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62 results on '"Bieler, Andre"'

54. Comparison of 3D kinetic and hydrodynamic models to ROSINA-COPS measurements of the neutral coma of 67P/Churyumov-Gerasimenko

Author

Bieler, Andre, Altwegg, Kathrin, Balsiger, Hans, Berthelier, Jean-Jacques, Calmonte, Ursina Maria, Combi, Michael, De Keyser, Johan, Fiethe, Björn, Fougere, Nicolas, Fuselier, Stephen, Gasc, Sébastien, Gombosi, Tamas, Hansen, Kenneth, Hässig, Myrtha, Huang, Zhenguang, Jäckel, Annette, Jia, Xianzhe, Le Roy, Lena, Mall, Urs A., Rème, Henri, Rubin, Martin, Tenishev, Valeriy, Tóth, Gábor, Tzou, Chia-Yu, and Wurz, Peter

Subjects
13. Climate action, 520 Astronomy, 620 Engineering
Abstract

67P/Churyumov-Gerasimenko (67P) is a Jupiter-family comet and the object of investigation of the European Space Agency mission Rosetta. This report presents the first full 3D simulation results of 67P’s neutral gas coma. In this study we include results from a direct simulation Monte Carlo method, a hydrodynamic code, and a purely geometric calculation which computes the total illuminated surface area on the nucleus. All models include the triangulated 3D shape model of 67P as well as realistic illumination and shadowing conditions. The basic concept is the assumption that these illumination conditions on the nucleus are the main driver for the gas activity of the comet. As a consequence, the total production rate of 67P varies as a function of solar insolation. The best agreement between the model and the data is achieved when gas fluxes on the night side are in the range of 7% to 10% of the maximum flux, accounting for contributions from the most volatile components. To validate the output of our numerical simulations we compare the results of all three models to in situ gas number density measurements from the ROSINA COPS instrument. We are able to reproduce the overall features of these local neutral number density measurements of ROSINA COPS for the time period between early August 2014 and January 1 2015 with all three models. Some details in the measurements are not reproduced and warrant further investigation and refinement of the models. However, the overall assumption that illumination conditions on the nucleus are at least an important driver of the gas activity is validated by the models. According to our simulation results we find the total production rate of 67P to be constant between August and November 2014 with a value of about 1 × 10²⁶ molecules s⁻¹.

55. Expected constraints on the outer solar system formation conditions from the Rosetta-ROSINA measurements

Author

Mousis, Olivier, Altwegg, Kathrin, Balsiger, Hans, Bar-Nun, Akiva, Bertaux, Jean-Loup, Berthelier, Jean-Jacques, Bieler, Andre, Bochsler, Peter, Briois, Christelle, Calmonte, Ursina, Combi, Michael, Johan De Keyser, Dhooghe, Frederik, Fiethe, Björn, Fuselier, Stephen, Gasc, Sébastien, Gliem, Fritz, Gombosi, Tamas, Hässig, Myrtha, Jäckel, Annette, Kopp, Ernest, Korth, Axel, Le Roy, Lena, Mall, Urs, Marty, Bernard, Rème, Henri, Rubin, Martin, Sauvaud, Jean-Andre, Waite, Jack, Wurz, Peter, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Physikalisches Institut [Bern], Universität Bern [Bern], Department of Geosciences [Tel Aviv], Tel Aviv University [Tel Aviv], PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Laboratoire de physique et chimie de l'environnement (LPCE), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Space Science Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), Institut fur Datenverarbeitung, Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Université de Lorraine (UL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille ( LAM ), Centre National de la Recherche Scientifique ( CNRS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Aix Marseille Université ( AMU ) -Centre National d'Etudes Spatiales ( CNES ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), Laboratoire de physique et chimie de l'environnement ( LPCE ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Technische Universität Braunschweig [Braunschweig], Southwest Research Institute [San Antonio] ( SwRI ), Max Planck Institute for Solar System Research ( MPS ), Centre de Recherches Pétrographiques et Géochimiques ( CRPG ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern] (UNIBE), Department of Geophysics [Tel Aviv] (TAU), Tel Aviv University (TAU), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Cardon, Catherine

Subjects
[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], [SDU.ASTR.SR] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Abstract

International audience; Formation scenarios of the protosolar nebula invoke two main reservoirs of ices that took part in the production of icy planetesimals. The first reservoir, located within the inner region of the protosolar nebula, contains ices (dominated by H2O, CO, CO2, CH4, N2 and NH3) originating from the ISM, which, due to their near solar vicinity, were initially vaporized. With time, the decrease of temperature and pressure allowed the water in this reservoir to condense at ~150 K in the form of crystalline ice. It is postulated that a substantial fraction of the volatile species were trapped as clathrates during this condensation phase as long as free water ice was available and there was enough time to overcome the slow kinetics of clathration. On the other hand, the remaining volatiles that were not enclathrated (due to the lack of available water ice or a low kinetics of clathration) probably formed pure condensates at lower temperatures in this part of the nebula. The second reservoir, located at larger heliocentric distances, is composed of ices originating from the ISM that did not vaporize when entering into the disk. In this reservoir, water ice was essentially in the amorphous form and the other volatiles remained trapped in the amorphous matrix. The location of the boundary between these two reservoirs is loosely constrained and may vary between 5 and 30 AU from the Sun, depending on the postulated nebula’s thermodynamic conditions. The uncertainty in the distance of the boundary implies that comets may have formed from amorphous ice as well as from crystalline ices and/or clathrates. Here we review the key in situ measurements that are within the capabilities of the ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instrument aboard the Rosetta spacecraft during its approach of comet 67P/Churyumov-Gerasimenko. These key measurements may allow disentangling between the different formation scenarios.

57. Capitalism’s Crises

Author

Bieler, Andreas, Carroll, William K., Christie, Isham, Damodaran, Sumsngala, Heywood, Mark, Hunt-Hendrix, Leah, Jordan, Jamie, Saad-Filho, Alfredo, Reddy, Niall, Wainwright, Hilary, and Satgar, Vishwas

Subjects
politics & government, international relations, bic Book Industry Communication::J Society & social sciences::JP Politics & government, bic Book Industry Communication::J Society & social sciences::JP Politics & government::JPS International relations
Abstract

"The contributors to this volume draw on a non-dogmatic Marxist approach to explain the systemic and conjunctural dynamics of crisis inherent in global capitalism. Their analysis asks what is historically specific to capitalism's crises while avoiding catastrophic or defeatist claims. At the same time the volume situates left agency within actual patterns of resistance and class struggle to clarify the potential for transformative change. The cycle of resistance strengthened by the World Socal Forum and transnational activism is now punctuated by the experience of the Arab Spring, the agency of anti-systemic movements, left think tanks, the Occupy Wall Street Movement, labour unions, left parties in Europe such as Syrizia and Podemos and peoples' budgeting in Kerala, India. On the down side, we are witnessing the waning of the Workers Party in Brazil and serious challenges for South Africa's once powerful labour movement and still formative social justice activism. All these developments are assessed in this volume. This is the second volume in the Democratic Marxism series. It elaborates on crucial themes introduced in the first volume, Marxism in the 21st Century: Crisis, Critique and Struggle (edited by Michelle Williams and Vishwas Satgar)."

Published
2015
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58. Le problème de la population (Book).

Author

Bieler, Andre

Subjects
*POPULATION, *NONFICTION
Abstract

Reviews the book 'Le Probleme De La Population: Une Interpellation aux Hommes De Notre Temps.'

Published
1976

59. Saint-Irénée

Author

Biéler, André and National Gallery of Canada

Subjects
North American, Canadian
Published
1932

62. Prebiotic chemicals-amino acid and phosphorus-in the coma of comet 67P/Churyumov-Gerasimenko.

Author

Altwegg K, Balsiger H, Bar-Nun A, Berthelier JJ, Bieler A, Bochsler P, Briois C, Calmonte U, Combi MR, Cottin H, De Keyser J, Dhooghe F, Fiethe B, Fuselier SA, Gasc S, Gombosi TI, Hansen KC, Haessig M, Jäckel A, Kopp E, Korth A, Le Roy L, Mall U, Marty B, Mousis O, Owen T, Rème H, Rubin M, Sémon T, Tzou CY, Hunter Waite J, and Wurz P

Subjects
Mass Spectrometry methods, Amino Acids chemistry, Meteoroids, Phosphorus chemistry, Prebiotics analysis
Abstract

The importance of comets for the origin of life on Earth has been advocated for many decades. Amino acids are key ingredients in chemistry, leading to life as we know it. Many primitive meteorites contain amino acids, and it is generally believed that these are formed by aqueous alterations. In the collector aerogel and foil samples of the Stardust mission after the flyby at comet Wild 2, the simplest form of amino acids, glycine, has been found together with precursor molecules methylamine and ethylamine. Because of contamination issues of the samples, a cometary origin was deduced from the (13)C isotopic signature. We report the presence of volatile glycine accompanied by methylamine and ethylamine in the coma of 67P/Churyumov-Gerasimenko measured by the ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) mass spectrometer, confirming the Stardust results. Together with the detection of phosphorus and a multitude of organic molecules, this result demonstrates that comets could have played a crucial role in the emergence of life on Earth.

Published
2016
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