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| Dynamical properties and acceleration of hierarchical dust in the vicinity of comet 67P/Churyumov-Gerasimenko | |
| Skorov, Yu.1,2; Reshetnyk, V.3,4; Rezac, L.2; Zhao, Y.5; Marschall, R.6; Blum, J.1; Hartogh, P.2 | |
| 2018-07-01 | |
| Source Publication | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
 |
| ISSN | 0035-8711 |
| Volume | 477Issue:4Pages:4896-4907 |
| Corresponding Author | Skorov, Yu.(skorov@gmail.com) ; Reshetnyk, V.(reshetnyk@gmail.com) |
| Abstract | A significant fraction of cometary dust grains leaving the nucleus surface are extremely porous and fluffy particles as revealed by recent observation from the Rosetta mission. In this paper our aim is to investigate the dynamics of such grains when subjected to a gas flow, representing the cometary outgassing. We perform numerical experiments to quantify how the internal porous texture is reflected in quantities such as effective cross-section, gas drag coefficient, and light scattering efficiency. We also derive particle speeds for the different types of aggregates as a function of radial distance and compare them to the observations by the GIADA instrument. Using our original method for constructing hierarchical aggregates we increase the level of aggregation to reach particle sizes up to few millimeters, consistent with the observations. In addition, a non-constant gas velocity is now considered in the framework of free molecular as well as fully collisional flow models, and radiation pressure calculations use the effective medium theory appropriate for such particles. These improvements lead us to conclude that dynamical models should account for accelerating gas flow, which leads to a smaller terminal speed of fluffy dust grains. Secondly, solar radiation pressure calculated based on the Mie theory approximation can lead to orders of magnitude error for the very porous particles, instead the effective medium theory should be used. Finally, although numerical simulations can reproduce the GIADA measurements of dust speeds, we cannot conclude that there exists a preferred model of porous particles build as a ballistic cluster aggregate. |
| Keyword | methods: numerical comets: general comets: individual: 67P/Churyumov-Gerasimenko |
| DOI | 10.1093/mnras/sty1014 |
| WOS Keyword | OPTICAL-PROPERTIES ; PARTICLES ; GRAINS ; COAGULATION ; FORCES |
| Indexed By | SCI |
| Language | 英语 |
| WOS Research Area | Astronomy & Astrophysics |
| WOS Subject | Astronomy & Astrophysics |
| WOS ID | WOS:000435630100047 |
| Publisher | OXFORD UNIV PRESS |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://libir.pmo.ac.cn/handle/332002/21846 |
| Collection | 中国科学院紫金山天文台 |
| Corresponding Author | Skorov, Yu.; Reshetnyk, V. |
| Affiliation | 1.Tech Univ Carolo Wilhelmina Braunschweig, Inst Geophys & Extraterr Phys, Mendelssohnstr 3, D-38106 Braunschweig, Germany 2.Max Planck Inst Sonnensyst Forsch, Justus Von Liebig Weg 3, D-37077 Gottingen, Germany 3.Taras Shevchenko Natl Univ Kyiv, Glushkova Ave 2, UA-01601 Kiev, Ukraine 4.Natl Acad Sci Ukraine, Main Astron Observ, Akad Zabolotnoho Str 27, UA-03680 Kiev, Ukraine 5.Chinese Acad Sci, Purple Mt Observ, Key Lab Planetary Sci, Nanjing, Jiangsu, Peoples R China 6.Int Space Sci Inst, Hallerstr 6, CH-3012 Bern, Switzerland |
| Recommended Citation GB/T 7714 | Skorov, Yu.,Reshetnyk, V.,Rezac, L.,et al. Dynamical properties and acceleration of hierarchical dust in the vicinity of comet 67P/Churyumov-Gerasimenko[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2018,477(4):4896-4907. |
| APA | Skorov, Yu..,Reshetnyk, V..,Rezac, L..,Zhao, Y..,Marschall, R..,...&Hartogh, P..(2018).Dynamical properties and acceleration of hierarchical dust in the vicinity of comet 67P/Churyumov-Gerasimenko.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,477(4),4896-4907. |
| MLA | Skorov, Yu.,et al."Dynamical properties and acceleration of hierarchical dust in the vicinity of comet 67P/Churyumov-Gerasimenko".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 477.4(2018):4896-4907. |
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