Solar wind charge exchange in cometary atmospheres III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko

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Solar wind charge exchange in cometary atmospheres III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko. / Wedlund, Cyril Simon; Behar, Etienne; Nilsson, Hans; Alho, Markku; Kallio, Esa; Gunell, Herbert; Bodewits, Dennis; Heritier, Kevin; Galand, Marina; Beth, Arnaud; Rubin, Martin; Altwegg, Kathrin; Volwerk, Martin; Gronoff, Guillaume; Hoekstra, Ronnie.

In: Astronomy & Astrophysics, Vol. 630, A37, 20.09.2019.

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Wedlund, CS, Behar, E, Nilsson, H, Alho, M, Kallio, E, Gunell, H, Bodewits, D, Heritier, K, Galand, M, Beth, A, Rubin, M, Altwegg, K, Volwerk, M, Gronoff, G & Hoekstra, R 2019, 'Solar wind charge exchange in cometary atmospheres III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko', Astronomy & Astrophysics, vol. 630, A37. https://doi.org/10.1051/0004-6361/201834881

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Wedlund, Cyril Simon ; Behar, Etienne ; Nilsson, Hans ; Alho, Markku ; Kallio, Esa ; Gunell, Herbert ; Bodewits, Dennis ; Heritier, Kevin ; Galand, Marina ; Beth, Arnaud ; Rubin, Martin ; Altwegg, Kathrin ; Volwerk, Martin ; Gronoff, Guillaume ; Hoekstra, Ronnie. / Solar wind charge exchange in cometary atmospheres III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko. In: Astronomy & Astrophysics. 2019 ; Vol. 630.

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@article{2fd480c625164235a6458c260d5272c8,
title = "Solar wind charge exchange in cometary atmospheres III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko",
abstract = "Solar wind charge-changing reactions are of paramount importance to thephysico-chemistry of the atmosphere of a comet. The ESA/Rosetta missionto comet 67P/Churyumov-Gerasimenko (67P) provides a unique opportunity to study charge-changing processes in situ. To understand the role of these reactions in the evolution of the solar wind plasma, and interpret the complex in-situ measurements made by Rosetta, numerical or analytical models are necessary. We use an extended analytical formalism describing solar wind charge-changing processes at comets along solarwind streamlines. The model is driven by solar wind ion measurements from the Rosetta Plasma Consortium-Ion Composition Analyzer (RPC-ICA) and neutral density observations from the Rosetta Spectrometer for Ion and Neutral Analysis-Comet Pressure Sensor (ROSINA-COPS), as well as charge-changing cross sections of hydrogen and helium particles in a water gas. A mission-wide overview of charge-changing efficiencies at comet 67P is presented. Electron capture cross sections dominate and favor the production of He and H energetic neutral atoms, with fluxes expected to rival those of H+ and He2+ ions. Neutral outgassing rates are retrieved from local RPC-ICA flux measurements, and match ROSINA's estimates very well. From the model, we find that solar wind charge exchange is unable to fully explain the magnitude of the sharp drop of solar wind ion fluxes observed by Rosetta for heliocentric distances below 2.5 AU. This is likely because the model does not take into account the relative ion dynamics and, to a lesser extent, ignore the formation of bow shock-like structures upstream of the nucleus. This work also shows that the ionization by solar EUV radiation and energetic electrons dominates the source of cometary ions, although solar wind contributions may be significant during isolated events.",
keywords = "Comets: General, comets: individual: 67P / Churyumov-Gerasimenko, instrumentation: detectors, solar wind, methods: analytical, solar wind: charge-exchange processes",
author = "Wedlund, {Cyril Simon} and Etienne Behar and Hans Nilsson and Markku Alho and Esa Kallio and Herbert Gunell and Dennis Bodewits and Kevin Heritier and Marina Galand and Arnaud Beth and Martin Rubin and Kathrin Altwegg and Martin Volwerk and Guillaume Gronoff and Ronnie Hoekstra",
year = "2019",
month = "9",
day = "20",
doi = "10.1051/0004-6361/201834881",
language = "English",
volume = "630",
journal = "Astronomy & Astrophysics",
issn = "0004-6361",

}

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TY - JOUR

T1 - Solar wind charge exchange in cometary atmospheres III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko

AU - Wedlund, Cyril Simon

AU - Behar, Etienne

AU - Nilsson, Hans

AU - Alho, Markku

AU - Kallio, Esa

AU - Gunell, Herbert

AU - Bodewits, Dennis

AU - Heritier, Kevin

AU - Galand, Marina

AU - Beth, Arnaud

AU - Rubin, Martin

AU - Altwegg, Kathrin

AU - Volwerk, Martin

AU - Gronoff, Guillaume

AU - Hoekstra, Ronnie

PY - 2019/9/20

Y1 - 2019/9/20

N2 - Solar wind charge-changing reactions are of paramount importance to thephysico-chemistry of the atmosphere of a comet. The ESA/Rosetta missionto comet 67P/Churyumov-Gerasimenko (67P) provides a unique opportunity to study charge-changing processes in situ. To understand the role of these reactions in the evolution of the solar wind plasma, and interpret the complex in-situ measurements made by Rosetta, numerical or analytical models are necessary. We use an extended analytical formalism describing solar wind charge-changing processes at comets along solarwind streamlines. The model is driven by solar wind ion measurements from the Rosetta Plasma Consortium-Ion Composition Analyzer (RPC-ICA) and neutral density observations from the Rosetta Spectrometer for Ion and Neutral Analysis-Comet Pressure Sensor (ROSINA-COPS), as well as charge-changing cross sections of hydrogen and helium particles in a water gas. A mission-wide overview of charge-changing efficiencies at comet 67P is presented. Electron capture cross sections dominate and favor the production of He and H energetic neutral atoms, with fluxes expected to rival those of H+ and He2+ ions. Neutral outgassing rates are retrieved from local RPC-ICA flux measurements, and match ROSINA's estimates very well. From the model, we find that solar wind charge exchange is unable to fully explain the magnitude of the sharp drop of solar wind ion fluxes observed by Rosetta for heliocentric distances below 2.5 AU. This is likely because the model does not take into account the relative ion dynamics and, to a lesser extent, ignore the formation of bow shock-like structures upstream of the nucleus. This work also shows that the ionization by solar EUV radiation and energetic electrons dominates the source of cometary ions, although solar wind contributions may be significant during isolated events.

AB - Solar wind charge-changing reactions are of paramount importance to thephysico-chemistry of the atmosphere of a comet. The ESA/Rosetta missionto comet 67P/Churyumov-Gerasimenko (67P) provides a unique opportunity to study charge-changing processes in situ. To understand the role of these reactions in the evolution of the solar wind plasma, and interpret the complex in-situ measurements made by Rosetta, numerical or analytical models are necessary. We use an extended analytical formalism describing solar wind charge-changing processes at comets along solarwind streamlines. The model is driven by solar wind ion measurements from the Rosetta Plasma Consortium-Ion Composition Analyzer (RPC-ICA) and neutral density observations from the Rosetta Spectrometer for Ion and Neutral Analysis-Comet Pressure Sensor (ROSINA-COPS), as well as charge-changing cross sections of hydrogen and helium particles in a water gas. A mission-wide overview of charge-changing efficiencies at comet 67P is presented. Electron capture cross sections dominate and favor the production of He and H energetic neutral atoms, with fluxes expected to rival those of H+ and He2+ ions. Neutral outgassing rates are retrieved from local RPC-ICA flux measurements, and match ROSINA's estimates very well. From the model, we find that solar wind charge exchange is unable to fully explain the magnitude of the sharp drop of solar wind ion fluxes observed by Rosetta for heliocentric distances below 2.5 AU. This is likely because the model does not take into account the relative ion dynamics and, to a lesser extent, ignore the formation of bow shock-like structures upstream of the nucleus. This work also shows that the ionization by solar EUV radiation and energetic electrons dominates the source of cometary ions, although solar wind contributions may be significant during isolated events.

KW - Comets: General

KW - comets: individual: 67P / Churyumov-Gerasimenko

KW - instrumentation: detectors

KW - solar wind, methods: analytical

KW - solar wind: charge-exchange processes

U2 - 10.1051/0004-6361/201834881

DO - 10.1051/0004-6361/201834881

M3 - Article

VL - 630

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

M1 - A37

ER -

ID: 32239158