Sunset jets observed on comet 67P/Churyumov-Gerasimenko sustained by subsurface thermal lag

Please use this identifier to cite or link to this item: https://ir.lib.ncu.edu.tw/handle/987654321/101854

Title:	Sunset jets observed on comet 67P/Churyumov-Gerasimenko sustained by subsurface thermal lag
Authors:	葉永烜;Shi, X.;Hu, X.;Sierks, H.;Güttler, C.;A’Hearn, M.;Blum, J.;El-Maarry, M. R.;Kührt, E.;Mottola, S.;Pajola, M.;Oklay, N.;Fornasier, S.;Tubiana, C.;Keller, H. U.;Vincent, J.-B.;Bodewits, D.;Höfner, S.;Lin, Z.-Y.;Gicquel, A.;Hofmann, M.;Barbieri, C.;Lamy, P. L.;Rodrigo, R.;Koschny, D.;Rickman, H.;Barucci, M. A.;Bertaux, J.-L.;Bertini, I.;Cremonese, G.;Da Deppo, V.;Davidsson, B.;Debei, S.;De Cecco, M.;Fulle, M.;Groussin, O.;Gutiérrez, P. J.;Hviid, S. F.;Ip, W.-H.;Jorda, L.;Knollenberg, J.;Kovacs, G.;Kramm, J.-R.;Küppers, M.;Lara, L. M.;Lazzarin, M.;Lopez-Moreno, J. J.;Marzari, F.;Naletto, G.;Thomas, N.
Contributors:	理學院天文研究所
Keywords:	Astrophysics;Comet nuclei;Comets;comets: individual: 67P/Churyumov-Gerasimenko;Dust;Earth and Planetary Astrophysics;Illumination;Instrumentation and Methods for Astrophysic;Jets;Meters;Sciences of the Universe;Solar and Stellar Astrophysics;Sublimation;Sunset
Date:	2016-02-01
Issue Date:	2026-04-21 14:48:16 (UTC+8)
Publisher:	EDP Sciences
Abstract:	摘要： We present observations of sunset jets on comet 67P/Churyumov-Gerasimenko by Rosetta/OSIRIS camera. In late April 2015, when the comet was at a heliocentric distance of ~1.8 AU, clusters of dust jets that originated in the Ma’at region on the comet’s small lobe were identified from multipleimages and were apparently sustained for about an hour beyond local sunset. Emanating from the shadowed nucleus, these jets became visible by solar illumination at their apparent sources up to only a few tens of meters above the nucleus surface. We investigate the plausibility of these jets as having been triggered by water ice sublimation and sustained by thermal lag in the subsurface beyond sunset. A general thermo-physical model was parameterized such that the thermal lag in the subsurface is consistent with the elapsed time of observation after sunset. It is found that the sublimation of water ice from a depth of 6 mm and with a low thermal inertia of 50 W m-2 K-1 s1/2 could explain the spatial pattern and evolution of the apparent sources, particularly their disappearance due to the eventual cooling of the subsurface. Our analysis suggests that these sunset jets were essentially day-side dust activities that continued after sunset. Specific observational conditions for the sunset jets constrain their possible sources to mostly within the less abrupt, dusty terrains. The uneven distribution of these jets is possibly related to subsurface inhomogeneities in the dusty area. 出版者： EDP Sciences 出版日期： 2016-02-01 出處： Astronomy and astrophysics (Berlin), 2016-02, Vol.586, p.A7 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: 10.1051/0004-6361/201527123
Appears in Collections:	[Graduate Institute of Astronomy] journal & Dissertation

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