The big lobe of 67P/Churyumov-Gerasimenko comet: morphological and spectrophotometric evidences of layering as from OSIRIS data

DOI: 
10.1093/mnras/sty1656
Publication date: 
01/06/2018
Main author: 
Ferrari, Sabrina
IAA authors: 
Gutiérrez, P. J.;Lara, L. M.;López-Moreno, J. J.
Authors: 
Ferrari, Sabrina;Penasa, L.;La Forgia, F.;Massironi, M.;Naletto, G.;Lazzarin, M.;Fornasier, S.;Hasselmann, P. H.;Lucchetti, A.;Pajola, M.;Ferri, F.;Cambianica, P.;Oklay, N.;Tubiana, C.;Sierks, H.;Lamy, P. L.;Rodrigo, R.;Koschny, D.;Davidsson, B.;Barucci, M. A.;Bertaux, J. -L.;Bertini, I.;Bodewits, D.;Cremonese, G.;Da Deppo, V.;Debei, S.;De Cecco, M.;Deller, J.;Franceschi, M.;Frattin, E.;Fulle, M.;Groussin, O.;Gutiérrez, P. J.;Güttler, C.;Hviid, S. F.;Ip, W. -H.;Jorda, L.;Keller, H. U.;Knollenberg, J.;Kührt, E.;Küppers, M.;Lara, L. M.;López-Moreno, J. J.;Marzari, F.;Shi, X.;Simioni, E.;Thomas, N.;Vincent, J. -B.
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Pages: 
1555-1568
Abstract: 
Between 2014 and 2016, ESA's Rosetta OSIRIS cameras acquired multiple-filters images of the layered nucleus of comet 67P/Churyumov-Gerasimenko, ranging from ultraviolet to near-infrared wavelengths. No correlation between layers disposition and surface spectral variegation has been observed so far. This paper investigates possible spectral differences among decametre-thickness outcropping layers of the biggest lobe of the comet by means of OSIRIS image dataset. A two-classes Maximum Likelihood classification was applied on consolidated outcrops and relative deposits identified on post-perihelion multispectral images of the big lobe. We distinguished multispectral data on the basis of the structural elevation of the onion-shell Ellipsoidal Model of 67P. The spatial distribution of the two classes displays a clear dependence on the structural elevation, with the innermost class resulting over 50% brighter that the outermost one. Consolidated cometary materials located at different structural levels are characterized by different brightness and revealed due to the selective removal of large volumes. This variegation can be attributed to a different texture of the outcrop surface and/or to a different content of refractory materials.
Database: 
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2018MNRAS.479.1555F/abstract
ADS Bibcode: 
2018MNRAS.479.1555F
Keywords: 
methods: data analysis;techniques: image processing;comets: general;comets: individual: 67P/Churyumov;Gerasimenko