{"title":"不同日心距离下的 67P/C-G 等离子体成分建模","authors":"","doi":"10.1016/j.icarus.2024.116253","DOIUrl":null,"url":null,"abstract":"<div><p>The <em>Rosetta</em> spacecraft accompanied the comet 67P/C-G for nearly 2 years, collecting valuable data on the neutral and ion composition of the coma. The Rosetta Plasma Consortium (RPC) provided continuous measurements of the in situ plasma density while ROSINA-COPS monitored the neutral composition. In this work, we aim to estimate the composition of the cometary ionosphere at different heliocentric distances of the comet. Läuter et al. (2020) derived the temporal evolution of the volatile sublimation rates for 50 separated time intervals on the orbit of 67P/C-G using the COPS and DFMS data. We use these sublimation rates as inputs in a multifluid chemical-hydrodynamical model for 36 of the time intervals for heliocentric distances <span><math><mrow><mo><</mo><mn>3</mn></mrow></math></span> au. We compare the total ion densities obtained from our models with the local plasma density measured by the RPC instruments. We find that at the location of the spacecraft, our modeled ion densities match with the in situ measured plasma density within factors of <span><math><mrow><mn>1</mn><mo>−</mo><mn>3</mn></mrow></math></span> for many of the time intervals. We obtain the cometocentric distance variation of the ions H<sub>2</sub>O<sup>+</sup> and H<sub>3</sub>O<sup>+</sup> and the ion groups created respectively by the ionization and protonation of neutral species. We see that H<sub>3</sub>O<sup>+</sup> is dominant at the spacecraft location for nearly all the time intervals while ions created due to protonation are dominant at low cometocentric distances for the intervals near perihelion. We also discuss our ion densities in the context of their detection by DFMS.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Modeling the plasma composition of 67P/C-G at different heliocentric distances\",\"authors\":\"\",\"doi\":\"10.1016/j.icarus.2024.116253\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The <em>Rosetta</em> spacecraft accompanied the comet 67P/C-G for nearly 2 years, collecting valuable data on the neutral and ion composition of the coma. The Rosetta Plasma Consortium (RPC) provided continuous measurements of the in situ plasma density while ROSINA-COPS monitored the neutral composition. In this work, we aim to estimate the composition of the cometary ionosphere at different heliocentric distances of the comet. Läuter et al. (2020) derived the temporal evolution of the volatile sublimation rates for 50 separated time intervals on the orbit of 67P/C-G using the COPS and DFMS data. We use these sublimation rates as inputs in a multifluid chemical-hydrodynamical model for 36 of the time intervals for heliocentric distances <span><math><mrow><mo><</mo><mn>3</mn></mrow></math></span> au. We compare the total ion densities obtained from our models with the local plasma density measured by the RPC instruments. We find that at the location of the spacecraft, our modeled ion densities match with the in situ measured plasma density within factors of <span><math><mrow><mn>1</mn><mo>−</mo><mn>3</mn></mrow></math></span> for many of the time intervals. We obtain the cometocentric distance variation of the ions H<sub>2</sub>O<sup>+</sup> and H<sub>3</sub>O<sup>+</sup> and the ion groups created respectively by the ionization and protonation of neutral species. We see that H<sub>3</sub>O<sup>+</sup> is dominant at the spacecraft location for nearly all the time intervals while ions created due to protonation are dominant at low cometocentric distances for the intervals near perihelion. We also discuss our ion densities in the context of their detection by DFMS.</p></div>\",\"PeriodicalId\":13199,\"journal\":{\"name\":\"Icarus\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-08-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Icarus\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0019103524003130\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Icarus","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0019103524003130","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
摘要
该航天器伴随彗星 67P/C-G 近两年,收集了关于彗尾中性和离子成分的宝贵数据。罗塞塔等离子体联盟(RPC)对现场等离子体密度进行了连续测量,而 ROSINA-COPS 则对中性成分进行了监测。在这项工作中,我们旨在估算彗星不同日心距离上的彗星电离层成分。Läuter 等人(2020 年)利用 COPS 和 DFMS 数据得出了 67P/C-G 轨道上 50 个不同时间间隔的挥发性升华率的时间演变。我们将这些升华率作为日心距离 au 的多流体化学流体力学模型中 36 个时间间隔的输入。我们将从模型中得到的总离子密度与 RPC 仪器测得的局部等离子体密度进行了比较。我们发现,在航天器所在的位置,我们的模型离子密度与现场测量的等离子体密度在许多时间间隔内都相吻合。我们获得了离子 HO 和 HO 以及中性物质电离和质子化分别产生的离子群的彗心距离变化。我们发现,在几乎所有的时间间隔内,HO 在航天器位置都占主导地位,而在近日点附近的时间间隔内,质子化产生的离子在低彗心距离处占主导地位。我们还结合 DFMS 的探测结果讨论了我们的离子密度。
Modeling the plasma composition of 67P/C-G at different heliocentric distances
The Rosetta spacecraft accompanied the comet 67P/C-G for nearly 2 years, collecting valuable data on the neutral and ion composition of the coma. The Rosetta Plasma Consortium (RPC) provided continuous measurements of the in situ plasma density while ROSINA-COPS monitored the neutral composition. In this work, we aim to estimate the composition of the cometary ionosphere at different heliocentric distances of the comet. Läuter et al. (2020) derived the temporal evolution of the volatile sublimation rates for 50 separated time intervals on the orbit of 67P/C-G using the COPS and DFMS data. We use these sublimation rates as inputs in a multifluid chemical-hydrodynamical model for 36 of the time intervals for heliocentric distances au. We compare the total ion densities obtained from our models with the local plasma density measured by the RPC instruments. We find that at the location of the spacecraft, our modeled ion densities match with the in situ measured plasma density within factors of for many of the time intervals. We obtain the cometocentric distance variation of the ions H2O+ and H3O+ and the ion groups created respectively by the ionization and protonation of neutral species. We see that H3O+ is dominant at the spacecraft location for nearly all the time intervals while ions created due to protonation are dominant at low cometocentric distances for the intervals near perihelion. We also discuss our ion densities in the context of their detection by DFMS.
期刊介绍:
Icarus is devoted to the publication of original contributions in the field of Solar System studies. Manuscripts reporting the results of new research - observational, experimental, or theoretical - concerning the astronomy, geology, meteorology, physics, chemistry, biology, and other scientific aspects of our Solar System or extrasolar systems are welcome. The journal generally does not publish papers devoted exclusively to the Sun, the Earth, celestial mechanics, meteoritics, or astrophysics. Icarus does not publish papers that provide "improved" versions of Bode''s law, or other numerical relations, without a sound physical basis. Icarus does not publish meeting announcements or general notices. Reviews, historical papers, and manuscripts describing spacecraft instrumentation may be considered, but only with prior approval of the editor. An entire issue of the journal is occasionally devoted to a single subject, usually arising from a conference on the same topic. The language of publication is English. American or British usage is accepted, but not a mixture of these.