Modelling of the outburst on 2015 July 29 observed with OSIRIS cameras in the Southern hemisphere of comet 67P/Churyumov─Gerasimenko

DOI: 
10.1093/mnras/stx1441
Publication date: 
01/07/2017
Main author: 
Gicquel, A.
IAA authors: 
Gutiérrez, P. J.;Lara, L. M.;Moreno, J. J. Lopez;Moreno, F.
Authors: 
Gicquel, A.;Rose, M.;Vincent, J. -B.;Davidsson, B.;Bodewits, D.;A'Hearn, M. F.;Agarwal, J.;Fougere, N.;Sierks, H.;Bertini, I.;Lin, Z. -Y.;Barbieri, C.;Lamy, P. L.;Rodrigo, R.;Koschny, D.;Rickman, H.;Keller, H. U.;Barucci, M. A.;Bertaux, J. -L.;Besse, S.;Boudreault, S.;Cremonese, G.;Da Deppo, V.;Debei, S.;Deller, J.;De Cecco, M.;Frattin, E.;El-Maarry, M. R.;Fornasier, S.;Fulle, M.;Groussin, O.;Gutiérrez, P. J.;Gutiérrez-Marquez, P.;Güttler, C.;Höfner, S.;Hofmann, M.;Hu, X.;Hviid, S. F.;Ip, W. -H.;Jorda, L.;Knollenberg, J.;Kovacs, G.;Kramm, J. -R.;Kührt, E.;Küppers, M.;Lara, L. M.;Lazzarin, M.;Moreno, J. J. Lopez;Lowry, S.;Marzari, F.;Masoumzadeh, N.;Massironi, M.;Moreno, F.;Mottola, S.;Naletto, G.;Oklay, N.;Pajola, M.;Preusker, F.;Scholten, F.;Shi, X.;Thomas, N.;Toth, I.;Tubiana, C.
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Volume: 
469
Pages: 
S178-S185
Abstract: 

Images of the nucleus and the coma (gas and dust) of comet 67P/Churyumov- Gerasimenko have been acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) cameras since 2014 March using both the wide-angle camera and the narrow-angle camera (NAC). We use images from the NAC camera to study a bright outburst observed in the Southern hemisphere on 2015 July 29. The high spatial resolution of the NAC is needed to localize the source point of the outburst on the surface of the nucleus. The heliocentric distance is 1.25 au and the spacecraft-comet distance is 186 km. Aiming to better understand the physics that led to the outgassing, we used the Direct Simulation Monte Carlo method to study the gas flow close to the nucleus and the dust trajectories. The goal is to understand the mechanisms producing the outburst. We reproduce the opening angle of the outburst in the model and constrain the outgassing ratio between the outburst source and the local region. The outburst is in fact a combination of both gas and dust, in which the active surface is approximately 10 times more active than the average rate found in the surrounding areas. We need a number of dust particles 7.83 × 10<SUP>11</SUP> to 6.90 × 10<SUP>15</SUP> (radius 1.97-185 μm), which correspond to a mass of dust (220-21) × 10<SUP>3</SUP> kg.

Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85037037054&doi=10.1093%2fmnras%2fstx1441&partnerID=40&md5=374f1d1e60b5ec5f2a361c47b55ebdb8
ADS Bibcode: 
2017MNRAS.469S.178G
Keywords: 
methods: data analysis;methods: numerical;methods: observational;comets: individual: 67P/Churyumov;Gerasimenko;Astrophysics - Earth and Planetary Astrophysics