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Goldstein, R., Burch, J. L., Llera, K., Mokashi, P., Nilsson, H., Dokgo, K., . . . Richter, I. (2019). Electron acceleration at comet 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics, 630, Article ID A40.
Open this publication in new window or tab >>Electron acceleration at comet 67P/Churyumov-Gerasimenko
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2019 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 630, article id A40Article in journal (Refereed) Published
Abstract [en]

We report the observation by the Ion and Electron Sensor (IES) of energetic (>1 keV) electrons in the plasma environment of comet 67P Churyumov-Gerasimenko (67P). Most of the electrons in the cometary coma are expected to be of solar wind, photoionization, or electron impact origin and are therefore not expected to exceed some hundreds of eV in energy. During the Vega flybys of comet Halley, 1 keV electrons were also observed, and these are explained as having been accelerated by lower hybrid (LH) waves resulting from the two-stream instability involving the solar wind and pickup-ion flows. These waves resonate with the cyclotron motion of the ions and the longitudinal motion of electrons and are on the order of several Hz, at least in the case of 67P. We postulate that the energetic electrons we have observed intermittently during December 2015 through January 2016 are also the result of such a process and that Landau damping causes the acceleration and subsequent abrupt decrease in this energy (also seen at Halley). We show from this study an event on 19 January 2016 when IES simultaneously observed accelerated electrons, solar wind protons, water ions, and LH waves. A dispersion analysis shows that the ion-ion two-stream instability has positive growth rates for such waves during the observation period.

Place, publisher, year, edition, pages
EDP SCIENCES S A, 2019
Keywords
plasmas, waves, methods: data analysis, comets: individual: 67P/Churyumov-Gerasimenko
National Category
Fusion, Plasma and Space Physics Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-395681 (URN)10.1051/0004-6361/201834701 (DOI)000486989400039 ()
Funder
Swedish National Space Board
Available from: 2019-10-24 Created: 2019-10-24 Last updated: 2019-10-24Bibliographically approved
Odelstad, E., Eriksson, A. I., Johansson, F. L., Vigren, E., Henri, P., Gilet, N., . . . André, M. (2018). Ion Velocity and Electron Temperature Inside and Around the Diamagnetic Cavity of Comet 67P. Journal of Geophysical Research - Space Physics, 123(7), 5870-5893
Open this publication in new window or tab >>Ion Velocity and Electron Temperature Inside and Around the Diamagnetic Cavity of Comet 67P
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2018 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 123, no 7, p. 5870-5893Article in journal (Refereed) Published
Abstract [en]

Abstract A major point of interest in cometary plasma physics has been the diamagnetic cavity, an unmagnetized region in the innermost part of the coma. Here we combine Langmuir and Mutual Impedance Probe measurements to investigate ion velocities and electron temperatures in the diamagnetic cavity of comet 67P, probed by the Rosetta spacecraft. We find ion velocities generally in the range 2?4 km/s, significantly above the expected neutral velocity 1 km/s, showing that the ions are (partially) decoupled from the neutrals, indicating that ion-neutral drag was not responsible for balancing the outside magnetic pressure. Observations of clear wake effects on one of the Langmuir probes showed that the ion flow was close to radial and supersonic, at least with respect to the perpendicular temperature, inside the cavity and possibly in the surrounding region as well. We observed spacecraft potentials  V throughout the cavity, showing that a population of warm (?5 eV) electrons was present throughout the parts of the cavity reached by Rosetta. Also, a population of cold ( ) electrons was consistently observed throughout the cavity, but less consistently in the surrounding region, suggesting that while Rosetta never entered a region of collisionally coupled electrons, such a region was possibly not far away during the cavity crossings.

Place, publisher, year, edition, pages
American Geophysical Union (AGU), 2018
Keywords
comets, Rosetta, plasma, diamagnetic cavity, ion velocity, electron temperature
National Category
Astronomy, Astrophysics and Cosmology
Research subject
Physics with specialization in Space and Plasma Physics
Identifiers
urn:nbn:se:uu:diva-356424 (URN)10.1029/2018JA025542 (DOI)000442664300043 ()
Funder
Swedish National Space Board, 109/12, 168/15, 166/14Swedish Research Council, 621-2013-4191
Note

Article published in Early View on 25 July, 2018

Available from: 2018-07-26 Created: 2018-07-26 Last updated: 2018-11-05Bibliographically approved
Engelhardt, I. A. A., Eriksson, A., Stenberg Wieser, G., Goetz, C., Rubin, M., Henri, P., . . . Valliéres, X. (2018). Plasma Density Structures at Comet 67P/Churyumov-Gerasimenko. Monthly notices of the Royal Astronomical Society, 477(1), 1296-1307
Open this publication in new window or tab >>Plasma Density Structures at Comet 67P/Churyumov-Gerasimenko
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2018 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 477, no 1, p. 1296-1307Article in journal (Refereed) Published
Abstract [en]

We present Rosetta RPC case study from four events at various radial distance, phase angle and local time from autumn 2015, just after perihelion of comet 67P/Churyumov-Gerasimenko. Pulse like (high amplitude, up to minutes in time) signatures are seen with several RPC instruments in the plasma density (LAP, MIP), ion energy and flux (ICA) as well as magnetic field intensity (MAG). Furthermore the cometocentric distance relative to the electron exobase is seen to be a good organizing parameter for the measured plasma variations. The closer Rosetta is to this boundary, the more pulses are measured. This is consistent with the pulses being filaments of plasma originating from the diamagnetic cavity boundary as predicted by simulations. 

National Category
Fusion, Plasma and Space Physics
Research subject
Physics with specialization in Space and Plasma Physics; Physics
Identifiers
urn:nbn:se:uu:diva-347003 (URN)10.1093/mnras/sty765 (DOI)000432660300090 ()
Funder
Swedish National Space Board, 171/12Swedish National Space Board, 109/12
Available from: 2018-04-18 Created: 2018-04-18 Last updated: 2018-08-20Bibliographically approved
Eriksson, A. I., Engelhardt, I. A. A., André, M., Boström, R., Edberg, N. J. T., Johansson, F. L., . . . Norberg, C. (2017). Cold and warm electrons at comet 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics, 605, Article ID A15.
Open this publication in new window or tab >>Cold and warm electrons at comet 67P/Churyumov-Gerasimenko
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2017 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 605, article id A15Article in journal (Refereed) Published
Abstract [en]

Context. Strong electron cooling on the neutral gas in cometary comae has been predicted for a long time, but actual measurements of low electron temperature are scarce. Aims. Our aim is to demonstrate the existence of cold electrons in the inner coma of comet 67P/Churyumov-Gerasimenko and show filamentation of this plasma.

Methods. In situ measurements of plasma density, electron temperature and spacecraft potential were carried out by the Rosetta Langmuir probe instrument, LAP. We also performed analytical modelling of the expanding two-temperature electron gas.

Results. LAP data acquired within a few hundred km from the nucleus are dominated by a warm component with electron temperature typically 5-10 eV at all heliocentric distances covered (1.25 to 3.83 AU). A cold component, with temperature no higher than about 0.1 eV, appears in the data as short (few to few tens of seconds) pulses of high probe current, indicating local enhancement of plasma density as well as a decrease in electron temperature. These pulses first appeared around 3 AU and were seen for longer periods close to perihelion. The general pattern of pulse appearance follows that of neutral gas and plasma density. We have not identified any periods with only cold electrons present. The electron flux to Rosetta was always dominated by higher energies, driving the spacecraft potential to order -10 V.

Conclusions. The warm (5-10 eV) electron population observed throughout the mission is interpreted as electrons retaining the energy they obtained when released in the ionisation process. The sometimes observed cold populations with electron temperatures below 0.1 eV verify collisional cooling in the coma. The cold electrons were only observed together with the warm population. The general appearance of the cold population appears to be consistent with a Haser-like model, implicitly supporting also the coupling of ions to the neutral gas. The expanding cold plasma is unstable, forming filaments that we observe as pulses.

Keywords
comets: general, plasmas, space vehicles: instruments
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-337755 (URN)10.1051/0004-6361/201630159 (DOI)000412231200111 ()
Funder
Swedish National Space Board, 109/12; 171/12; 135/13; 166/14; 168/15Swedish Research Council, 621-2013-4191
Note

Funding: The results presented here are only possible thanks to the combined efforts over 20 yr by many groups and individuals involved in Rosetta, including but not restricted to the ESA project teams at ESTEC, ESOC and ESAC and all people involved in designing, building, testing and operating RPC and LAP. We thank Kathrin Altwegg for discussions of the pulses in LAP and COPS. Rosetta is a European Space Agency (ESA) mission with contributions from its member states and the National Aeronautics and Space Administration (NASA). The work on RPC-LAP data was funded by the Swedish National Space Board under contracts 109/12, 171/12, 135/13, 166/14 and 168/15, and by Vetenskapsradet under contract 621-2013-4191. This work has made use of the AMDA and RPC Quicklook database, provided by a collaboration between the Centre de Donnees de la Physique des Plasmas CDPP (supported by CNRS, CNES, Observatoire de Paris and Universite Paul Sabatier, Toulouse), and Imperial College London (supported by the UK Science and Technology Facilities Council).

Available from: 2018-01-12 Created: 2018-01-12 Last updated: 2018-04-18Bibliographically approved
Vigren, E., André, M., Edberg, N. J. T., Engelhardt, I. A. A., Eriksson, A., Galand, M., . . . Vallieres, X. (2017). Effective ion speeds at similar to 200-250 km from comet 67P/Churyumov-Gerasimenko near perihelion. Paper presented at International Conference on Cometary Science - Comets - A New Vision after Rosetta and Philae, NOV 14-18, 2016, Toulouse, FRANCE. Monthly notices of the Royal Astronomical Society, 469, S142-S148
Open this publication in new window or tab >>Effective ion speeds at similar to 200-250 km from comet 67P/Churyumov-Gerasimenko near perihelion
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2017 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 469, p. S142-S148Article in journal (Refereed) Published
Abstract [en]

In 2015 August, comet 67P/Churyumov-Gerasimenko, the target comet of the ESA Rosetta mission, reached its perihelion at similar to 1.24 au. Here, we estimate for a three-day period near perihelion, effective ion speeds at distances similar to 200-250 km from the nucleus. We utilize two different methods combining measurements from the Rosetta Plasma Consortium (RPC)/Mutual Impedance Probe with measurements either from the RPC/Langmuir Probe or from the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Comet Pressure Sensor (COPS) (the latter method can only be applied to estimate the effective ion drift speed). The obtained ion speeds, typically in the range 2-8 km s(-1), are markedly higher than the expected neutral outflow velocity of similar to 1 km s(-1). This indicates that the ions were de-coupled from the neutrals before reaching the spacecraft location and that they had undergone acceleration along electric fields, not necessarily limited to acceleration along ambipolar electric fields in the radial direction. For the limited time period studied, we see indications that at increasing distances from the nucleus, the fraction of the ions' kinetic energy associated with radial drift motion is decreasing.

Keywords
molecular processes, comets: individual: 67P/Churyumov-Gerasimenko
National Category
Astronomy, Astrophysics and Cosmology Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-376847 (URN)10.1093/mnras/stx1472 (DOI)000443940500014 ()
Conference
International Conference on Cometary Science - Comets - A New Vision after Rosetta and Philae, NOV 14-18, 2016, Toulouse, FRANCE
Funder
Swedish Research Council, 621-2013-4191Swedish Research Council, 621-2014-5526Swedish National Space Board, 109/02Swedish National Space Board, 135/13Swedish National Space Board, 166/14Swedish National Space Board, 114/13
Available from: 2019-02-12 Created: 2019-02-12 Last updated: 2019-02-12Bibliographically approved
Nilsson, H., Wieser, G. S., Behar, E., Gunell, H., Wieser, M., Galand, M., . . . Vigren, E. (2017). Evolution of the ion environment of comet 67P during the Rosetta mission as seen by RPC-ICA. Paper presented at International Conference on Cometary Science - Comets - A New Vision after Rosetta and Philae, NOV 14-18, 2016, Toulouse, FRANCE. Monthly notices of the Royal Astronomical Society, 469, S252-S261
Open this publication in new window or tab >>Evolution of the ion environment of comet 67P during the Rosetta mission as seen by RPC-ICA
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2017 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 469, p. S252-S261Article in journal (Refereed) Published
Abstract [en]

Rosetta has followed comet 67P from low activity at more than 3.6 au heliocentric distance to high activity at perihelion (1.24 au) and then out again. We provide a general overview of the evolution of the dynamic ion environment using data from the RPC-ICA ion spectrometer. We discuss where Rosetta was located within the evolving comet magnetosphere. For the initial observations, the solar wind permeated all of the coma. In 2015 mid-April, the solar wind started to disappear from the observation region, to re-appear again in 2015 December. Low-energy cometary ions were seen at first when Rosetta was about 100 km from the nucleus at 3.6 au, and soon after consistently throughout the mission except during the excursions to farther distances from the comet. The observed flux of low-energy ions was relatively constant due to Rosetta's orbit changing with comet activity. Accelerated cometary ions, moving mainly in the antisunward direction gradually became more common as comet activity increased. These accelerated cometary ions kept being observed also after the solar wind disappeared from the location of Rosetta, with somewhat higher fluxes further away from the nucleus. Around perihelion, when Rosetta was relatively deep within the comet magnetosphere, the fluxes of accelerated cometary ions decreased, as did their maximum energy. The disappearance of more energetic cometary ions at close distance during high activity is suggested to be due to a flow pattern where these ions flow around the obstacle of the denser coma or due to charge exchange losses.

Place, publisher, year, edition, pages
OXFORD UNIV PRESS, 2017
Keywords
plasmas, methods: data analysis, comets: individual: 67P
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-376699 (URN)10.1093/mnras/stx1491 (DOI)000443940500024 ()
Conference
International Conference on Cometary Science - Comets - A New Vision after Rosetta and Philae, NOV 14-18, 2016, Toulouse, FRANCE
Funder
Swedish Research Council, 2015-04187
Available from: 2019-02-08 Created: 2019-02-08 Last updated: 2019-02-08Bibliographically approved
Hajra, R., Henri, P., Vallieres, X., Galand, M., Heritier, K., Eriksson, A. I., . . . Rubin, M. (2017). Impact of a cometary outburst on its ionosphere Rosetta Plasma Consortium observations of the outburst exhibited by comet 67P/Churyumov-Gerasimenko on 19 February 2016. Astronomy and Astrophysics, 607, Article ID A34.
Open this publication in new window or tab >>Impact of a cometary outburst on its ionosphere Rosetta Plasma Consortium observations of the outburst exhibited by comet 67P/Churyumov-Gerasimenko on 19 February 2016
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2017 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 607, article id A34Article in journal (Refereed) Published
Abstract [en]

We present a detailed study of the cometary ionospheric response to a cometary brightness outburst using in situ measurements for the first time. The comet 67P/Churyumov-Gerasimenko (67P) at a heliocentric distance of 2.4 AU from the Sun, exhibited an outburst at similar to 1000 UT on 19 February 2016, characterized by an increase in the coma surface brightness of two orders of magnitude. The Rosetta spacecraft monitored the plasma environment of 67P from a distance of 30 km, orbiting with a relative speed of similar to 0.2 m s(-1). The onset of the outburst was preceded by pre-outburst decreases in neutral gas density at Rosetta, in local plasma density, and in negative spacecraft potential at similar to 0950 UT. In response to the outburst, the neutral density increased by a factor of similar to 1.8 and the local plasma density increased by a factor of similar to 3, driving the spacecraft potential more negative. The energetic electrons (tens of eV) exhibited decreases in the flux of factors of similar to 2 to 9, depending on the energy of the electrons. The local magnetic field exhibited a slight increase in amplitude (similar to 5 nT) and an abrupt rotation (similar to 36.4 degrees) in response to the outburst. A weakening of 10-100 mHz magnetic field fluctuations was also noted during the outburst, suggesting alteration of the origin of the wave activity by the outburst. The plasma and magnetic field effects lasted for about 4 h, from similar to 1000 UT to 1400 UT. The plasma densities are compared with an ionospheric model. This shows that while photoionization is the main source of electrons, electron-impact ionization and a reduction in the ion outflow velocity need to be accounted for in order to explain the plasma density enhancement near the outburst peak.

Keywords
plasmas, waves, methods: data analysis, methods: observational, comets: general, comets: individual: 67P/Churyumov-Gerasimenko
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-340902 (URN)10.1051/0004-6361/201730591 (DOI)000414474000003 ()
Available from: 2018-02-06 Created: 2018-02-06 Last updated: 2018-03-13Bibliographically approved
Wieser, G. S., Odelstad, E., Wieser, M., Nilsson, H., Goetz, C., Karlsson, T., . . . Gunell, H. (2017). Investigating short-time-scale variations in cometary ions around comet 67P. Paper presented at International Conference on Cometary Science - Comets - A New Vision after Rosetta and Philae, NOV 14-18, 2016, Toulouse, FRANCE. Monthly notices of the Royal Astronomical Society, 469, S522-S534
Open this publication in new window or tab >>Investigating short-time-scale variations in cometary ions around comet 67P
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2017 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 469, p. S522-S534Article in journal (Refereed) Published
Abstract [en]

The highly varying plasma environment around comet 67P/Churyumov-Gerasimenko inspired an upgrade of the ion mass spectrometer (Rosetta Plasma Consortium Ion Composition Analyzer) with new operation modes, to enable high time resolution measurements of cometary ions. Two modes were implemented, one having a 4 s time resolution in the energy range 0.3-82 eV/q and the other featuring a 1 s time resolution in the energy range 13-50 eV/q. Comparing measurements made with the two modes, it was concluded that 4 s time resolution is enough to capture most of the fast changes of the cometary ion environment. The 1462 h of observations done with the 4 s mode were divided into hour-long sequences. It is possible to sort 84 per cent of these sequences into one of five categories, depending on their appearance in an energy-time spectrogram. The ion environment is generally highly dynamic, and variations in ion fluxes and energies are seen on time-scales of 10 s to several minutes.

Keywords
plasmas, instrumentation: detectors, methods: data analysis, methods: statistical, space vehicles: instruments, comets: individual: 67P
National Category
Fusion, Plasma and Space Physics Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-376849 (URN)10.1093/mnras/stx2133 (DOI)000443940500049 ()
Conference
International Conference on Cometary Science - Comets - A New Vision after Rosetta and Philae, NOV 14-18, 2016, Toulouse, FRANCE
Funder
Swedish National Space Board, 96/15Swedish National Space Board, 101/15Swedish National Space Board, 95/15
Available from: 2019-02-12 Created: 2019-02-12 Last updated: 2019-02-12Bibliographically approved
Gunell, H., Nilsson, H., Hamrin, M., Eriksson, A., Odelstad, E., Maggiolo, R., . . . Gibbons, A. (2017). Ion acoustic waves at comet 67P/Churyumov-Gerasimenko: Observations and computations. Astronomy and Astrophysics, 600, Article ID A3.
Open this publication in new window or tab >>Ion acoustic waves at comet 67P/Churyumov-Gerasimenko: Observations and computations
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2017 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 600, article id A3Article in journal (Refereed) Published
Abstract [en]

Context. On 20 January 2015 the Rosetta spacecraft was at a heliocentric distance of 2.5 AU, accompanying comet 67P/Churyumov-Gerasimenko on its journey toward the Sun. The Ion Composition Analyser (RPC-ICA), other instruments of the Rosetta Plasma Consortium, and the ROSINA instrument made observations relevant to the generation of plasma waves in the cometary environment.

Aims. Observations of plasma waves by the Rosetta Plasma Consortium Langmuir probe (RPC-LAP) can be explained by dispersion relations calculated based on measurements of ions by the Rosetta Plasma Consortium Ion Composition Analyser (RPC-ICA), and this gives insight into the relationship between plasma phenomena and the neutral coma, which is observed by the Comet Pressure Sensor of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument (ROSINA-COPS).

Methods. We use the simple pole expansion technique to compute dispersion relations for waves on ion timescales based on the observed ion distribution functions. These dispersion relations are then compared to the waves that are observed. Data from the instruments RPC-LAP, RPC-ICA and the mutual impedance probe (RPC-MIP) are compared to find the best estimate of the plasma density.

Results. We find that ion acoustic waves are present in the plasma at comet 67P/Churyumov-Gerasimenko, where the major ion species is H2O+. The bulk of the ion distribution is cold, k(B)T(i) = 0.01 eV when the ion acoustic waves are observed. At times when the neutral density is high, ions are heated through acceleration by the solar wind electric field and scattered in collisions with the neutrals. This process heats the ions to about 1 eV, which leads to significant damping of the ion acoustic waves.

Conclusions. In conclusion, we show that ion acoustic waves appear in the H2O+ plasmas at comet 67P/Churyumov-Gerasimenko and how the interaction between the neutral and ion populations affects the wave properties.

Place, publisher, year, edition, pages
EDP SCIENCES S A, 2017
Keywords
comets: general, comets: individual: 67P/Churyumov-Gerasimenko, instrumentation: detectors, methods: analytical, plasmas, waves
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-324339 (URN)10.1051/0004-6361/201629801 (DOI)000400754000090 ()
Available from: 2017-06-15 Created: 2017-06-15 Last updated: 2017-06-15Bibliographically approved
Heritier, K. L., Altwegg, K., Balsiger, H., Berthelier, J.-J. -., Beth, A., Bieler, A., . . . Vuitton, V. (2017). Ion composition at comet 67P near perihelion: Rosetta observations and model-based interpretation. Paper presented at International Conference on Cometary Science - Comets - A New Vision after Rosetta and Philae, NOV 14-18, 2016, Toulouse, FRANCE. Monthly notices of the Royal Astronomical Society, 469, S427-S442
Open this publication in new window or tab >>Ion composition at comet 67P near perihelion: Rosetta observations and model-based interpretation
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2017 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 469, p. S427-S442Article in journal (Refereed) Published
Abstract [en]

We present the ion composition in the coma of comet 67P with newly detected ion species over the 28-37 u mass range, probed by Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Double Focusing Mass Spectrometer (DFMS). In summer 2015, the nucleus reached its highest outgassing rate and ion-neutral reactions started to take place at low cometocentric distances. Minor neutrals can efficiently capture protons from the ion population, making the protonated version of these neutrals a major ion species. So far, only NH4+ has been reported at comet 67P. However, there are additional neutral species with proton affinities higher than that of water (besides NH3) that have been detected in the coma of comet 67P: CH3OH, HCN, H2CO and H2S. Their protonated versions have all been detected. Statistics showing the number of detections with respect to the number of scans are presented. The effect of the negative spacecraft potential probed by the Rosetta Plasma Consortium/LAngmuir Probe on ion detection is assessed. An ionospheric model has been developed to assess the different ion density profiles and compare them to the ROSINA/DFMS measurements. It is also used to interpret the ROSINA/DFMS observations when different ion species have similar masses, and their respective densities are not high enough to disentangle them using the ROSINA/DFMS high-resolution mode. The different ion species that have been reported in the coma of 67P are summarized and compared with the ions detected at comet 1P/Halley during the Giotto mission.

Place, publisher, year, edition, pages
OXFORD UNIV PRESS, 2017
Keywords
plasmas, methods: data analysis, Sun: UV radiation, comets: individual: 67P
National Category
Astronomy, Astrophysics and Cosmology Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-376692 (URN)10.1093/mnras/stx1912 (DOI)000443940500042 ()
Conference
International Conference on Cometary Science - Comets - A New Vision after Rosetta and Philae, NOV 14-18, 2016, Toulouse, FRANCE
Available from: 2019-02-14 Created: 2019-02-14 Last updated: 2019-02-14Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-7854-6001

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