MIRO observations of subsurface temperatures of the nucleus of 67P/Churyumov-Gerasimenko

Please use this identifier to cite or link to this item: https://ir.lib.ncu.edu.tw/handle/987654321/101680

Title:	MIRO observations of subsurface temperatures of the nucleus of 67P/Churyumov-Gerasimenko
Authors:	葉永烜;Schloerb, F. Peter;Keihm, Stephen;von Allmen, Paul;Choukroun, Mathieu;Lellouch, Emmanuel;Leyrat, Cedric;Beaudin, Gerard;Biver, Nicolas;Bockelée-Morvan, Dominique;Crovisier, Jacques;Encrenaz, Pierre;Gaskell, Robert;Gulkis, Samuel;Hartogh, Paul;Hofstadter, Mark;Ip, Wing-Huen;Janssen, Michael;Jarchow, Christopher;Jorda, Laurent;Keller, Horst Uwe;Lee, Seungwon;Rezac, Ladislav;Sierks, Holger
Contributors:	理學院天文研究所
Keywords:	Astronomy;Astrophysics;Brightness temperature;comets: general;comets: individual: 67P/Churyumov-Gerasimenko;Microwaves;Nuclei;Physical properties;Physics;radio continuum: planetary systems;Sciences of the Universe;Sublimation;Thermal emission;Wavelengths
Date:	2015-11-01
Issue Date:	2026-04-21 14:40:42 (UTC+8)
Publisher:	EDP Sciences
Abstract:	摘要： Observations of the nucleus of 67P/Churyumov-Gerasimenko in the millimeter-wave continuum have been obtained by the Microwave Instrument for the Rosetta Orbiter (MIRO). We present data obtained at wavelengths of 0.5 mm and 1.6 mm during September 2014 when the nucleus was at heliocentric distances between 3.45 and 3.27 AU. The data are fit to simple models of the nucleus thermal emission in order to characterize the observed behavior and make quantitative estimates of important physical parameters, including thermal inertia and absorption properties at the MIRO wavelengths. MIRO brightness temperatures on the irregular surface of 67P are strongly affected by the local solar illumination conditions, and there is a strong latitudinal dependence of the mean brightness temperature as a result of the seasonal orientation of the comet’s rotation axis with respect to the Sun. The MIRO emission exhibits strong diurnal variations, which indicate that it arises from within the thermally varying layer in the upper centimeters of the surface. The data are quantitatively consistent with very low thermal inertia values, between 10–30 J K-1 m-2 s-1/2, with the 0.5 mm emission arising from 1 cm beneath the surface and the 1.6 mm emission from a depth of 4 cm. Although the data are generally consistent with simple, homogeneous models, it is difficult to match all of its features, suggesting that there may be some vertical structure within the upper few centimeters of the surface. The MIRO brightness temperatures at high northern latitudes are consistent with sublimation of ice playing an important role in setting the temperatures of these regions where, based on observations of gas and dust production, ice is known to be sublimating. 出版者： EDP Sciences 出版日期： 2015-11-01 出處： Astronomy & Astrophysics, 2015-11, Vol.583, p.A29- 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: 10.1051/0004-6361/201526152
Appears in Collections:	[Graduate Institute of Astronomy] journal & Dissertation

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