Thermal modelling of water activity on comet 67P/Churyumov-Gerasimenko with global dust mantle and plural dust-to-ice ratio

DOI: 
10.1093/mnras/stx1607
Publication date: 
01/07/2017
Main author: 
Hu, X.
IAA authors: 
Gutiérrez, P. J.;Lara, L. M.;López-Moreno, J. J.
Authors: 
Hu, X.;Shi, X.;Sierks, H.;Blum, J.;Oberst, J.;Fulle, M.;Kührt, E.;Güttler, C.;Gundlach, B.;Keller, H. U.;Mottola, S.;Pajola, M.;Barbieri, C.;Lamy, P. L.;Rodrigo, R.;Koschny, D.;Rickman, H.;Agarwal, J.;A'Hearn, M. F.;Barucci, M. A.;Bertaux, J. -L.;Bertini, I.;Boudreault, S.;Büttner, I.;Cremonese, G.;Da Deppo, V.;Davidsson, B.;Debei, S.;De Cecco, M.;Deller, J.;Fornasier, S.;Groussin, O.;Gutiérrez, P. J.;Gutiérrez-Marqués, P.;Hall, I.;Hofmann, M.;Hviid, S. F.;Ip, W. -H.;Jorda, L.;Knollenberg, J.;Kovacs, G.;Kramm, J. R.;Küppers, M.;Lara, L. M.;Lazzarin, M.;López-Moreno, J. J.;Marzari, F.;Naletto, G.;Oklay, N.;Richards, M. L.;Ripken, J.;Thomas, N.;Tubiana, C.;Vincent, J. -B.
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Volume: 
469
Pages: 
S295-S311
Abstract: 

We perform a thermo-physical analysis on water activity of comet 67P/Churyumov-Gerasimenko (67P). The sublimation of water is assumed to occur from beneath a global, desiccated dust mantle over the irregular-shaped nucleus. The concept of two thermal models, the recipe of model formulation and the strategy of application to comet 67P are described. For an accurate and efficient evaluation of energy input by insolation and self-heating over the nucleus, a Landscape data base is devised based on polyhedral shape models of the nucleus. We apply the thermal models to investigate the impact of certain parameters of nucleus properties on water production. It is found that the measured water production of 67P can be overall attributed to sublimation of water ice with a mass abundance of a few to 10 per cent beneath a uniform dust mantle of several millimetres to one centimetre in thickness. Insofar as 67P is concerned, we argue against the necessity to invoke assumptions on localized water activity, or on the distinction of active/dormant surface areas.

Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85037056119&doi=10.1093%2fmnras%2fstx1607&partnerID=40&md5=8744a8964f78bbf2256fa21895f4ea7f
ADS Bibcode: 
2017MNRAS.469S.295H
Keywords: 
solid state: refractory;solid state: volatile;methods: numerical;comets: general;comets: individual (67P/Churyumov-Gerasimenko)