Variegation of comet 67P/Churyumov-Gerasimenko in regions showing activity

Please use this identifier to cite or link to this item: https://ir.lib.ncu.edu.tw/handle/987654321/101857

Title:	Variegation of comet 67P/Churyumov-Gerasimenko in regions showing activity
Authors:	葉永烜;Oklay, N.;Vincent, J.-B.;Fornasier, S.;Pajola, M.;Besse, S.;Davidsson, B. J. R.;Lara, L. M.;Mottola, S.;Naletto, G.;Sierks, H.;Barucci, A. M.;Scholten, F.;Preusker, F.;Pommerol, A.;Masoumzadeh, N.;Lazzarin, M.;Barbieri, C.;Lamy, P. L.;Rodrigo, R.;Koschny, D.;Rickman, H.;A’Hearn, M. F.;Bertaux, J.-L.;Bertini, I.;Bodewits, D.;Cremonese, G.;Da Deppo, V.;Debei, S.;De Cecco, M.;Fulle, M.;Groussin, O.;Gutiérrez, P. J.;Güttler, C.;Hall, I.;Hofmann, M.;Hviid, S. F.;Ip, W.-H.;Jorda, L.;Keller, H. U.;Knollenberg, J.;Kovacs, G.;Kramm, J.-R.;Kührt, E.;Küppers, M.;Lin, Z.-Y.;Lopez Moreno, J. J.;Marzari, F.;Moreno, F.;Shi, X.;Thomas, N.;Toth, I.;Tubiana, C.
Contributors:	理學院天文研究所
Keywords:	Absorption spectra;Astrophysics;Cameras;Comets;comets: individual: 67P/Churyumov-Gerasimenko;Earth and Planetary Astrophysics;methods: data analysis;Reflectance;Reflectivity;Sciences of the Universe;Silicates;Solar and Stellar Astrophysics;Spectra;Surface chemistry;techniques: image processing;techniques: imaging spectroscopy
Date:	2016-02-01
Issue Date:	2026-04-21 14:48:32 (UTC+8)
Publisher:	EDP Sciences
Abstract:	摘要： Aims.We carried out an investigation of the surface variegation of comet 67P/Churyumov-Gerasimenko, the detection of regions showing activity, the determination of active and inactive surface regions of the comet with spectral methods, and the detection of fallback material. Methods. We analyzed multispectral data generated with Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) narrow angle camera (NAC) observations via spectral techniques, reflectance ratios, and spectral slopes in order to study active regions. We applied clustering analysis to the results of the reflectance ratios, and introduced the new technique of activity thresholds to detect areas potentially enriched in volatiles. Results. Local color inhomogeneities are detected over the investigated surface regions. Active regions, such as Hapi, the active pits of Seth and Ma’at, the clustered and isolated bright features in Imhotep, the alcoves in Seth and Ma’at, and the large alcove in Anuket, have bluer spectra than the overall surface. The spectra generated with OSIRIS NAC observations are dominated by cometary emissions of around 700 nm to 750 nm as a result of the coma between the comet’s surface and the camera. One of the two isolated bright features in the Imhotep region displays an absorption band of around 700 nm, which probably indicates the existence of hydrated silicates. An absorption band with a center between 800–900 nm is tentatively observed in some regions of the nucleus surface. This absorption band can be explained by the crystal field absorption of Fe2+, which is a common spectral feature seen in silicates. 出版者： EDP Sciences 出版日期： 2016-02-01 出處： Astronomy and astrophysics (Berlin), 2016-02, Vol.586, p.A80 資源來源： EDP Sciences 版權： licence_http://creativecommons.org/publicdomain/zero 識別號： ISSN: 0004-6361 識別號： ISSN: 1432-0746 識別號： EISSN: 1432-0746 識別號： DOI: 10.1051/0004-6361/201527369
Appears in Collections:	[Graduate Institute of Astronomy] journal & Dissertation

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	19	View/Open

社群 sharing

Loading...