他地方检测到的物种。结果。我们使用 ROSINA DFMS 检测到目前已知存在于彗发中的几乎所有物种。由于 DFMS 在本地测量了成分，我们无法得出全球丰度，但我们将夏季和冬季半球的测量结果与其他彗星的已知丰度进行比较。夏半球和冬半球的相对丰度之间存在很大差异，这表明彗星表面可能存在演化。这颗彗星似乎富含二氧化碳和乙烷。乙二醇等重含氧化合物的含量不足 3 个天文单位，可能是由于其升华温度高，但尽管如此，它们的存在证明柯伊伯带彗星也含有复杂的有机分子。
Context. The ESA Rosetta spacecraft (S/C) is tracking comet 67P/Churyumov-Gerasimenko in close vicinity. This prolonged encounter enables studying the evolution of the volatile coma composition.Aims. Our work aims at comparing the diversity of the coma of 67P/Churyumov-Gerasimenko at large heliocentric distance to study the evolution of the comet during its passage around the Sun and at trying to classify it relative to other comets. Methods. We used the Double Focussing Mass Spectrometer (DFMS) of the ROSINA experiment on ESA's Rosetta mission to determine relative abundances of major and minor volatile species. This study is restricted to species that have previously been detected elsewhere.Results. We detect almost all species currently known to be present in cometary coma with ROSINA DFMS. As DFMS measured the composition locally, we cannot derive a global abundance, but we compare measurements from the summer and the winter hemisphere with known abundances from other comets. Differences between relative abundances between summer and winter hemispheres are large, which points to a possible evolution of the cometary surface. This comet appears to be very rich in CO2 and ethane. Heavy oxygenated compounds such as ethylene glycol are underabundant at 3 AU, probably due to their high sublimation temperatures, but nevertheless, their presence proves that Kuiper belt comets also contain complex organic molecules.