10 results on '"Dhooghe F."'
Search Results
2. Comparison of neutral outgassing of comet 67P/Churyumov-Gerasimenko inbound and outbound beyond 3 AU from ROSINA/DFMS
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Luspay-Kuti, A., primary, Altwegg, K., additional, Berthelier, J. J., additional, Beth, A., additional, Dhooghe, F., additional, Fiethe, B., additional, Fuselier, S. A., additional, Gombosi, T. I., additional, Hansen, K. C., additional, Hässig, M., additional, Livadiotis, G., additional, Mall, U., additional, Mandt, K. E., additional, Mousis, O., additional, Petrinec, S. M., additional, Rubin, M., additional, Trattner, K. J., additional, Tzou, C.-Y., additional, and Wurz, P., additional more...
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- 2019
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3. Isotopic composition of CO₂ in the coma of 67P/Churyumov-Gerasimenko measured with ROSINA/DFMS
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Mandt, K., Hässig, M., Balsiger, Hans, Wampfler, Susanne, Bieler, André, Rubin, Martin, Gasc, Sébastien, Altwegg, Kathrin, Berthelier, J. J., Wurz, Peter, Dhooghe, F., Gombosi, T. I., Fuselier, S. A., Fiethe, B., Tzou, Chia-Yu, Calmonte, Ursina Maria, Le Roy, Léna, and Luspay-Kuti, A. more...
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520 Astronomy ,620 Engineering - Abstract
Measurements of isotopic abundances in cometary ices are key to understanding and reconstructing the history and origin of material in the solar system. Comets are considered the most pristine material in the solar system. Isotopic fractionation (enrichment of an isotope in a molecule compared to the initial abundance) is sensitive to environmental conditions at the time of comet formation. Therefore, measurements of cometary isotope ratios can provide information on the composition, density, temperature, and radiation during formation of the molecules, during the chemical evolution from the presolar cloud to the protosolar nebula, and the protoplanetary disk before accretion in solid bodies. Most isotopic abundances of ¹²C/¹³C and ¹⁶O/¹⁸O in comets to date are in agreement with terrestrial abundances. Prior to the Rosetta mission, measurements of ¹²C/¹³C in comets were only available for HCN, CN, and C₂ and for ¹⁶O/¹⁸O in H₂O. Measurements of ¹²C/¹³C in comets were only available from ground based observations and remote sensing, while ¹⁶O/¹⁸O in H₂O had also been measured in-situ. To date, no measurements of the CO2 isotopologues in comets were available. Aims. This paper presents the first measurements of the CO₂ isotopologues in the coma of 67P/Churyumov-Gerasimenko (67P). Methods. We analyzed measurements taken by the Double Focusing Mass Spectrometer (DFMS) of the ROSINA experiment on board the ESA spacecraft Rosetta in the coma of 67P. Results. The CO₂ isotopologues results for 67P are: ¹²C/¹³C = 84 ± 4, ¹⁶O/¹⁸O = 494 ± 8, and ¹³C¹⁶O2/¹²C¹⁸O¹⁶O = 5:87 ± 0:07. The oxygen isotopic ratio is within error bars compatible with terrestrial abundances but not with solar wind measurements. Conclusions. The carbon isotopic ratio and the combined carbon and oxygen isotopic ratio are slightly (14%) enriched in ¹³C, within 1δ uncertainty, compared to solar wind abundances and solar abundances. The small fractionation of ¹²C/¹³C in CO₂ is probably compatible with an origin of the material in comets from the native cloud. more...
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- 2017
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4. Isotopic composition of CO2in the coma of 67P/Churyumov-Gerasimenko measured with ROSINA/DFMS
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Hässig, M., primary, Altwegg, K., additional, Balsiger, H., additional, Berthelier, J. J., additional, Bieler, A., additional, Calmonte, U., additional, Dhooghe, F., additional, Fiethe, B., additional, Fuselier, S. A., additional, Gasc, S., additional, Gombosi, T. I., additional, Le Roy, L., additional, Luspay-Kuti, A., additional, Mandt, K., additional, Rubin, M., additional, Tzou, C.-Y., additional, Wampfler, S. F., additional, and Wurz, P., additional more...
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- 2017
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5. Ion acoustic waves at comet 67P/Churyumov-Gerasimenko
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Gunell, H., primary, Nilsson, H., additional, Hamrin, M., additional, Eriksson, A., additional, Odelstad, E., additional, Maggiolo, R., additional, Henri, P., additional, Vallieres, X., additional, Altwegg, K., additional, Tzou, C.-Y., additional, Rubin, M., additional, Glassmeier, K.-H., additional, Stenberg Wieser, G., additional, Simon Wedlund, C., additional, De Keyser, J., additional, Dhooghe, F., additional, Cessateur, G., additional, and Gibbons, A., additional more...
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- 2017
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6. Composition-dependent outgassing of comet 67P/Churyumov-Gerasimenko from ROSINA/DFMS
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Balsiger, Hans, Tzou, Chia-Yu, Hässig, Myrtha, Dhooghe, F., Fiethe, B., Fuselier, S. A., Luspay-Kuti, A., Rubin, Martin, Gombosi, T. I., Mall, U., Berthelier, J. J., Altwegg, Kathrin, Gasc, Sébastien, Le Roy, Léna, Wurz, Peter, Mandt, K. E., Mousis, O., and Jäckel, Annette more...
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530 Physics ,520 Astronomy ,620 Engineering - Abstract
Context. Early measurements of Rosetta’s target comet, 67P/Churyumov-Gerasimenko (67P), showed a strongly heterogeneous coma in H2O, CO, and CO2. Aims. The purpose of this work is to further investigate the coma heterogeneity of 67P, and to provide predictions for the near-perihelion outgassing profile based on the proposed explanations. Methods. Measurements of various minor volatile species by ROSINA/DFMS on board Rosetta are examined. The analysis focuses on the currently poorly illuminated winter (southern) hemisphere of 67P. Results. Coma heterogeneity is not limited to the major outgassing species. Minor species show better correlation with either H2O or CO2. The molecule CH4 shows a different diurnal pattern from all other analyzed species. Such features have implications for nucleus heterogeneity and thermal processing. Conclusions. Future analysis of additional volatiles and modeling the heterogeneity are required to better understand the observed coma profile. more...
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- 2015
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7. Composition-dependent outgassing of comet 67P/Churyumov-Gerasimenko from ROSINA/DFMS
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Luspay-Kuti, A., primary, Hässig, M., additional, Fuselier, S. A., additional, Mandt, K. E., additional, Altwegg, K., additional, Balsiger, H., additional, Gasc, S., additional, Jäckel, A., additional, Le Roy, L., additional, Rubin, M., additional, Tzou, C.-Y., additional, Wurz, P., additional, Mousis, O., additional, Dhooghe, F., additional, Berthelier, J. J., additional, Fiethe, B., additional, Gombosi, T. I., additional, and Mall, U., additional more...
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- 2015
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8. Isotopic composition of CO2 in the coma of 67P/Churyumov-Gerasimenko measured with ROSINA/DFMS.
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Hässig, M., Altwegg, K., Balsiger, H., Berthelier, J. J., Bieler, A., Calmonte, U., Dhooghe, F., Fiethe, B., Fuselier, S. A., Gasc, S., Gombosi, T. I., Le Roy, L., Luspay-Kuti, A., Mandt, K., Rubin, M., Tzou, C.-Y., Wampfler, S. F., and Wurz, P. more...
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COMET formation ,ISOTOPIC fractionation ,SOLAR evolution ,SOLAR system ,PROTOPLANETARY disks ,ISOTOPOLOGUES - Abstract
Context. Measurements of isotopic abundances in cometary ices are key to understanding and reconstructing the history and origin of material in the solar system. Comets are considered the most pristine material in the solar system. Isotopic fractionation (enrichment of an isotope in a molecule compared to the initial abundance) is sensitive to environmental conditions at the time of comet formation. Therefore, measurements of cometary isotope ratios can provide information on the composition, density, temperature, and radiation during formation of the molecules, during the chemical evolution from the presolar cloud to the protosolar nebula, and the protoplanetary disk before accretion in solid bodies. Most isotopic abundances of
12 C/13 C and16 O/18 O in comets to date are in agreement with terrestrial abundances. Prior to the Rosetta mission, measurements of12 C/13 C in comets were only available for HCN, CN, and C2 and for16 O/18 O in H2 O. Measurements of12 C/13 C in comets were only available from ground based observations and remote sensing, while16 O/18 O in H2 O had also been measured in-situ. To date, no measurements of the CO2 isotopologues in comets were available. Aims. This paper presents the first measurements of the CO2 isotopologues in the coma of 67P/Churyumov-Gerasimenko (67P). Methods. We analyzed measurements taken by the Double Focusing Mass Spectrometer (DFMS) of the ROSINA experiment on board the ESA spacecraft Rosetta in the coma of 67P. Results. The CO2 isotopologues results for 67P are:12 C/13 C = 84 ± 4,16 O/18 O = 494 ± 8, and13 C16 O2 /16 C18 O16 O = 5.87 ± 0.07. The oxygen isotopic ratio is within error bars compatible with terrestrial abundances but not with solar wind measurements. Conclusions. The carbon isotopic ratio and the combined carbon and oxygen isotopic ratio are slightly (14%) enriched in 13C, within 1σ uncertainty, compared to solar wind abundances and solar abundances. The small fractionation of12 C/13 C in CO2 is probably compatible with an origin of the material in comets from the native cloud. [ABSTRACT FROM AUTHOR] more...- Published
- 2017
- Full Text
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9. Ion acoustic waves at comet 67P/Churyumov-Gerasimenko
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Nilsson, H., De Keyser, J., Vallieres, X., Dhooghe, F., Henri, P., Altwegg, Kathrin, Glassmeier, K.-H., Stenberg Wieser, G., Gibbons, A., Eriksson, A., Tzou, Chia-Yu, Gunell, H., Hamrin, M., Simon Wedlund, C., Cessateur, G., Maggiolo, R., Odelstad, E., and Rubin, Martin more...
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Physics::Plasma Physics ,13. Climate action ,520 Astronomy ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,620 Engineering ,7. Clean energy - Abstract
On 20 January 2015 the Rosetta spacecraft was at a heliocentric distance of 2.5AU, 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, kBTi = 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. more...
10. Comparison of neutral outgassing of comet 67P/Churyumov-Gerasimenko inbound and outbound beyond 3 AU from ROSINA/DFMS
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Luspay-Kuti, A., Altwegg, Kathrin, Berthelier, J. J., Beth, A., Dhooghe, F., Fiete, B., Fuselier, S. A., Gombosi, T. I., Hansen, K. C., Haessig, M., Livadiotis, G., Mall, U., Mandt, K. E., Mousis, O., Petrinec, S. M., Rubin, Martin, Trattner, K. J., Tzou, Chia-Yu, and Wurz, Peter more...
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13. Climate action ,520 Astronomy ,620 Engineering - Abstract
Context. Pre-equinox measurements of comet 67P/Churyumov-Gerasimenko with the mass spectrometer ROSINA/DFMS on board the Rosetta spacecraft revealed a strongly heterogeneous coma. The abundances of major and various minor volatile species were found to depend on the latitude and longitude of the nadir point of the spacecraft. The observed time variability of coma species remained consistent for about three months up to equinox. The chemical variability could be generally interpreted in terms of surface temperature and seasonal effects superposed on some kind of chemical heterogeneity of the nucleus. Aims. We compare here pre-equinox (inbound) ROSINA/DFMS measurements from 2014 to measurements taken after the outbound equinox in 2016, both at heliocentric distances larger than 3 AU. For a direct comparison we limit our observations to the southern hemisphere. Methods. We report the similarities and differences in the concentrations and time variability of neutral species under similar insolation conditions (heliocentric distance and season) pre- and post-equinox, and interpret them in light of the previously published observations. In addition, we extend both the pre- and post-equinox analysis by comparing species concentrations with a mixture of CO₂ and H₂O. Results. Our results show significant changes in the abundances of neutral species in the coma from pre- to post-equinox that are indicative of seasonally driven nucleus heterogeneity. Conclusions. The observed pre- and post-equinox patterns can generally be explained by the strong erosion in the southern hemisphere that moves volatile-rich layers near the surface. more...
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