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Energy conversion i...
Energy conversion in cometary atmospheres Hybrid modeling of 67P/Churyumov-Gerasimenko
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- Lindkvist, Jesper, 1986- (author)
- Umeå universitet,Institutionen för fysik
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- Hamrin, Maria, 1972- (author)
- Umeå universitet,Institutionen för fysik
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- Gunell, Herbert (author)
- Umeå universitet,Institutionen för fysik,Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium
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- Nilsson, H. (author)
- Swedish Inst Space Phys, Kiruna, Sweden.,Swedish Institute of Space Physics
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- Wedlund, C. S. (author)
- Univ Oslo, Dept Phys, Oslo, Norway.,University of Oslo, Department of Physics, Oslo, Norway
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- Kallio, E. (author)
- Aalto Univ, Dept Elect & Nanoengn, Espoo, Finland.,Aalto University, Department of Electronics and Nanoengineering, Espoo, Finland
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- Mann, I. (author)
- Univ Tromso, Dept Phys & Technol, Tromso, Norway.,University of Tromsø, Department of Physics and Technology, Tromsø, Norway
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- Pitkänen, Timo, 1979- (author)
- Umeå universitet,Institutionen för fysik
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- Karlsson, Tomas, 1964- (author)
- KTH,Rymd- och plasmafysik,KTH Royal Institute of Technology, School of Electrical Engineering, Stockholm, Sweden
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(creator_code:org_t)
- 2018-08-21
- 2018
- English.
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 616
- Related links:
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https://www.aanda.or...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Subject headings
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- Aims. We wish to investigate the energy conversion between particles and electromagnetic fields and determine the location where it occurs in the plasma environment of comets. Methods. We used a hybrid plasma model that included photoionization, and we considered two cases of the solar extreme ultraviolet flux. Other parameters corresponded to the conditions of comet 67P/Churyumov-Gerasimenko at a heliocentric distance of 1.5 AU. Results. We find that a shock-like structure is formed upstream of the comet and acts as an electromagnetic generator, similar to the bow shock at Earth that slows down the solar wind. The Poynting flux transports electromagnetic energy toward the inner coma, where newly born cometary ions are accelerated. Upstream of the shock-like structure, we find local energy transfer from solar wind ions to cometary ions. We show that mass loading can be a local process with a direct transfer of energy, but also part of a dynamo system with electromagnetic generators and loads. Conclusions. The energization of cometary ions is governed by a dynamo system for weak ionization, but changes into a large conversion region with local transfer of energy directly from solar wind protons for high ionization.
Subject headings
- NATURVETENSKAP -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)
Keyword
- comets: individual: 67P/Churyumov-Gerasimenko
- Sun: UV radiation
- solar wind
- methods: numerical
- plasmas
- acceleration of particles
Publication and Content Type
- ref (subject category)
- art (subject category)
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- By the author/editor
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Lindkvist, Jespe ...
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Hamrin, Maria, 1 ...
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Gunell, Herbert
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Nilsson, H.
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Wedlund, C. S.
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Kallio, E.
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Mann, I.
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Pitkänen, Timo, ...
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Karlsson, Tomas, ...
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- About the subject
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- NATURAL SCIENCES
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NATURAL SCIENCES
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and Physical Science ...
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and Fusion Plasma an ...
- Articles in the publication
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Astronomy and As ...
- By the university
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Royal Institute of Technology
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Umeå University