Author: "J Crovisier" - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"J Crovisier"' showing total 132 results

Start Over Author "J Crovisier"

132 results on '"J Crovisier"'

1. Gas Sources from the Coma and Nucleus of Comet 46P/Wirtanen Observed Using ALMA

Author: M. A. Cordiner, N. X. Roth, S. N. Milam, G. L. Villanueva, D. Bockelée-Morvan, A. J. Remijan, S. B. Charnley, N. Biver, D. C. Lis, C. Qi, B. P. Bonev, J. Crovisier, and Jeremie Boissier
Subjects: Astrophysics, Astronomy
Abstract: Gas-phase molecules in cometary atmospheres (comae) originate primarily from (1) outgassing by the nucleus, (2) sublimation of icy grains in the near-nucleus coma, and (3) coma (photo)chemical processes. However, the majority of cometary gases observed at radio wavelengths have yet to be mapped, so their production/release mechanisms remain uncertain. Here we present observations of six molecular species toward comet 46P/Wirtanen, obtained using the Atacama Large Millimeter/submillimeter Array during the comet's unusually close (∼0.1 au) approach to Earth in 2018 December. Interferometric maps of HCN, CH3OH, CH3CN, H2CO, CS, and HNC were obtained at an unprecedented sky-projected spatial resolution of up to 25 km, enabling the nucleus and coma sources of these molecules to be accurately quantified. The HCN, CH3OH, and CH3CN spatial distributions are consistent with production by direct outgassing from (or very close to) the nucleus, with a significant proportion of the observed CH3OH originating from sublimation of icy grains in the near-nucleus coma (at a scale length Lp = 36 ± 7 km). On the other hand, H2CO, CS, and HNC originate primarily from distributed coma sources (with Lp values in the range 550–16,000 km), the identities of which remain to be established. The HCN, CH3OH, and HNC abundances in 46P are consistent with the average values previously observed in comets, whereas the H2CO, CH3CN, and CS abundances are relatively low.
Published: 2023
Full Text: View/download PDF

2. Evidence for Surprising Heavy Nitrogen Isotopic Enrichment in Comet 46P/Wirtanen’s Hydrogen Cyanide

Author: M. A. Cordiner, K. Darnell, D. Bockelée-Morvan, N. X. Roth, N. Biver, S. N. Milam, S. B. Charnley, J. Boissier, B. P. Bonev, C. Qi, J. Crovisier, and A. J. Remijan
Subjects: Comets, Neutral coma gases, Comae, Small Solar System bodies, Astrochemistry, Cosmochemistry, Astronomy, QB1-991
Abstract: 46P/Wirtanen is a Jupiter-family comet, probably originating from the solar system’s Kuiper Belt, that now resides on a 5.4 yr elliptical orbit. During its 2018 apparition, comet 46P passed unusually close to the Earth (within 0.08 au), presenting an outstanding opportunity for close-up observations of its inner coma. Here we present observations of HCN, H ^13 CN, and HC ^15 N emission from 46P using the Atacama Compact Array. The data were analyzed using the SUBLIME non-LTE radiative transfer code to derive ^12 C/ ^13 C and ^14 N/ ^15 N ratios. The HCN/H ^13 CN ratio is found to be consistent with a lack of significant ^13 C fractionation, whereas the HCN/HC ^15 N ratio of 68 ± 27 (using our most conservative 1 σ uncertainties), indicates a strong enhancement in ^15 N compared with the solar and terrestrial values. The observed ^14 N/ ^15 N ratio is also significantly lower than the values of ∼140 found in previous comets, implying a strong ^15 N enrichment in 46P’s HCN. This indicates that the nitrogen in Jupiter-family comets could reach larger isotopic enrichments than previously thought, with implications for the diversity of ^14 N/ ^15 N ratios imprinted into icy bodies at the birth of the solar system.
Published: 2024
Full Text: View/download PDF

3. ALMA Autocorrelation Spectroscopy of Comets: the HCN/H13CN Ratio in C/2012 S1 (ISON)

Author: M A Cordiner, M Y Palmer, M de Val-Borro, S B Charnley, L Paganini, G Villanueva, D Bockelee-Morvan, N Biver, A J Remijan, Y J Kuan, S N Milam, J Crovisier, D C Lis, and M J Mumma
Subjects: Astronomy
Abstract: The Atacama Large Millimeter/submillimeter Array (ALMA) is a powerful tool for high-resolution mapping of comets, but the main interferometer (comprised of 50×12-m antennas) is insensitive to the largest coma scales due to a lack of very short baselines. In this work, we present a new technique employing ALMA autocorrelation data (obtained simultaneously with the interferometric observations), effectively treating the entire 12-m array as a collection of single-dish telescopes. Using combined autocorrelation spectra from 28 active antennas, we recovered extended HCN coma emission from comet C/2012 S1 (ISON), resulting in a fourteen-fold increase in detected line brightness compared with the interferometer. This resulted in the first detection of rotational emission from H13CN in this comet. Using a detailed coma radiative transfer model accounting for optical depth and non-LTE excitation effects, we obtained an H12CN/H13CN ratio of 88±18, which matches the terrestrial value of 89, consistent with a lack of isotopic fractionation in HCN during comet formation in the protosolar accretion disk. The possibility of future discoveries in extended sources using autocorrelation spectroscopy from the main ALMA array is thus demonstrated.
Published: 2019
Full Text: View/download PDF

4. Coma composition of comet 67P/Churyumov-Gerasimenko from radio-wave spectroscopy

Author: N. Biver, D. Bockelée-Morvan, J. Crovisier, Aa. Sandqvist, J. Boissier, D. C. Lis, M. Cordiner, B. P. Bonev, N. Dello Russo, R. Moreno, S. Milam, N. X. Roth, R. Vervack, and M. A. DiSanti
Subjects: Space and Planetary Science, Astronomy and Astrophysics
Abstract: We present the results of a molecular survey of comet 67P/Churyumov-Gerasimenko undertaken with the Institut de RadioAstronomie Millimétrique (IRAM) 30-m radio telescope in November–December 2021, when it had its most favourable apparition in decades. Observations at IRAM 30-m during the 12–16 November period covered 8 GHz bandwidth at 3 mm, 16 GHz at 2 mm, and 60 GHz in the 1 mm window domain. These were completed by snapshots at 1 mm on 12–13 December and a short observation of the H2O line at 557 GHz with the Odin sub-millimetre observatory on 17.0 November 2021, and with 18-cm observations of OH with the Nançay radio telescope. Less sensitive observations obtained at a previous perihelion passage on 18–22 September 2015 with IRAM and 9–12 November 2015 with Odin are also presented. The gas outflow velocity, outgassing pattern, and temperature have been accurately constrained by the observations. They are perfectly consistent with those measured in situ with the Rosetta/MIRO sub-millimetre instrument in 2015. In particular, the asymmetry of the line is well represented by a jet concentrating three-quarters of the outgassing in about π steradians. We derived abundances relative to water for seven molecules and significant upper limits for approximately five others. The retrieved abundances were compared to those measured in situ at the previous perihelion with Rosetta. While those of HCN, CH3OH, and HNCO are comparable, 67P is found to be depleted in H2S and relatively normal in CS (H2S/CS ≈ 3) in strong contradiction with the Rosetta/ROSINA mass spectrometer measurement of the H2S/CS2 (≈100) abundance ratio. While the formaldehyde total abundance found with IRAM 30-m when assuming it to be mostly produced by a distributed source (Haser parent scale length ≈8000 km) is similar to the one derived by Rosetta/ROSINA, we find that the formaldehyde coming from the nucleus is one order of magnitude less abundant than measured in situ by Rosetta/ROSINA.
Published: 2023
Full Text: View/download PDF

5. Observations of comet C/2020 F3 (NEOWISE) with IRAM telescopes

Author: N. Biver, J. Boissier, D. Bockelée-Morvan, J. Crovisier, H. Cottin, M. A. Cordiner, N. X. Roth, and R. Moreno
Subjects: Space and Planetary Science, Astronomy and Astrophysics
Abstract: We present the results of millimetre-wave spectroscopic and continuum observations of the comet C/2020 F3 (NEOWISE) undertaken with the Institut de RadioAstronomie Millimétrique (IRAM) 30-m and the NOrthern Extended Millimeter Array (NOEMA) telescopes on 22, 25–27 July, and 7 August 2020. Production rates of HCN, HNC, CH3OH CS, H2CO, CH3CN, H2S, and CO were determined with upper limits on six other species. The comet shows abundances within the range observed for other comets. The CO abundance is low (3.2% relative to water), while H2S is relatively abundant (1.1% relative to water). The H2CO abundance shows a steep variation with heliocentric distance, possibly related to a distributed production from the dust or macro-molecular source. The CH3OH and H2S production rates show a slower decrease post-perihelion than water. There was no detection of the nucleus point source contribution based on the interferometric map of the continuum (implying a size of r < 4.7 km), but this yielded an estimate of the dust production rate, leading to a relatively low dust-to-gas ratio of 0.7 ± 0.3 on 22.4 July 2020.
Published: 2022
Full Text: View/download PDF

6. The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta

Author: F. Capaccioni, A. Coradini, G. Filacchione, S. Erard, G. Arnold, P. Drossart, M. C. De Sanctis, D. Bockelee-Morvan, M. T. Capria, F. Tosi, C. Leyrat, B. Schmitt, E. Quirico, P. Cerroni, V. Mennella, A. Raponi, M. Ciarniello, T. McCord, L. Moroz, E. Palomba, E. Ammannito, M. A. Barucci, G. Bellucci, J. Benkhoff, J. P. Bibring, A. Blanco, M. Blecka, R. Carlson, U. Carsenty, L. Colangeli, M. Combes, M. Combi, J. Crovisier, T. Encrenaz, C. Federico, U. Fink, S. Fonti, W. H. Ip, P. Irwin, R. Jaumann, E. Kuehrt, Y. Langevin, G. Magni, S. Mottola, V. Orofino, P. Palumbo, G. Piccioni, U. Schade, F. Taylor, D. Tiphene, G. P. Tozzi, P. Beck, N. Biver, L. Bonal, J.-Ph. Combe, D. Despan, E. Flamini, S. Fornasier, A. Frigeri, D. Grassi, M. Gudipati, A. Longobardo, K. Markus, F. Merlin, R. Orosei, G. Rinaldi, K. Stephan, M. Cartacci, A. Cicchetti, S. Giuppi, Y. Hello, F. Henry, S. Jacquinod, R. Noschese, G. Peter, R. Politi, J. M. Reess, and A. Semery
Published: 2015
Full Text: View/download PDF

7. Molecular composition of comet 46P/Wirtanen from millimetre-wave spectroscopy

Author: N. Dello Russo, J. Crovisier, P. Colom, Dominique Bockelée-Morvan, Boncho P. Bonev, R. Moreno, Nathan Roth, Martin A. Cordiner, Nicolas Biver, Dariusz C. Lis, Jérémie Boissier, Stefanie N. Milam, Ronald J. Vervack, Michael A. DiSanti, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Instituto Alexander Von Humboldt, Bogota, Colombia, NASA Goddard Space Flight Center (GSFC), Catholic University of America, Universities Space Research Association (USRA), American University Washington D.C. (AU), Johns Hopkins University (JHU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), and GSFC Planetary Systems Laboratory
Subjects: Formamide, 010504 meteorology & atmospheric sciences, Mean kinetic temperature, radio lines: planetary systems, Comet, FOS: Physical sciences, Astrophysics, 01 natural sciences, Radio telescope, chemistry.chemical_compound, 0103 physical sciences, Molecule, Spectroscopy, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Millimetre wave, Earth and Planetary Astrophysics (astro-ph.EP), Physics, comets: general, submillimeter: planetary systems, Astronomy and Astrophysics, chemistry, 13. Climate action, Space and Planetary Science, comets: individual: 46P/Wirtanen, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Ethylene glycol, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the results of a molecular survey of comet 46P/Wirtanen undertaken with the IRAM 30-m and NOEMA radio telescopes in December 2018. Observations at IRAM 30-m during the 12-18 Dec. period comprise a 2 mm spectral survey covering 25 GHz and a 1 mm survey covering 62 GHz. The gas outflow velocity and kinetic temperature have been accurately constrained by the observations. We derive abundances of 11 molecules, some being identified remotely for the first time in a Jupiter-family comet, including complex organic molecules such as formamide, ethylene glycol, acetaldehyde, or ethanol. Sensitive upper limits on the abundances of 24 other molecules are obtained. The comet is found to be relatively rich in methanol (3.4 percent relative to water), but relatively depleted in CO, CS, HNC, HNCO, and HCOOH., Comment: 35 pages, 16 figures, to be published in Astronomy & Astrophysics
Published: 2021
Full Text: View/download PDF

8. Gas terminal velocity from MIRO/Rosetta data using neural network approach

Author: O. Pinzón-Rodríguez, Nicolas Biver, Samuel Gulkis, J. Crovisier, A. Zorzi, David Marshall, W-H. Ip, Paul Hartogh, D. Bockelée-Morvan, Ladislav Rezac, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, German Remote Sensing Data Center (DLR-DFD), German Aerospace Center (DLR), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), and California Institute of Technology (CALTECH)
Subjects: 010504 meteorology & atmospheric sciences, Terminal velocity, Comet, Context (language use), comets: individual: 67P/CG, Astrophysics, 01 natural sciences, Spectral line, law.invention, symbols.namesake, Orbiter, law, 0103 physical sciences, Nadir, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Line (formation), [PHYS]Physics [physics], Physics, comets: general, Astronomy and Astrophysics, methods: data analysis, Computational physics, Space and Planetary Science, symbols, Doppler effect
Abstract: Context. The Microwave Instrument on the Rosetta Orbiter (MIRO) on board the Rosetta spacecraft was designed to investigate the surface and gas activity of the comet 67P/Churyumov-Gerasimenko. The MIRO spectroscopic measurements carry information about the velocity of gas emanating from the nucleus surface. Knowledge of the terminal velocity of the H2O gas is valuable for interpretation of in situ measurements, calibrating 3D coma simulations, and studying the physics of gas acceleration. Aims. Using a neural network technique, we aim to estimate the gas terminal velocity from the entire MIRO dataset of nadir geometry pointings. The velocity of the gas is encoded in the Doppler shift of the measured rotational transitions of o-H216O and o-H218O even when the spectral lines are optically thick with quasi or fully saturated line cores. Methods. Neural networks are robust nonlinear algorithms that can be trained to recognize underlying input to output functional relationships. A training set of about 2200 non-LTE simulated spectra for the two transitions is computed for known input cometary atmospheres, varying column density, temperature, and expansion velocity profiles. Two four-layer networks are used to learn and then predict the gas terminal velocity from the MIRO nadir measured o-H216O and o-H218O spectra lines, respectively. We also quantify the accuracy, stability, and uncertainty of the estimated parameter. Results. Once trained, the neural network is very effective in inverting the measured spectra. We process the entire dataset of MIRO measurements from August 2014 to July 2016, and investigate correlations and temporal evolution of terminal velocities derived from the two spectral lines. The highest terminal velocities obtained from H218O are higher than those from H216O with differences that evolve in time and reach about 150 m s−1 on average around perihelion. A discussion is provided on how to explain this peculiar behavior.
Published: 2021
Full Text: View/download PDF

9. Seasonal exposure of carbon dioxide ice on the nucleus of comet 67P/Churyumov-Gerasimenko

Author: Luigi Colangeli, Vito Mennella, Federico Tosi, M. Combes, D. Despan, Patrick G. J. Irwin, Andrea Cicchetti, Lydie Bonal, Bernard Schmitt, Nicolas Biver, M. Cartacci, Florence Henry, Th. Encrenaz, Romolo Politi, Michelangelo Formisano, M. A. Barucci, David Kappel, Eric Quirico, Mauro Ciarniello, Roberto Orosei, Ralf Jaumann, Andrea Longobardo, Katrin Stephan, E. Kuehrt, Fabrizio Capaccioni, Yves Langevin, Wing-Huen Ip, Gianrico Filacchione, Michael R. Combi, Gabriele Arnold, Ernesto Palomba, Giovanna Rinaldi, D. Tiphene, Y. Hello, Robert W. Carlson, Ulrich Schade, Gianfranco Magni, Alessandra Migliorini, G. P. Tozzi, Sonia Fornasier, J. Crovisier, Andrea Raponi, Pierre Beck, U. Fink, Pierre Drossart, Stefano Mottola, Enrico Flamini, M. C. De Sanctis, D. Bockelee-Morvan, Marcello Fulchignoni, Kathrin Markus, Giancarlo Bellucci, M. T. Capria, G. Peter, Davide Grassi, F. Merlin, Sergio Fonti, Costanzo Federico, Eleonora Ammannito, M. I. Blecka, Armando Blanco, Raffaella Noschese, Jean-Michel Reess, T. B. McCord, Alessandro Frigeri, C. Leyrat, Giuseppe Piccioni, Priscilla Cerroni, U. Carsenty, F. Mancarella, L. Moroz, Fredric W. Taylor, Jean-Pierre Bibring, Stéphane Erard, Johannes Benkhoff, S. Jacquinod, J. Ph. Combe, M. S. Gudipati, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Polska Akademia Nauk = Polish Academy of Sciences (PAN), German Aerospace Center (DLR), INAF - Osservatorio Astronomico di Capodimonte (OAC), Department of Physics [Imperial College London], Imperial College London, Instituto de Estudos Avançados (IEAV), Institut, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Dipartimento di Fisica, Università degli studi di Lecce, Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Department of Physics [Oxford], University of Oxford, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], INAF - Osservatorio Astrofisico di Arcetri (OAA), Laboratoire de Sciences de la Terre, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Alenia Aerospazio, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Department of Physics [Lecce], Università del Salento [Lecce], JDS Uniphase/Cronos, USA, JDS Uniphase/Cronos, IASI (IASI), Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), Consiglio Nazionale delle Ricerche (CNR), European Space Agency (ESA), University of Oxford [Oxford], Max-Planck-Institut für Sonnensystemforschung (MPS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), ITA, USA, GBR, FRA, DEU, TWN, and NLD
Subjects: [PHYS]Physics [physics], Multidisciplinary, 010504 meteorology & atmospheric sciences, Infrared, Atmospheric sciences, 01 natural sciences, Astrobiology, chemistry.chemical_compound, medicine.anatomical_structure, chemistry, 13. Climate action, Comet nucleus, Rosetta, 0103 physical sciences, Carbon dioxide, medicine, Environmental science, Surface layer, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Nucleus, Volatility (chemistry), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Rosetta observes sublimating surface icesComets are “dirty snowballs” made of ice and dust, but they are dark because the ice sublimates away, leaving some of the dust behind on the surface. The Rosetta spacecraft has provided a close-up view of the comet 67P/Churyumov-Gerasimenko as it passes through its closest point to the Sun (see the Perspective by Dello Russo). Filacchioneet al.detected the spectral signature of solid CO2(dry ice) in small patches on the surface of the nucleus as they emerged from local winter. By modeling how the CO2sublimates, they constrain the composition of comets and how ices generate the gaseous coma and tail. Fornasieret al.studied images of the comet and discovered bright patches on the surface where ice was exposed, which disappeared as the ice sublimated. They also saw frost emerging from receding shadows. The surface of the comet was noticeably less red just after local dawn, indicating that icy material is removed by sunlight during the local day.Science, this issue p.1563, p.1566; see also p.1536
Published: 2016
Full Text: View/download PDF

10. ALMA Autocorrelation Spectroscopy of Comets: The HCN/H 13 CN Ratio in C/2012 S1 (ISON)

Author: M. Y. Palmer, Dariusz C. Lis, Steven B. Charnley, Stefanie N. Milam, Martin A. Cordiner, Geronimo Villanueva, N. Biver, J. Crovisier, Lucas Paganini, M. J. Mumma, Yi-Jehng Kuan, Dominique Bockelée-Morvan, Anthony J. Remijan, M. de Val-Borro, Departament d'Astronomia i Meteorologia [Barcelona] (DAM), Universitat de Barcelona (UB), NASA Goddard Space Flight Center (GSFC), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), National Radio Astronomy Observatory (NRAO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], Physics, Astrochemistry, 010504 meteorology & atmospheric sciences, Autocorrelation, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Space and Planetary Science, 0103 physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Spectroscopy, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: The Atacama Large Millimeter/submillimeter Array (ALMA) is a powerful tool for high-resolution mapping of comets, but the main interferometer (comprised of 50x12-m antennas) is insensitive to the largest coma scales due to a lack of very short baselines. In this work, we present a new technique employing ALMA autocorrelation data (obtained simultaneously with the interferometric observations), effectively treating the entire 12-m array as a collection of single-dish telescopes. Using combined autocorrelation spectra from 28 active antennas, we recovered extended HCN coma emission from comet C/2012 S1 (ISON), resulting in a fourteen-fold increase in detected line brightness compared with the interferometer. This resulted in the first detection of rotational emission from H^13CN in this comet. Using a detailed coma radiative transfer model accounting for optical depth and non-LTE excitation effects, we obtained an H^12CN/H^13CN ratio of 88+-18, which matches the terrestrial value of 89, consistent with a lack of isotopic fractionation in HCN during comet formation in the protosolar accretion disk. The possibility of future discoveries in extended sources using autocorrelation spectroscopy from the main ALMA array is thus demonstrated.
Published: 2019
Full Text: View/download PDF

11. VIRTIS-H observations of the dust coma of comet 67P/Churyumov-Gerasimenko: spectral properties and color temperature variability with phase and elevation

Author: Stéphane Erard, Pierre Drossart, Mauro Ciarniello, Gabriele Arnold, M. T. Capria, David Kappel, Giovanna Rinaldi, Andrea Longobardo, F. Andrieu, Fabrizio Capaccioni, J. Crovisier, Fredric W. Taylor, Pedro Hasselmann, M. C. De Sanctis, Dominique Bockelée-Morvan, C. Leyrat, Gianrico Filacchione, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), DLR Institut für Planetenforschung, University of Oxford [Oxford], and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Asteroiden und Kometen, 010504 meteorology & atmospheric sciences, Comet, Coma (optics), Astrophysics, Color temperature, 01 natural sciences, comets: individual: 67P, Phase (matter), 0103 physical sciences, infrared: planetary systems, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Churyumov-Gerasimenko, Physics, [PHYS]Physics [physics], comets: general, Spectral properties, Leitungsbereich PF, Elevation, comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, 13. Climate action, Space and Planetary Science, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: We analyze 2–5μm spectroscopic observations of the dust coma of comet 67P/Churyumov-Gerasimenko obtained with the Visible InfraRed Thermal Imaging Spectrometer (VIRTIS-H) instrument on board Rosetta from 3 June to 29 October 2015 at heliocentric distancesrh= 1.24–1.55 AU. The 2–2.5μm color, bolometric albedo, and color temperature were measured using spectral fitting. Data obtained atα= 90° solar phase angle show an increase in bolometric albedo (0.05–0.14) with increasing altitude (0.5–8 km), accompanied by a possible marginal decrease in color and color temperature. Possible explanations include dark particles on ballistic trajectories in the inner coma and radial changes in particle composition. In the phase angle range 50°–120°, phase reddening is significant (0.031%/100 nm deg−1) for a mean color of 2%/100 nm atα= 90°, which might be related to the roughness of the dust particles. Moreover, a decrease in color temperature with decreasing phase angle is also observed at a rate of ~0.3 K deg−1, consistent with the presence of large porous particles, with low thermal inertia, and showing a significant day-to-night temperature contrast. Comparing data acquired at fixed phase angle (α= 90°), a 20% increase in bolometric albedo is observed near perihelion. Heliocentric variations in dust color are not significant in the time period we analyzed. The measured color temperatures vary from 260 to 320 K, and follow arh−0.6variation in therh= 1.24–1.5 AU range, which is close to the expectedrh−0.5value.
Published: 2019
Full Text: View/download PDF

12. Erratum: Comet 67P outbursts and quiescent coma at 1.3 au from the Sun: dust properties from Rosetta/VIRTIS-H observations

Author: Dominique Bockelée-Morvan, G Rinaldi, S Erard, C Leyrat, F Capaccioni, P Drossart, G Filacchione, A Migliorini, E Quirico, S Mottola, G Tozzi, G Arnold, N Biver, M Combes, J Crovisier, A Longobardo, M Blecka, M-T Capria, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), IASI (IASI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Istituto Fisica Spazio Interplanetario, Dysoxie, suractivité : aspects cellulaires et intégratifs thérapeutiques (DS-ACI / UMR MD2), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Consiglio Nazionale delle Ricerche (CNR), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), and bibliotheque, la.
Subjects: [PHYS]Physics [physics], Asteroiden und Kometen, 010504 meteorology & atmospheric sciences, comets: general, Leitungsbereich PF, comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, [PHYS] Physics [physics], 13. Climate action, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], infrared: planetary systems, 010303 astronomy & astrophysics, addenda, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, errata, 0105 earth and related environmental sciences
Abstract: The paper 'Comet 67P outbursts and quiescent coma at 1.3 AU from the Sun: dust properties from Rosetta/VIRTIS-H observations' was published in MNRAS 469, S443 (2017). While performing a follow-up investigation, we discovered a numerical error in the algorithms that were developed to model the infrared continuum emission from a population of dust particles. The results of the scattering models for compact or moderately porous grains (Mie theory) and fluffy grains (Rayleigh-Gans-Debye theory, RGD) are both affected. Though the general conclusions of the paper are unchanged, the quantitative constraints obtained on the dust size distribution in the quiescent coma are slightly different.
Published: 2018
Full Text: View/download PDF

13. Thermal Physics of the Inner Coma: ALMA Studies of the Methanol Distribution and Excitation in Comet C/2012 K1 (PanSTARRS)

Author: Nicolas Biver, Yi-Jehng Kuan, Anthony J. Remijan, Geronimo L. Villanueva, Martin A. Cordiner, Jérémie Boissier, J. Crovisier, Dariusz C. Lis, Dominique Bockelée-Morvan, Steven B. Charnley, Lucas Paganini, Iain Coulson, M. J. Mumma, Stefanie N. Milam, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), NASA Goddard Space Flight Center (GSFC), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris), Biologie et écologie tropicale et méditerranéenne [2007-2010] (BETM), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, Mean kinetic temperature, Radiative cooling, Comet, FOS: Physical sciences, Astronomy and Astrophysics, Rotational temperature, Coma (optics), Astrophysics, 01 natural sciences, Submillimeter Array, Space and Planetary Science, 0103 physical sciences, Millimeter, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Excitation, ComputingMilieux_MISCELLANEOUS, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: We present spatially and spectrally-resolved observations of CH$_3$OH emission from comet C/2012 K1 (PanSTARRS) using The Atacama Large Millimeter/submillimeter Array (ALMA) on 2014 June 28-29. Two-dimensional maps of the line-of-sight average rotational temperature ($T_{rot}$) were derived, covering spatial scales $0.3''-1.8''$ (corresponding to sky-projected distances $\rho\sim500$-2500 km). The CH$_3$OH column density distributions are consistent with isotropic, uniform outflow from the nucleus, with no evidence for extended sources of CH$_3$OH in the coma. The $T_{rot}(\rho)$ radial profiles show a significant drop within a few thousand kilometers of the nucleus, falling from about 60 K to 20 K between $\rho=0$ and 2500 km on June 28, whereas on June 29, $T_{rot}$ fell from about 120 K to 40 K between $\rho=$ 0 km and 1000 km. The observed $T_{rot}$ behavior is interpreted primarily as a result of variations in the coma kinetic temperature due to adiabatic cooling of the outflowing gas, as well as radiative cooling of the CH$_3$OH rotational levels. Our excitation model shows that radiative cooling is more important for the $J=7-6$ transitions (at 338 GHz) than for the $K=3-2$ transitions (at 252 GHz), resulting in a strongly sub-thermal distribution of levels in the $J=7-6$ band at $\rho\gtrsim1000$ km. For both bands, the observed temperature drop with distance is less steep than predicted by standard coma theoretical models, which suggests the presence of a significant source of heating in addition to the photolytic heat sources usually considered., Comment: Accepted for publication in ApJ, January 2017
Published: 2017
Full Text: View/download PDF

14. The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta

Author: Gabriele Arnold, Maria Teresa Capria, Y. Hello, Kathrin Markus, Vincenzo Orofino, A. Semery, Romolo Politi, Stéphane Erard, Roberto Orosei, Robert W. Carlson, Davide Grassi, M. Combes, J. Crovisier, Gianfranco Magni, Andrea Raponi, Michael R. Combi, Priscilla Cerroni, Yves Langevin, L. Moroz, Pierre Drossart, Ulrich Schade, G. P. Tozzi, Wing-Huen Ip, Luigi Colangeli, Fredric W. Taylor, Angioletta Coradini, J. Ph. Combe, Raffaella Noschese, Enrico Flamini, Giancarlo Bellucci, Ernesto Palomba, Sonia Fornasier, F. Merlin, Lydie Bonal, Andrea Longobardo, G. Peter, M. Cartacci, Alessandro Frigeri, Giuseppe Piccioni, Bernard Schmitt, Uwe Fink, Ralf Jaumann, Mauro Ciarniello, D. Despan, M. A. Barucci, Giovanna Rinaldi, Pierre Beck, M. C. De Sanctis, S. Giuppi, S. Jacquinod, Uri Carsenty, D. Bockelee-Morvan, Eric Quirico, Stefano Mottola, F. Henry, N. Biver, Jean-Pierre Bibring, Patrick G. J. Irwin, T. Encrenaz, Katrin Stephan, Andrea Cicchetti, Johannes Benkhoff, C. Leyrat, Gianrico Filacchione, D. Tiphene, J. M. Reess, T. B. McCord, Sergio Fonti, Costanzo Federico, Eleonora Ammannito, M. I. Blecka, Pasquale Palumbo, Armando Blanco, M. Gudipati, Fabrizio Capaccioni, Vito Mennella, Federico Tosi, E. Kuehrt, F., Capaccioni, A., Coradini, G., Filacchione, S., Erard, G., Arnold, P., Drossart, M. C., De Sancti, D., Bockelee Morvan, M. T., Capria, F., Tosi, C., Leyrat, B., Schmitt, E., Quirico, P., Cerroni, V., Mennella, A., Raponi, M., Ciarniello, T., Mccord, L., Moroz, E., Palomba, E., Ammannito, M. A., Barucci, G., Bellucci, J., Benkhoff, J. P., Bibring, Blanco, Armando, M., Blecka, R., Carlson, U., Carsenty, L., Colangeli, M., Combe, M., Combi, J., Crovisier, T., Encrenaz, C., Federico, U., Fink, Fonti, Sergio, W. H., Ip, P., Irwin, R., Jaumann, E., Kuehrt, Y., Langevin, G., Magni, S., Mottola, Orofino, Vincenzo, P., Palumbo, G., Piccioni, U., Schade, F., Taylor, D., Tiphene, G. P., Tozzi, P., Beck, N., Biver, L., Bonal, Combe, J. P. h., D., Despan, E., Flamini, S., Fornasier, A., Frigeri, D., Grassi, M., Gudipati, A., Longobardo, K., Marku, F., Merlin, R., Orosei, G., Rinaldi, K., Stephan, M., Cartacci, A., Cicchetti, S., Giuppi, Y., Hello, F., Henry, S., Jacquinod, R., Noschese, G., Peter, R., Politi, J. M., Ree, A., Semery, Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Polska Akademia Nauk (PAN), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, German Aerospace Center (DLR), Department of Physics [Imperial College London], Imperial College London, Instituto de Estudos Avançados (IEAV), Institut, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Dipartimento di Fisica, Università degli studi di Lecce, Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], DLR Institute of Planetary Research, Department of Physics [Lecce], Università del Salento [Lecce], INAF - Osservatorio Astrofisico di Arcetri (OAA), Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Alenia Aerospazio, JDS Uniphase/Cronos, USA, JDS Uniphase/Cronos, CNR-IASF, IASI (IASI), Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Polska Akademia Nauk = Polish Academy of Sciences (PAN), NASA-California Institute of Technology (CALTECH), University of Oxford, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), ITA, USA, GBR, FRA, DEU, TWN, NLD, and POL
Subjects: 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Opacity, Rosetta mission, VIRTIS, comets, Infrared, Comet, Imaging spectrometer, Astrophysics, 01 natural sciences, Astrobiology, comet, 0103 physical sciences, Spectral slope, Thermal, Rosetta, Rosetta mission, comets, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Multidisciplinary, Chemistry, Albedo, VIRTIS, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], organic-rich
Abstract: The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared ranges (5 to 25 and 1.5 to 5% kÅ −1 ), and the broad absorption feature in the 2.9-to-3.6–micrometer range present across the entire illuminated surface are compatible with opaque minerals associated with nonvolatile organic macromolecular materials: a complex mixture of various types of carbon-hydrogen and/or oxygen-hydrogen chemical groups, with little contribution of nitrogen-hydrogen groups. In active areas, the changes in spectral slope and absorption feature width may suggest small amounts of water-ice. However, no ice-rich patches are observed, indicating a generally dehydrated nature for the surface currently illuminated by the Sun.
Published: 2015
Full Text: View/download PDF

15. Present and Future Cometary Science with the IRAM Plateau de Bure Interferometer

Author: J. Crovisier, N. Biver, Emmanuel Lellouch, Dominique Bockelée-Morvan, R. Moreno, Jérémie Boissier, R. Neri, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Physics, geography, Plateau, geography.geographical_feature_category, Comet, Continuum (design consultancy), Northern Hemisphere, Plateau de Bure Interferometer, Astronomy, Astronomy and Astrophysics, Outgassing, Interferometry, Planetary science, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience; Interferometric observations are essential to probe the molecular emission in the inner cometary atmospheres and study the outgassing from the nucleus. Mapping the continuum emission can provide information about the dust and/or nucleus properties. We present here a summary of the observations of the dust and gas coma of comet 17P/Holmes and nuclear observations of 8P/Tuttle, both carried out with the IRAM interferometer at Plateau de Bure (PdBI) in 2007-2008. The observations of these two comets demonstrate the ability of the PdBI in terms of cometary science. In the near future, several improvements will be made (new receivers at 0.8 mm, a new wide-band correlator) allowing more frequent and more detailed studies of comets. On the long term, NOEMA, an expansion project, may add up to six antennas to the Plateau de Bure Interferometer, and increase the baseline lengths. Such an instrument would offer a complement to ALMA to track comets of the northern hemisphere with about half the sensitivity of ALMA for continuum studies.
Published: 2009
Full Text: View/download PDF

16. Production and kinematics of CO in comet C/1995 O1 (Hale-Bopp) at large post-perihelion distances

Author: F. Rantakyrö, Florence Henry, John K. Davies, N. Biver, P. Colom, J. Crovisier, L. E. B. Johansson, Dominique Bockelée-Morvan, R. Moreno, Didier Despois, M. Gunnarsson, Hans Rickman, Gabriel Paubert, Anders Winnberg, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Physics, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Comet, Astronomy, Astronomy and Astrophysics, Kinematics, Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrobiology
Abstract: Production and Kinematics of CO in Comet 1995 O1 (Hale-Bopp) at Large Post-Perihelion Distances
Published: 2003
Full Text: View/download PDF

17. Titan's 5-μm window: observations with the Very Large Telescope

Author: J. G. Cuby, E. Lellouch, B. Sebag, Bernard Schmitt, A. Coustenis, Thierry Fouchet, Miguel Lopez-Valverde, J. Crovisier, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Physics, Very Large Telescope, Astronomy, Astronomy and Astrophysics, Astrophysics, Atmosphere, Troposphere, symbols.namesake, Space and Planetary Science, Geometric albedo, symbols, Mixing ratio, Emission spectrum, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Titan (rocket family), Stratosphere
Abstract: We report on mid-resolution ( R ∼2000) spectroscopic observations of Titan, acquired in November 2000 with the Very Large Telescope and covering the range 4.75–5.07 μm. These observations provide a detailed characterization of the CO (1–0) vibrational band, clearly separating for the first time individual CO lines (P10 to P19 lines of 13 CO). They indicate that the CO/N 2 mixing ratio in Titan’s troposphere is 32±10 ppm. Comparison with photochemical models indicates that CO is not in a steady state in Titan’s atmosphere. The observations confirm that Titan’s 5-μm continuum geometric albedo is ∼0.06, and further indicates a ∼20% albedo decrease over 4.98–5.07 μm. Nonzero flux is detected at the 0.01 geometric albedo level in the saturated core of the 12 CO (1–0) band, at 4.75–4.85 μm, providing evidence for backscattering on the stratospheric haze. Finally, emission lines are detected at 4.75–4.835 μm, coinciding in position with lines from the CO(1–0) and/or CO(2–1) bands. Matching them by thermal emission would require Titan’s stratosphere to be much warmer (by ∼ 25 K at 0.1 mbar) than indicated by the methane 7.7-μm emission and the Voyager radio-occultation. We show instead that a nonthermal mechanism, namely solar-excited fluorescence, is a more plausible source for these emissions. Improved observations and laboratory measurements on the vibrational–translational relaxation of CO are needed for further interpretation of these emissions in terms of a CO stratospheric mixing ratio.
Published: 2003
Full Text: View/download PDF

18. Cometary science. The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta

Author: F, Capaccioni, A, Coradini, G, Filacchione, S, Erard, G, Arnold, P, Drossart, M C, De Sanctis, D, Bockelee-Morvan, M T, Capria, F, Tosi, C, Leyrat, B, Schmitt, E, Quirico, P, Cerroni, V, Mennella, A, Raponi, M, Ciarniello, T, McCord, L, Moroz, E, Palomba, E, Ammannito, M A, Barucci, G, Bellucci, J, Benkhoff, J P, Bibring, A, Blanco, M, Blecka, R, Carlson, U, Carsenty, L, Colangeli, M, Combes, M, Combi, J, Crovisier, T, Encrenaz, C, Federico, U, Fink, S, Fonti, W H, Ip, P, Irwin, R, Jaumann, E, Kuehrt, Y, Langevin, G, Magni, S, Mottola, V, Orofino, P, Palumbo, G, Piccioni, U, Schade, F, Taylor, D, Tiphene, G P, Tozzi, P, Beck, N, Biver, L, Bonal, J-Ph, Combe, D, Despan, E, Flamini, S, Fornasier, A, Frigeri, D, Grassi, M, Gudipati, A, Longobardo, K, Markus, F, Merlin, R, Orosei, G, Rinaldi, K, Stephan, M, Cartacci, A, Cicchetti, S, Giuppi, Y, Hello, F, Henry, S, Jacquinod, R, Noschese, G, Peter, R, Politi, J M, Reess, and A, Semery
Abstract: The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared ranges (5 to 25 and 1.5 to 5% kÅ(-1)), and the broad absorption feature in the 2.9-to-3.6-micrometer range present across the entire illuminated surface are compatible with opaque minerals associated with nonvolatile organic macromolecular materials: a complex mixture of various types of carbon-hydrogen and/or oxygen-hydrogen chemical groups, with little contribution of nitrogen-hydrogen groups. In active areas, the changes in spectral slope and absorption feature width may suggest small amounts of water-ice. However, no ice-rich patches are observed, indicating a generally dehydrated nature for the surface currently illuminated by the Sun.
Published: 2015

19. Observations at Nançay of the OH 18-cm lines in comets

Author: J. Crovisier, E. Gérard, P. Colom, Dominique Bockelée-Morvan, G. Bourgois, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Physics, Zeeman effect, Comet, Astronomy, Astronomy and Astrophysics, Astrophysics, Water production, law.invention, Radio telescope, Telescope, symbols.namesake, [SDU]Sciences of the Universe [physics], Space and Planetary Science, law, symbols, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Since the apparition of comet Kohoutek 1973 XII, the 18-cm lines of the OH radical have been systematically observed in a number of comets with the Nancay radio telescope. Between 1973 and 1999, 52 comets have been successfully detected. This allowed an evaluation of the cometary water production rates and their evolution with time, as well as a study of several physical processes such as the excitation mechanisms of the OH radio lines, the expansion of cometary atmospheres, their anisotropy in relation to non-gravitational forces, and the Zeeman effect in relation to the cometary magnetic field. Part of these observations and their analysis have already been published. The bulk of the results are now organized in a data base. The present paper is a general presentation of the Nancay cometary data base and a more specific description of the observations of 53 cometary apparitions between 1982 and 1999. Comets observed before 1982 are only partly incorporated in the data base. Observations of comets since 2000 have benefited from a major upgrade of the telescope; they will be presented in forthcoming publications.
Published: 2002
Full Text: View/download PDF

20. The volatile composition of 81P/Wild 2 from ground-based high-resolution infrared spectroscopy

Author: Anita L. Cochran, N. Biver, Dominique Bockelée-Morvan, Ronald J. Vervack, Hideyo Kawakita, Harold A. Weaver, Hitomi Kobayashi, Walter M. Harris, J. Crovisier, N. Dello Russo, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, Chemistry, Comet, Analytical chemistry, High resolution, Infrared spectroscopy, Astronomy and Astrophysics, Small sample, Astrophysics, Spatial distribution, 01 natural sciences, 13. Climate action, Space and Planetary Science, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Volatile abundances in Jupiter-family Comet 81P/Wild 2 were measured on four dates in February and March 2010 using high-dispersion ( λ Δ λ ∼ 2.5 × 10 4 ) infrared spectroscopy with NIRSPEC at the W.M. Keck Observatory. H 2 O was detected on all dates, including measurements on UT March 29 of lines from the ν 2 + ν 3 − ν 2 hot-band not previously targeted in comets. C 2 H 6 and HCN were detected on three dates, and CH 3 OH was detected on one date. Tentative detections or upper-limits are reported for CH 3 OH on other dates, as well as for C 2 H 2 , H 2 CO, and NH 3 . Abundances of all species relative to H 2 O are in the typical range with the exception of CH 3 OH, which is depleted compared to other comets. Gas production was significantly higher in late February than in late March. Rotational temperatures were determined for H 2 O on UT February 22 and 23 and found to be about 30–40 K. The spatial distributions of H 2 O, C 2 H 6 , and CH 3 OH are all symmetric and similar to the spatial distribution of the dust continuum. H 2 O abundances from this work are compared to other measurements from both the 1997 and 2010 apparitions. There is no clear evidence of a change in overall gas productivity between the two apparitions within measurement accuracy. Abundances of C 2 H 2 , C 2 H 6 , HCN and NH 3 are consistent with these species being the primary parents of C 2 , CN, NH and NH 2 as measured at optical wavelengths. Although optically classified as carbon-chain depleted, Wild 2 appears more chemically similar in parent volatile chemistry to carbon-chain typical comets; however, we note that in the small sample of Jupiter-family comets measured to date, each comet is chemically distinct.
Published: 2014
Full Text: View/download PDF

21. Herschel observations of gas and dust in comet C/2006 W3 (Christensen) at 5 AU from the Sun

Author: Miriam Rengel, Jean Manfroid, C. Waelkens, Emmanuel Jehin, D. Teyssier, Th. de Graauw, L. M. Lara, Christopher Jarchow, Paul Hartogh, Ladislav Rezac, Michael Küppers, Dominique Bockelée-Morvan, Damien Hutsemekers, M. de Val-Borro, M. R. Kidger, C. Opitom, Slawomira Szutowicz, Dariusz C. Lis, N. Biver, B. M. Swinyard, B. Vandenbussche, J. Crovisier, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Max Planck Institute for Aeronomy (MPAe), foreign laboratories (FL), CERN [Genève], Instituto de Astrofisica de Canarias (IAC), Department of Physiology and Biochemistry of Animal Nutrition, Spanish National Research Council (CSIC), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), and Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], Subsolar point, individual: C/2006 W3 (Christensen) [comets], FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Thermal emission, planetary systems [submillimeter], Spectral line, Blueshift, photometric [techniques], Outgassing, 13. Climate action, Space and Planetary Science, Sublimation (phase transition), spectroscopic [techniques], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Hyperfine structure, Order of magnitude, ComputingMilieux_MISCELLANEOUS, Astrophysics - Earth and Planetary Astrophysics
Abstract: We aimed to measure the H2O and dust production rates in C/2006 W3 (Christensen) with the Herschel Space Observatory at a heliocentric distance of ~ 5 AU. We have searched for emission in the H2O and NH3 ground-state rotational transitions at 557 GHz and 572 GHz, simultaneously, with HIFI onboard Herschel on UT 1.5 September 2010. Photometric observations of the dust coma in the 70 and 160 {\mu}m channels were acquired with the PACS instrument on UT 26.5 August 2010. A tentative 4-{\sigma} H2O line emission feature was found in the spectra obtained with the HIFI wide-band and high-resolution spectrometers, from which we derive a water production rate of $2.0(5) \times 10^{27}$ molec. s$^{-1}$. A 3-{\sigma} upper limit for the ammonia production rate of, Comment: 13 pages, 9 figures
Published: 2014
Full Text: View/download PDF

22. Broadband infrared photometry of comet Hale-Bopp with ISOPHOT

Author: S. B. Peschke, Humberto Campins, T. Y. Brooke, Manfred Stickel, Eberhard Grün, H. U. Keller, J. Crovisier, M. Solc, V. Vanysek, John C. Zarnecki, David J. Osip, Mark V. Sykes, R. F. Knacke, Dietrich Lemke, Carey M. Lisse, Michael Müller, I. Heinrichsen, Philippe Lamy, Ch. Leinert, Harald Krüger, H. Boehnhardt, Martha S. Hanner, T. G. Muller, and C. Delahodde
Subjects: Physics, Brightness, Photometry (astronomy), Zodiacal light, Space and Planetary Science, Infrared, Comet, Astronomy, Spectral energy distribution, Astronomy and Astrophysics, Astrophysics, Spectral line, Comet Hale–Bopp
Abstract: Comet Hale-Bopp was observed five times with ISOPHOT, the photometer on board ESA's Infrared Space Observatory (ISO) between 4.6 and 2.8 AU. Each time, broadband photometry was performed using 4 different detectors, 5 apertures and 10 filters covering the range between 3.6 and 170 μm. Background observations were performed with identical instrument settings at the same positions on the sky several days after the comet observations. The observation strategy and the data reduction steps are described in some detail, including the techniques to correct for variable detector responsivity. The resulting inband power values of the Hale-Bopp observations and their uncertainties are given. The mean uncertainty is 25%. The final fluxes were computed, taking into account the zodiacal background, possible offset of the comet's position from the center of the aperture, the brightness distribution within the coma, and the spectral energy distribution of the comet's emission. Strong thermal emission from a broad size distribution of dust particles was detected in all of the data sets, even at r = 4.6-4.9 AU pre-perihelion and 3.9 AU post-perihelion; the total thermal energy varied as r-3. The 7.3-12.8 μm color temperature was ~1.5 times the blackbody temperature, higher than that observed in any other comet. Silicate features at 10 and 25 μm were prominent in all 5 data sets, the largest heliocentric distances that silicate emission has been detected in a comet. The presence of crystalline water ice grains is suggested from the 60 μm excess emission at 4.6-4.9 AU, consistent with the observed QOH if the icy grains were slightly warmer than an equilibrium blackbody. The average albedo of the dust is higher than that of comet P/Halley, but lower than other albedo measurements for Hale-Bopp nearer perihelion. There is no evidence for a component of cold, bright icy grains enhancing the scattered light at 4.6 AU. Simple models for a mixture of silicate and absorbing grains were fit to the ISO spectra and photometry at 2.8 AU. The observed flux at λ >100 μm requires a size distribution in which most of the mass is concentrated in large particles. Dust production rates of order 1.5 x 105 kg s-1 at 2.8 AU and 3 x 104 kg s-1 at 4.6 AU have been found. They correspond to dust to gas mass ratios of 6 to 10.
Published: 2001
Full Text: View/download PDF

23. The Mars flyby of ROSETTA: an opportunity for infrared and microwave high-resolution sounding

Author: Yves Langevin, E. Lellouch, Stéphane Erard, B. Germain, J. Crovisier, Th. Encrenaz, Samuel Gulkis, Pierre Drossart, Angioletta Coradini, and Gerard Beaudin
Subjects: Photometry (optics), Depth sounding, Spectrometer, Space and Planetary Science, Orbit of Mars, Imaging spectrometer, Radiometry, Environmental science, Astronomy and Astrophysics, Atmosphere of Mars, Mars Exploration Program, Remote sensing, Astrobiology
Abstract: The Mars #yby of ROSETTA will provide a valuable opportunity for sounding, at high spatial resolution, the Mars atmosphere and surface in the infrared and microwave range. The VIRTIS infrared imaging spectrometer should be able to determine the surface mineralogy and temperature of the observed areas, the abundances of minor constituents (H2O, CO), and possibly to study the atmospheric thermal pro?le. VIRTIS will complement the OMEGA and PFS infrared spectrometers on-board the Mars Express mission, expected to operate in Mars orbit at the time of the ROSETTA #yby. The MIRO microwave spectrometer is expected to provide information on the thermal pro?le, the H 2O vertical distribution, the temperature of the subsurface, and possibly the atmospheric winds. In addition, the Mars #yby of ROSETTA will provide the ?rst opportunity for testing the VIRTIS and MIRO instruments, in particular for wavelength =frequency and photometry=radiometry calibration. c
Published: 2001
Full Text: View/download PDF

24. The 2.4– spectrum of Mars observed with the infrared space observatory

Author: Helmut Feuchtgruber, J. Crovisier, Patrick W. Morris, E. Lellouch, T Girard, M. Burgdorf, T. de Graauw, Stéphane Erard, and T. Encrenaz
Subjects: Materials science, Spectrometer, business.industry, Infrared, Planetary Fourier Spectrometer, Analytical chemistry, Astronomy and Astrophysics, Atmosphere of Mars, Mars Exploration Program, Palagonite, Optics, Space and Planetary Science, business, Spectroscopy, Absorption (electromagnetic radiation)
Abstract: The spectrum of Mars at 2.4-45 mum has been observed on July 31, 1997 (L-s = 157 degrees) by the Short-Wavelength Spectrometer of the Infrared Space Observatory. The data consist of a high signal to noise, complete grating spectrum (resolving power R similar to 1500-2500) and portions of the 20-45 mum spectrum observed in Fabry-Perot mode (R similar to 31000). The data show the infrared bands of known martian atmospheric species (CO2, H2O, and CO) with an unprecedented amount of details. The vertical distribution of H2(O) is determined, showing saturation near 10 km. Evidence for scattering in the saturated CO2 band at 2.7 mum and for fluorescence emission in the CO2 4.3 pm band is obtained. No detection of new atmospheric species is achieved, but upper limits are obtained for CH4 and H2CO. In the solar reflected part of the spectrum, which dominates at lambda less than or equal to 4.2 mum, the surface reflectance clearly shows the hydration band with maximum absorption at 2.9 mum, from which a 2.0 -2.7% (by weight) water content in the martian uppermost layer is estimated. A decrease of reflectance from 3.8 to 5 mum is also seen. This behaviour is consistent with basalts and palagonite, but not hematite. Ln the thermal part, mineralogic signatures at 5-12 mum are globally consistent with a basaltic composition. Specific minima an also detected at 5.7, 6.3 (tentative), 7.2 and 11.1 mum. Reexamination of earlier datasets indicates that the latter two have been observed before, although generally not discussed. The presence of additional absorptions at 26.5, 31 and 33.5 mum is also indirectly suggested. Carbonate minerals are tentatively detected from this ensemble of features, though no single carbonate species can be unambiguously identified. (C) 2000 Elsevier Science Ltd. All rights reserved.
Published: 2000
Full Text: View/download PDF

25. Observations of Gas and Dust in Comets with the Infrared Space Observatory

Author: J. Crovisier
Subjects: Physics, Infrared astronomy, Olivine, 010504 meteorology & atmospheric sciences, Infrared, Comet, Astronomy, Astrophysics, Forsterite, Far-infrared astronomy, engineering.material, 01 natural sciences, Spectral line, Cosmic infrared background, 0103 physical sciences, engineering, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: The Infrared Space Observatory (ISO) offered us the opportunity to observe celestial bodies from 2.4 to 196 μm, which is of particular interest for comets. We present here spectroscopic observations with ISO of comets C/1995 O1 (Hale-Bopp) and 103P/Hartley 2. Fluorescence emissions of H2O, CO2 and (for comet Hale-Bopp only) CO and CH4 are observed, yielding the production rates of these species. High-resolution spectra of water permit the study of the rotational and spin temperatures of this molecule. In comet Hale-Bopp, the thermal infrared region of the spectra shows specifically, in addition to continuum-like emission, the signatures of crystalline, Mg-rich olivine (forsterite), and signs of crystalline pyroxenes, amorphous silicates and water ice. The presence of crystalline silicates is also suggested in the Jupiter-family comet P/Hartley 2.
Published: 2000
Full Text: View/download PDF

26. Physics and chemistry of comets: recent results from comets Hyakutake and Hale–Bopp Answers to old questions and new enigmas

Author: J. Crovisier
Subjects: Physics, Comet nucleus, Comet dust, Interstellar comet, Comet, Astronomical unit, Astronomy, Physical and Theoretical Chemistry, Astrobiology
Abstract: 1996 and 1997 years were very prolific years for cometary studies. In March 1996, C/1996 B2 (Hyakutake), a medium-bright comet, passed at only 0.10 astronomical units (AU) from the Earth. On 1st April, 1997, C/1995 O1 (Hale–Bopp) passed at perihelion. This comet was 10 to 100 times brighter than comet Halley when compared at the same distance. It could be studied and monitored from its discovery in July 1995 as far as 7 AU from the Sun until its perihelion at 0.9 AU, where it was the object of extensive observations. It was thus possible to study these two exceptional comets with modern instrumentation covering the electromagnetic spectrum from radio to X-ray domains. Our knowledge of the composition and nature of comets has been transformed. New cometary molecules were observed, as well as isotopic species. New physical processes could be studied, owing to the large amounts of matter escaping from these objects, to the proximity of Earth allowing a detailed investigation of the region close to the nucleus (comet Hyakutake), or to the unusual physical conditions far from the Sun (comet Hale–Bopp). Selected results of these observations, relevant to the chemistry and physics of molecules and grains, are discussed. It is shown that whereas some old problems are now solved, new ones have emerged. The needs for laboratory data and theoretical work are pointed out.
Published: 1998
Full Text: View/download PDF

27. [Untitled]

Author: Heike Rauer, Nicolas Biver, J. Crovisier, D. Bockelé-Morvan, E. Gerard, and P. Colom
Subjects: Physics, Radio telescope, Space and Planetary Science, Comet, Earth and Planetary Sciences (miscellaneous), Astronomy, Astronomy and Astrophysics, Astrophysics, Production rate, Radio astronomy
Abstract: We present OH 18-cm observations of comet Hale-Bopp (C/1995 O1) at the Nancay radio telescope. On nucleus and offset position observations allowed us to obtain both OH production rates and quenching radii. The maximum OH production rate was reached around perihelion, at about1031 s-1.
Published: 1997
Full Text: View/download PDF

28. Detectability of molecular species in planetary and satellite atmospheres from their rotational transitions

Author: Sushil K. Atreya, Bruno Bézard, E. Lellouch, Th. Encrenaz, A. Coustenis, Samuel Gulkis, and J. Crovisier
Subjects: Physics, biology, Astronomy, Astronomy and Astrophysics, Venus, Mars Exploration Program, biology.organism_classification, Space exploration, Spectral line, Pluto, Atmosphere, symbols.namesake, Space and Planetary Science, Planet, symbols, Titan (rocket family)
Abstract: High-resolution spectroscopy in the millimeter and submillimeter range has made significant contributions to the study of chemical composition and thermal structure of planetary and satellite atmospheres. This field of research is expected to make considerable progress in the future, from both ground-based and space experiments, with the availability of heterodyne receivers at frequencies up to 1 THz, and with the development of space missions devoted to the exploration of the far-infrared and submillimeter range. A compilation of guidelines for searching molecular species in planetary atmospheres through their rotational transitions, from the millimeter to the far-infrared range (100 μm) is presented. These transitions are specified, and the corresponding synthetic spectra are shown, or detectability limits are estimated. Several observational scenarios are considered: (1) ground-based heterodyne observations (such as those with IRAM, CSO, JCMT); (2) space heterodyne observations with a 3 m antenna (such as that on the European FIRST space mission); (3) Fabry-Perot spectroscopic observations from the ground and from space (such as the ISO and FIRST space missions). All planets (except Mercury) and the three satellites surrounded by an atmosphere, Titan, Triton and Io, are considered. The main results of this compilation can be summarized as follows. In addition to previously detected molecules, several species appear as promising candidates for detection in the far-infrared to millimeter spectral range. For ground-based heterodyne observations, they include: HCl, O 3 and SO on Venus; HCl, O 3 , H 2 O 2 and NO on Mars; HCl in the giant planets; SO on Io. For space observations, they are: O 2 on Venus and Mars (provided Venus is observable with FIRST), H 2 O in Saturn and Titan (with ISO and FIRST); HD, HCl and other halides in the giant planets (ISO). In the case of heterodyne observations, detectability limits are also indicated. They typically correspond to mixing ratios in the range 10 −8 -10 −10 , depending upon the strength of the observed transition. It should be noted that a 30 m antenna operating at 230 GHz remains very competitive, especially for small objects (e.g. Io) with large dilution factors. Heterodyne observations of Triton and Pluto appear beyond the limit of detection.
Published: 1995
Full Text: View/download PDF

29. Near-ir spectroscopy of Jupiter at the time of comet Shoemaker-Levy 9 Impacts: Emissions of CH4, H3+and H2

Author: Pierre Drossart, G. Wiedemann, R. Schulz, J. Crovisier, J. A. Stüwe, and Th. Encrenaz
Subjects: Sunlight, chemistry.chemical_compound, Geophysics, Haze, chemistry, Near-infrared spectroscopy, Hydrogen molecule, Comet, General Earth and Planetary Sciences, Environmental science, Atmospheric sciences, Jovian, Methane
Abstract: Near-infrared emissions of the SL9 impact sites of Jupiter have been recorded on July 16-18, 1994, at ESO (La Silla, Chile). A very strong emission of methane was recorded between 3.50 and 3.56 μm, shortly after impact H, showing evidence for a temporary increase of the Jovian stratospheric temperature. Emissions of H 2 (2.12 μm) and H 3 + (3.53 μm) were also detected above some of the impact sites, several hours after the impacts. The observed H 3 + emissions, however, seem to be at least partly contaminated by the southern aurora. A strong continuum was also detected at 2.12 μm over most of the impact sites, presumably due to intense scattering of reflected sunlight by stratospheric haze.
Published: 1995
Full Text: View/download PDF

30. Metallic emission lines during the impacts L and Q1of comet P/Shoemaker Levy 9 in Jupiter

Author: A. Barucci, J. Crovisier, M. Roos-Serote, Françoise Roques, M. Fulchignoni, Jean Lecacheux, and Pierre Drossart
Subjects: Physics, Comet, Astronomy, Spectral line, Jupiter, Metal, Geophysics, Observatory, visual_art, visual_art.visual_art_medium, General Earth and Planetary Sciences, Emission spectrum, Spectroscopy, Line (formation)
Abstract: High resolution spectroscopy of the impacts and impact sites of comet P/Shoemaker-Levy 9 in Jupiter has been performed at the Pic-du-Midi observatory, France. The transient emission of seven emission lines from five different metals (Na, Fe, Ca, Li, K) and of the Hα line have been identified in spectra from the fresh impact sites of fragments L and Q1.
Published: 1995
Full Text: View/download PDF

31. Chemical and thermal response of Jupiter's atmosphere following the impact of comet Shoemaker–Levy 9

Author: J. Crovisier, A. Marten, A. Sievers, Bruno Bézard, Pierre Colom, E. Lellouch, T. Encrenaz, Gabriel Paubert, Darrell F. Strobel, Michel C. Festou, D. Gautier, Didier Despois, R. Moreno, and Dominique Bockelée-Morvan
Subjects: Carbon Monoxide, Multidisciplinary, Extraterrestrial Environment, Atmosphere, Carbon Compounds, Inorganic, Comet, Sulfur Oxides, Temperature, Sulfides, Carbon, Jovian, Astrobiology, Jupiter, chemistry.chemical_compound, chemistry, Planet, Emission spectrum, Stratosphere, Carbon monoxide
Abstract: In July 1994, the collisions of the fragments of comet Shoemaker-Levy 9 with Jupiter resulted in dramatic changes in the planet's atmosphere. Observations of the events suggest that the composition and thermal properties of the atmosphere were considerably modified at the impact sites, with the changes persisting for times lasting from minutes to weeks (see, for example, refs 1-4). Here we report observations of the impact sites at millimetre wave-lengths, which reveal strong emission lines associated with carbon monoxide, carbonyl sulphide and carbon monosulphide. The abundance of carbon monoxide in the jovian atmosphere is normally very low; carbonyl sulphide and carbon monosulphide, on the other hand, have not hitherto been detected. We find that the largest fragments (G and K) each produced approximately 10(14) g of carbon monoxide, 3 x 10(12) g of carbonyl sulphide and 3 x 10(11) g of carbon monosulphide, most probably by shock-induced chemical reactions. Our observations also place firm constraints on the thermal response of Jupiter's stratosphere to the impacts.
Published: 1995
Full Text: View/download PDF

32. Thermal and shape properties of asteroid (21) Lutetia from Herschel observations around the Rosetta flyby

Author: Bruno Altieri, Benoit Carry, Michael Kueppers, E. Dotto, B. Gónzalez-García, M. A. Barucci, A. Llorente, Thomas Mueller, M. Sanchez Portal, Dominique Bockelée-Morvan, P. Garcia-Lario, M. Sierra, J. Crovisier, A. P. Marston, I. Valtchanov, R. Lorente, Laurence O'Rourke, Kathrin Altwegg, R. Schulz, R. Vavrek, B. Bhattacharya, D. Teyssier, Olivier Groussin, M. R. Kidger, Laurent Jorda, Herschel Science Centre, European Space Agency (ESA), 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), European Space Astronomy Centre (ESAC), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Physikalisches Institut [Bern], Universität Bern [Bern], Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Roma (OAR), Istituto Nazionale di Astrofisica (INAF), ISO Data Centre (ESA - Espagne), Herschel Science Centre (ESA Espagne), Haematology Service, University Hospital Joan XXIII, IISPV, Rovira and Virgili University, University of Utrecht, Utrecht University [Utrecht], Herschel Science Center [Madrid], European Space Agency (ESA)-European Space Agency (ESA), Agence Spatiale Européenne = European Space Agency (ESA), 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), and Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA)
Subjects: [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, Infrared, Astronomy, Astronomy and Astrophysics, Observable, Photometer, Albedo, 01 natural sciences, law.invention, Far infrared, Impact crater, 13. Climate action, Space and Planetary Science, Asteroid, law, Geometric albedo, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: International audience; Prior to and around the Rosetta flyby of (21) Lutetia, the Herschel Space Observatory performed a collaborative observation campaign with its two photometers observing the asteroid in the far infrared, at wavelengths not covered by Rosetta's instruments. The Herschel observations, fed into a thermophysical model (TPM) using as input a shape model based on in-situ images, were also further correlated with similar to 70 multi-wavelength observations of Lutetia. We confirm the geometric albedo measured by Rosetta, derive a H-mag value based upon the effective diameter of the asteroid and point to (21) Lutetia having an extremely low thermal inertia (5J m(-2) s(-0.5) K-1). This thermal inertia is only possible through the existence of a significant amount of small scale roughness which is not directly observable by the OSIRIS (Optical, Spectroscopic, and Infrared Imaging System) instrument on-board Rosetta. In addition, our results point to the existence of a hill/crater surface feature located on the asteroids southern region not observed by Rosetta. From our results, we conclude that only through the merging of in situ and remote sensing observations can a true global picture be obtained of this asteroid. (C) 2012 Elsevier Ltd. All rights reserved.
Published: 2012
Full Text: View/download PDF

33. Ammonia and other parent molecules in comet 10P/Tempel 2 from Herschel /HIFI and ground-based radio observations

Author: N. Dello Russo, M. de Val-Borro, R. Moreno, Slawomira Szutowicz, Dariusz C. Lis, M. R. Kidger, Michael Küppers, Ronald J. Vervack, Dominique Bockelée-Morvan, HssO Team, N. Biver, Jérémie Boissier, Paul Hartogh, Harold A. Weaver, J. Crovisier, Gabriel Paubert, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Instituto de Astrofisica de Canarias (IAC), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Max Planck Institute for Solar System Research (MPS), Max-Planck-Institut für Sonnensystemforschung (MPS), Biologie et écologie tropicale et méditerranéenne [2007-2010] (BETM), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Comet, FOS: Physical sciences, Astrophysics, 7. Clean energy, 01 natural sciences, law.invention, Telescope, Ammonia, chemistry.chemical_compound, Far infrared, law, 0103 physical sciences, Molecule, 010303 astronomy & astrophysics, Hyperfine structure, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Line (formation), Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS]Physics [physics], Astronomy and Astrophysics, 3. Good health, Outgassing, chemistry, 13. Climate action, Space and Planetary Science, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: The Jupiter-family comet 10P/Tempel 2 was observed during its 2010 return with the Herschel Space Observatory. We present here the observation of the (J, K) = (1, 0)-(0, 0) transition of ammonia at 572 GHz in this comet with the Heterodyne Instrument for the Far Infrared (HIFI) of Herschel. We also report on radio observations of other molecules (HCN, CH3OH, H2S and CS) obtained during the 1999 return of the comet with the CSO telescope and the JCMT, and during its 2010 return with the IRAM 30-m telescope. Molecular abundances relative to water are 0.09%, 1.8%, 0.4%, and 0.08% for HCN, CH3OH, H2S, and CS, respectively. An abundance of 0.5% for NH3 is obtained, which is similar to the values measured in other comets. The hyperfine structure of the ammonia line is resolved for the first time in an astronomical source. Strong anisotropy in the outgassing is present in all observations from 1999 to 2010 and is modelled to derive the production rates., 6 pages and 8 figures. Accepted for publication in Astronomy & Astrophysics
Published: 2012
Full Text: View/download PDF

34. Observations of OH in P/Swift-Tuttle and in several recent weak comets with the Nançay radio telescope

Author: Laurent Jorda, Dominique Bockelée-Morvan, Pierre Colom, J. Crovisier, G. Bourgois, and E. Gérard
Subjects: Physics, Radio telescope, Space and Planetary Science, Comet, Astronomy, Astronomy and Astrophysics, Astrophysics, Background radiation, Radio astronomy, Production rate
Abstract: The OH radio lines at 18 cm were monitored in six comets with the Nancay radio telescope in 1992 and early 1993: Zanotta-Brewington 1991g 1 , Bradfield 1992b, Mueller 1991h 1 , Shoemaker-Levy 1991a 1 , P/Swift-Tuttle 1992t and P/Schaumasse 1992x. Neither Bradfield 1992b nor Mueller 1991h 1 could be detected. Zanotta-Brewington 1991g 1 , Shoemaker-Levy 1991a 1 and P/Schaumasse 1992x were relatively weak comets with OH production rates of the order of 10 28 s −1 and required several hours of integration to be detected. P/Swift-Tuttle was observed and detected as early as mid-October 1992. The signal was much stronger than for the other comets, especially at the beginning of December 1992, when P/Swift-Tuttle was observed against galactic background radiation. The OH production rate was several 10 29 s −1 . All along the observations, the OH radio lines exhibited unusually high blueshifts, corresponding to gas bulk motions of 0.5–1.0 km s −1 towards the observer. This undoubtedly corresponds to the strong jets observed in optical images and to the important nongravitational forces that affect the orbit of this comet. P/Swift-Tuttle was still observed at Nancay at the beginning of January 1993 when the small solar elongation precluded optical observations. A summary of these observations and of the estimations of the OH production rates is presented.
Published: 1994
Full Text: View/download PDF

35. Direct detection of the Enceladus water torus with Herschel

Author: M. Kidger, Dominique Bockelée-Morvan, Frank Helmich, J. Crovisier, Miriam Rengel, Paul Hartogh, R. Moreno, N. Biver, Emmanuel Lellouch, T. Cassidy, Christopher Jarchow, Thibault Cavalié, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Max-Planck-Institut für Sonnensystemforschung (MPS), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics, 01 natural sciences, 7. Clean energy, symbols.namesake, 0103 physical sciences, submillimetre: planetary system, STRATOSPHERE, Enceladus, Space research, CARBON-MONOXIDE, 010303 astronomy & astrophysics, Stratosphere, Physics::Atmospheric and Oceanic Physics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, JUPITER, planets and satellites: individual: Saturn, ORIGIN, Astronomy, ASTRONOMY, Astronomy and Astrophysics, Torus, Scale height, PLUME, Gas torus, SATURNS ATMOSPHERE, Space and Planetary Science, Physics::Space Physics, symbols, VAPOR, Astrophysics::Earth and Planetary Astrophysics, Titan (rocket family), EMISSION, Water vapor, planets and satellites: individual: Enceladus, techniques: spectroscopic, SYSTEM
Abstract: International audience; Cryovolcanic activity near the south pole of Saturn's moon Enceladus produces plumes of H2O-dominated gases and ice particles, which escape and populate a torus-shaped cloud. Using submillimeter spectroscopy with Herschel, we report the direct detection of the Enceladus water vapor torus in four rotational lines of water at 557, 987, 1113, and 1670 GHz, and probe its physical conditions and structure. We determine line-of-sight H2O column densities of ~4 × 1013 cm-2 near the equatorial plane, with a ~50 000 km vertical scale height. The water torus appears to be rotationally cold (e.g. an excitation temperature of 16 K is measured for the 1113 GHz line) but dynamically excited, with non-Keplerian dispersion velocities of ~2 km s-1, and appears to be largely shaped by molecular collisions. From estimates of the influx rates of torus material into Saturn and Titan, we infer that Enceladus' activity is likely to be the ultimate source of water in the upper atmosphere of Saturn, but not in Titan's. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. HIFI has been designed and built by a consortium of institutes and university departments from across Europe, Canada and the United States under the leadership of SRON Netherlands Institute for Space Research, Groningen, The Netherlands and with major contributions from Germany, France and the US.Figures 4 and 5 are available in electronic form at http://www.aanda.org
Published: 2011
Full Text: View/download PDF

36. Earth-based detection of the millimetric thermal emission of the nucleus of comet 8P/Tuttle

Author: Laurent Jorda, R. Moreno, N. Biver, P. Colom, Dominique Bockelée-Morvan, P. L. Lamy, J. Crovisier, Olivier Groussin, E. Lellouch, Jérémie Boissier, Laboratoire d'Astrophysique de Marseille (LAM), 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), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Beaussier, Catherine
Subjects: 010504 meteorology & atmospheric sciences, Infrared, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics::High Energy Astrophysical Phenomena, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spitzer Space Telescope, 0103 physical sciences, Emissivity, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Instrumentation and Methods for Astrophysics, Plateau de Bure Interferometer, Astronomy, Astronomy and Astrophysics, Albedo, [PHYS.ASTR.EP] Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 13. Climate action, Space and Planetary Science, Millimeter, SPHERES, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Little is known about the physical properties of cometary nuclei. Apart from space mission targets, measuring the thermal emission of a nucleus is one of the few means to derive its size, independently of its albedo, and to constrain some of its thermal properties. This emission is difficult to detect from Earth but space telescopes (Infrared Space Observatory, Spitzer Space Telescope, Herschel Space Observatory) allow reliable measurements in the infrared and the sub-millimetre domains. We aim at better characterizing the thermal properties of the nucleus of comet 8P/Tuttle using multi-wavelentgh space- and ground-based observations, in the visible, infrared, and millimetre range. We used the Plateau de Bure Interferometer to measure the millimetre thermal emission of comet 8P/Tuttle at 240 GHz (1.25 mm) and analysed the observations with the shape model derived from Hubble Space Telescope observations and the nucleus size derived from Spitzer Space Telescope observations. We report on the first detection of the millimetre thermal emission of a cometary nucleus since comet C/1995 O1 Hale-Bopp in 1997. Using the two contact spheres shape model derived from Hubble Space Telescope observations, we constrained the thermal properties of the nucleus. Our millimetre observations are best match with: i) a thermal inertia lower than ~10 J K-1 m-2 s-1/2, ii) an emissivity lower than 0.8, indicating a non-negligible contribution of the colder sub-surface layers to the outcoming millimetre flux., Comment: 7 pages. Accepted for publication in Astronomy & Astrophysics
Published: 2011
Full Text: View/download PDF

37. The Surface Composition and Temperature of Asteroid 21 Lutetia As Observed by Rosetta/VIRTIS

Author: Maria Teresa Capria, M. Combes, G. Neukum, Johannes Benkhoff, Stefano Mottola, Pierre Drossart, Uwe Fink, D. Bockelee-Morvan, Vincenzo Orofino, R. W. Carlson, E. T. Encrenaz, M. C. De Sanctis, Davide Grassi, Uri Carsenty, F. Carraro, Michael R. Combi, Luigi Colangeli, M. A. Barucci, Fabrizio Capaccioni, E. Kuehrt, Ralf Jaumann, S. Giuppi, J. Crovisier, Vito Mennella, Federico Tosi, Sergio Fonti, Eleonora Ammannito, D. Tiphene, Wing-Huen Ip, Gianfranco Magni, Fredric W. Taylor, Angioletta Coradini, Gianrico Filacchione, Costanzo Federico, Jean-Pierre Bibring, M. I. Blecka, Pasquale Palumbo, Armando Blanco, G. Arnold, Yves Langevin, Giuseppe Piccioni, Ulrich Schade, G. P. Tozzi, Bernard Schmitt, Lorenza Giacomini, Stéphane Erard, Priscilla Cerroni, Giancarlo Bellucci, T. B. McCord, Coradini, A., Blanco, Armando, Fonti, Sergio, Orofino, Vincenzo, and …., et al
Subjects: Mineral hydration, education.field_of_study, Multidisciplinary, Spectral signature, Materials science, Infrared, Population, Imaging spectrometer, Lutetia, Regolith, Space weathering, Astrobiology, Asteroid, Rosetta, education, Virtis
Abstract: The Visible, InfraRed, and Thermal Imaging Spectrometer (VIRTIS) on Rosetta obtained hyperspectral images, spectral reflectance maps, and temperature maps of the asteroid 21 Lutetia. No absorption features, of either silicates or hydrated minerals, have been detected across the observed area in the spectral range from 0.4 to 3.5 micrometers. The surface temperature reaches a maximum value of 245 kelvin and correlates well with topographic features. The thermal inertia is in the range from 20 to 30 joules meter(-2) kelvin(-1) second(-0.5), comparable to a lunarlike powdery regolith. Spectral signatures of surface alteration, resulting from space weathering, seem to be missing. Lutetia is likely a remnant of the primordial planetesimal population, unaltered by differentiation processes and composed of chondritic materials of enstatitic or carbonaceous origin, dominated by iron-poor minerals that have not suffered aqueous alteration.
Published: 2011
Full Text: View/download PDF

38. A study of the distant activity of comet C/2006 W3 (Christensen) using Herschel and ground-based radio telescopes

Author: L. M. Lara, Trevor Fulton, Miriam Rengel, M. R. Kidger, G. A. Blake, R. Moreno, Emmanuel Jehin, E. Lellouch, Michael Küppers, David A. Naylor, C. Waelkens, D. C. Lis, T. de Graauw, E. A. Bergin, Jean Manfroid, M. I. Blecka, T. Encrenaz, M. de Val-Borro, L. Decin, J. Crovisier, Slawomira Szutowicz, Christopher Jarchow, Bart Vandenbussche, José Cernicharo, J. A. D. L. Blommaert, Damien Hutsemekers, N. Thomas, Paul Hartogh, Dominique Bockelée-Morvan, Alexander S. Medvedev, Sarah Leeks, Marek Banaszkiewicz, Rudolf Schieder, P. J. Encrenaz, F. Bensch, B. M. Swinyard, N. Biver, Martin Emprechtinger, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Rutherford Appleton Laboratory, Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Institut d'Astrophysique, Géophysique et Océanographie, Université de Liège, European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Instituto de Astrofisica de Andalucia, CSIC (IAA), Space Research Centre, Polish Academy of Sciences (Wroclaw), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Blue Sky Spectroscopy (BSS), Herschel Science Center, ESAC/ESA, Astronomy Department, University of Michigan, Centro de Astrobiología, Consejo Superior de Investigaciones Científicas (CSIC)/Instituto Nacional de Técnica Aeroespacial (INTA) (CAB), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Instrumentation et télédétection, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Dynamique des milieux interstellaires et plasmas stellaires, SRON Netherlands Institute for Space Research, Department of Physics, University of Lethbridge, Lulea University of Technology (LTU), and University of Bern (UBERN)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, Range (particle radiation), Continuum (design consultancy), Comet, FOS: Physical sciences, Astronomy and Astrophysics, Coma (optics), Astrophysics, Spectral line, Radio telescope, Spire, Space and Planetary Science, Spectral energy distribution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: Comet C/2006 W3 (Christensen) was observed in November 2009 at 3.3 AU from the Sun with Herschel. The PACS instrument acquired images of the dust coma in 70- and 160-micrometers filters, and spectra covering several H2O rotational lines. Spectra in the range 450-1550 GHz were acquired with SPIRE. The comet emission continuum from 70 to 672 micrometers was measured, but no lines were detected. The spectral energy distribution indicates thermal emission from large particles and provides a measure of the size distribution index and dust production rate. The upper limit to the water production rate is compared to the production rates of other species (CO, CH3OH, HCN, H2S, OH) measured with the IRAM 30-m and Nancay telescopes. The coma is found to be strongly enriched in species more volatile than water, in comparison to comets observed closer to the Sun. The CO to H2O production rate ratio exceeds 220%. The dust to gas production rate ratio is on the order of 1., Accepted for publication in Astronomy & Astrophysics (special issue on Herschel first results)
Published: 2010
Full Text: View/download PDF

39. Martian atmosphere as observed by VIRTIS-M on Rosetta spacecraft

Author: Sergio Fonti, Angioletta Coradini, Yves Langevin, G. P. Tozzi, Gianrico Filacchione, Michael R. Combi, Dominique Bockelée-Morvan, Didier Tiphene, Stefano Mottola, Bernard Schmitt, J. Crovisier, M. A. Barucci, Gianfranco Magni, Giovanna Rinaldi, Armando Blanco, Eleonora Ammannito, Vincenzo Orofino, Costanzo Federico, Pierre Drossart, Pasquale Palumbo, Ralf Jaumann, Luigi Colangeli, Wing-Huen Ip, Giancarlo Bellucci, Priscilla Cerroni, M. T. Capria, Vittorio Formisano, Giuseppe Piccioni, J. P. Bibring, Fredric W. Taylor, T. Encrenaz, Pgj Irwin, Uwe Fink, Gabriele Arnold, Paulina Wolkenberg, R. W. Carlson, G. Neukum, Davide Grassi, Johannes Benkhoff, M. Combes, Fabrizio Capaccioni, Stéphane Erard, Heike Rauer, T. B. McCord, Vito Mennella, Federico Tosi, E. Kuehrt, M. C. De Sanctis, Uri Carsenty, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Observatoire de Paris, Université Paris sciences et lettres (PSL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Dipartimento di Fisica, Università di Lecce, Jet Propulsion Laboratory, California Institute of Technology (JPL), INAF-Osservatorio Astronomico di Capodimonte (INAF-OAC), Atmospheric, Oceanic, and Space Science Department, University of Michigan (AOSS), Università degli Studi di Perugia = University of Perugia (UNIPG), Department of Planetary Sciences, Lunar and Planetary Laboratory, University of Arizona (LPL), Graduate Institute of Astronomy, Atmospheric, Oceanic and Planetary Physics, Department of Physics, Clarendon Laboratory, University of Oxford, Bear Fight Center, Space Science Institute, Winthrop, Dipartimento di Scienze Applicate, Università Parthenope di Napoli, Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and INAF-Osservatorio Astrofisico di Arcetri (INAF-OAA)
Subjects: MESH: Rosetta mission, Atmospheric Science, Daytime, Opacity, martian atmosphere, virtis, rosetta, Solar zenith angle, Soil Science, Aquatic Science, Oceanography, Atmospheric sciences, Planetary Sciences: Solid Surface Planets: Instruments and techniques, Atmosphere, Geochemistry and Petrology, MESH: CO2, Earth and Planetary Sciences (miscellaneous), Planetary Sciences: Solid Surface Planets: Atmospheres (0343, Radiometric calibration, Earth-Surface Processes, Water Science and Technology, Ecology, Spectrometer, Paleontology, Forestry, Mars Exploration Program, Atmosphere of Mars, Planetary Sciences: Solid Surface Planets: Remote sensing, 1060), Geophysics, Space and Planetary Science, MESH: temperature profile, Environmental science, MESH: Mars atmosphere, MESH: 67P/Churyumov‐Gerasimenko, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience; The Rosetta spacecraft accomplished a flyby of Mars on its way to 67P/Churyumov-Gerasimenko on 25 February 2007. In this paper we describe the measurements obtained by the M channel of the Visual and Infrared Thermal Imaging Spectrometer (VIRTIS-M) and the first scientific results derived from their analysis. The broad spectral coverage of the VIRTIS-M in the IR permitted the study of various phenomena occurring in the Martian atmosphere; observations were further exploited to achieve accurate absolute radiometric calibration. Nighttime data from the VIRTIS-M constrain the air temperature profile in the lower atmosphere (5-30 km), using variations in CO2 opacity at 4.3 mum. A comparison of this data with the global circulation model (GCM) by Forget et al. (1999) shows a trend of slightly higher air temperature in the VIRTIS-M retrievals; this is accompanied by the presence of moderate decreases (˜5 K) in large sections of the equatorial region. This is potentially related to the occurrence of water ice clouds. Daytime data from the VIRTIS-M reveal CO2 non-local thermodynamic equilibrium emission in the high atmosphere. A mapping of emission intensity confirms its strict dependence on solar zenith angle. Additionally, devoted limb observations allowed the retrieval of vertical emission intensity profiles, indicating a peak around 105 km in southern tropical regions. Ozone content can be effectively monitored by the emission of O2 (a1Deltag) at 1.27 mum. Retrieved emission intensity shows that polar regions are particularly rich in ozone. Aerosol scattering was observed in the 1-2.5 mum region above the night region above the night disk, suggesting the occurrence of very high noctilucent clouds.
Published: 2010
Full Text: View/download PDF

40. High-dispersion infrared spectroscopic observations of comet 8P/Tuttle with VLT/CRIRES

Author: Kobayashi D. Bockelee-Morvan H. Kawakita N. Dello Russo E. Jehin J. Manfroid A. Smette D. Hutsemekers J. Stuwe M. Weiler C. Arpigny N. Biver A. Cochran J. Crovisier P. Magain H. Sana R. Schulz R.J. Vervack H Weaver J.M. Zucconi, H., Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)
Subjects: ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2010

41. 'TNOs are Cool': A survey of the trans-Neptunian region. I. Results from the Herschel science demonstration phase (SDP)

Author: B. M. Swinyard, Miriam Rengel, L. M. Lara, T. G. Mueller, Paul Hartogh, S. Fornasier, R. Moreno, Nicolas Thomas, Esa Vilenius, Olivier Hainaut, Daniel Hestroffer, Jonathan Horner, Pablo Santos-Sanz, E. Dotto, John Stansberry, David Trilling, A. Delsanti, M. R. Kidger, P. J. Gutierrez, Tanya Lim, Rene Duffard, Alain Doressoundiram, J. Crovisier, Michael Mueller, Florence Henry, Michael Mommert, Pedro Lacerda, Cs. Kiss, Olivier Groussin, Audrey Thirouin, Alan W. Harris, Silvia Protopapa, Antonella Barucci, J. L. Ortiz, E. Lellouch, Max-Planck-Institut für Extraterrestriche Physik (MPE), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Arizona (UoA), Konkoly Observatory, Research Center for Astronomy and Earth Sciences, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), 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), Instituto de Astrofisica de Andalucia, CSIC (IAA), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Department of Physics and Astronomy, Durham University, Queen's University [Belfast] (QUB), Space Science and Technology Department, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxon UK, Department of Physics and Astronomy, Northern Arizona University, Flagstaff, INAF-Osservatorio Astronomico di Roma (INAF-OAR), European Southern Observatory (ESO), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Herschel Science Center, ESAC/ESA, University of Bern (UBERN), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institute of Planetary Research, German Aerospace Center (DLR), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Centre National de la Recherche Scientifique (CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de Probabilités et Modèles Aléatoires (LPMA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Pierre et Marie Curie - Paris 6 (UPMC), Max-Planck-Institut für Sonnensystemforschung (MPS), INAF - Osservatorio Astronomico di Roma (OAR), Istituto Nazionale di Astrofisica (INAF), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Solar System, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astrophysics, Color temperature, 01 natural sciences, 0103 physical sciences, Thermal, Range (statistics), Kuiper belt: general / methods: observational / techniques: photometric / instrumentation: photometers / infrared: planetary systems, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Debris disk, Mode (statistics), Astronomy and Astrophysics, Centaur, Albedo, Astrophysics - Astrophysics of Galaxies, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: The goal of the Herschel Open Time Key programme "TNOs are Cool!" is to derive the physical and thermal properties for a large sample of Centaurs and trans-Neptunian objects (TNOs), including resonant, classical, detached and scattered disk objects. We present results for seven targets either observed in PACS point-source, or in mini scan-map mode. Spitzer-MIPS observations were included for three objects. The sizes of these targets range from 100 km to almost 1000 km, five have low geometric albedos below 10%, (145480) 2005 TB190 has a higher albedo above 15%. Classical thermal models driven by an intermediate beaming factor of $\eta$=1.2 or $\eta$-values adjusted to the observed colour temperature fit the multi-band observations well in most cases. More sophisticated thermophysical models give very similar diameter and albedo values for thermal inertias in the range 0-25 Jm-2s-0.5K-1, consistent with very low heat conductivities at temperatures far away from the Sun. The early experience with observing and model strategies will allow us to derive physical and thermal properties for our complete Herschel TNO sample of 140 targets as a benchmark for understanding the solar system debris disk, and extra-solar ones as well., Comment: 5 pages, 2 figures, accepted for publication in the A&A Herschel Special Issue
Published: 2010
Full Text: View/download PDF

42. The Herschel-SPIRE submillimetre spectrum of Mars

Author: José Cernicharo, M. de Val-Borro, L. Decin, J. A. D. L. Blommaert, Ganna Portyankina, M. Renge, R. Moreno, Edwin A. Bergin, M. I. Blecka, Sarah Leeks, B. M. Swinyard, T. Encrenaz, Michael Kueppers, Geoffrey A. Blake, J. Crovisier, Emmanuel Jehin, N. Biver, Matthew Joseph Griffin, E. Lellouch, L. M. Lara, F. Bensch, Dariusz C. Lis, P. J. Encrenaz, G. S. Orton, G. Davis, Daphne Stam, C. Waelkens, Alexander S. Medvedev, Dominique Bockelée-Morvan, H. J. Walker, Christopher Jarchow, Régis Courtin, Bart Vandenbussche, Eva Verdugo, Paul Hartogh, Marek Banaszkiewicz, Rudolf Schieder, Hideo Sagawa, Nicolas Thomas, Thibault Cavalié, Slawomira Szutowicz, Trevor Fulton, M. R. Kidger, Sunil Sidher, T. de Graauw, David A. Naylor, F. Billebaud, Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Center for Mathematics and Physics, University of Aizu, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Space Research Centre of Polish Academy of Sciences (CBK), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Observatoire de Paris - Site de Paris (OP), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Department of Ecology and Evolutionary Biology [Princeton], Princeton University, Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), SRON Netherlands Institute for Space Research (SRON), Centre Alexis Vautrin (CAV), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure - Paris (ENS-PSL)
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Fourier transform spectrometers, FOS: Physical sciences, Astrophysics, 01 natural sciences, Planet, 0103 physical sciences, Mixing ratio, Calibration, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, QB, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Atmospheric models, Detector, Astronomy and Astrophysics, Mars Exploration Program, Computational physics, 13. Climate action, Space and Planetary Science, Earth and Planetary Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Data reduction
Abstract: We have obtained the first continuous disk averaged spectrum of Mars from 450 to 1550 Ghz using the Herschel-SPIRE Fourier Transform Spectrometer. The spectrum was obtained at a constant resolution of 1.4 GHz across the whole band. The flux from the planet is such that the instrument was operated in "bright source" mode to prevent saturation of the detectors. This was the first successful use of this mode and in this work we describe the method used for observing Mars together with a detailed discussion of the data reduction techniques required to calibrate the spectrum. We discuss the calibration accuracy obtained and describe the first comparison with surface and atmospheric models. In addition to a direct photometric measurement of the planet the spectrum contains the characteristic transitions of 12CO from J 5-4 to J 13-12 as well as numerous H2O transitions. Together these allow the comparison to global atmospheric models allowing the mean mixing ratios of water and 12CO to be investigated. We find that it is possible to match the observed depth of the absorption features in the spectrum with a fixed water mixing ratio of 1 x 10-4 and a 12CO mixing ratio of 9 x 10-4, Accepted for publication in Astronomy&Astrophysics, Herschel First Results special issue
Published: 2010
Full Text: View/download PDF

43. Water and related chemistry in the solar system. A guaranteed time key programme for Herschel

Author: Slawomira Szutowicz, Michael Küppers, M. R. Kidger, N. Biver, David A. Naylor, Sunil Sidher, Emmanuel Jehin, M. I. Blecka, Dariusz C. Lis, Jean Manfroid, A. Gonzalez, Rudolf Schieder, Christopher Jarchow, Marek Banaszkiewicz, F. Billebaud, Régis Courtin, T. de Graauw, Ganna Portyankina, B. M. Swinyard, José Cernicharo, H. Walker, L. Decin, Bart Vandenbussche, F. Bensch, Gary R. Davis, P. J. Encrenaz, E. Verdugo, J. Crovisier, Thibault Cavalié, Paul Hartogh, A. de Lange, G. S. Orton, Hideo Sagawa, Nicolas Thomas, E. A. Bergin, R. Lorente, Alexander S. Medvedev, Dominique Bockelée-Morvan, G. D. Thornhill, Daphne Stam, Damien Hutsemekers, J. A. D. L. Blommaert, M. Sanchez-Portal, Geoffrey A. Blake, L. M. Lara, Emmanuel Lellouch, Thérèse Encrenaz, Miriam Rengel, R. Moreno, C. Waelkens, Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Observatoire de Paris - Site de Paris (OP), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Department of Ecology and Evolutionary Biology [Princeton], Princeton University, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Departamento de Biologia Celular, Facultad de Biologia, Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), European Southern Observatory (ESO), Laboratorio de Ecologia Isotopica, Centro de Energia Nuclear na Agricultura (CENA), California Institute of Technology (CALTECH), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Center for Mathematics and Physics, University of Aizu, SRON Netherlands Institute for Space Research (SRON), Centre Alexis Vautrin (CAV), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Harvard University-Smithsonian Institution, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure - Paris (ENS-PSL)
Subjects: Herschel spaceobservatory Water Mars Giant planets Titan Comets, Solar System, Outer planets, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 01 natural sciences, Astrobiology, Interplanetary dust cloud, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Enceladus, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Chemistry, Astronomy, Astronomy and Astrophysics, Mars Exploration Program, Atmosphere of Mars, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics
Abstract: International audience; "Water and related chemistry in the Solar System" is a Herschel Space Observatory Guaranteed-Time Key Programme. This project, approved by the European Space Agency, aims at determining the distribution, the evolution and the origin of water in Mars, the outer planets, Titan, Enceladus and the comets. It addresses the broad topic of water and its isotopologues in planetary and cometary atmospheres. The nature of cometary activity and the thermodynamics of cometary comae will be investigated by studying water excitation in a sample of comets. The D/H ratio, the key parameter for constraining the origin and evolution of Solar System species, will be measured for the first time in a Jupiter-family comet. A comparison with existing and new measurements of D/H in Oort-cloud comets will constrain the composition of pre-solar cometary grains and possibly the dynamics of the protosolar nebula. New measurements of D/H in giant planets, similarly constraining the composition of proto-planetary ices, will be obtained. The D/H and other isotopic ratios, diagnostic of Mars' atmosphere evolution, will be accurately measured in H2O and CO. The role of water vapor in Mars' atmospheric chemistry will be studied by monitoring vertical profiles of H2O and HDO and by searching for several other species (and CO and H2O isotopes). A detailed study of the source of water in the upper atmosphere of the Giant Planets and Titan will be performed. By monitoring the water abundance, vertical profile, and input fluxes in the various objects, and when possible with the help of mapping observations, we will discriminate between the possible sources of water in the outer planets (interplanetary dust particles, cometary impacts, and local sources). In addition to these inter-connected objectives, serendipitous searches will enhance our knowledge of the composition of planetary and cometary atmospheres.
Published: 2009
Full Text: View/download PDF

44. Interferometric imaging of carbon monoxide in comet C/1995 O1 (Hale-Bopp): evidence for a strong rotating jet

Author: Jérémie Boissier, R. Moreno, Florence Henry, Didier Despois, J. Crovisier, Dominique Bockelée-Morvan, P. Colom, N. Biver, J. Wink, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Biologie et écologie tropicale et méditerranéenne [2007-2010] (BETM), Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Perpignan Via Domitia (UPVD), and Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Coma (optics), Astrophysics, Rotation, 01 natural sciences, Spectral line, 0103 physical sciences, Angular resolution, Spectral resolution, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Jet (fluid), Astrophysics::Instrumentation and Methods for Astrophysics, Plateau de Bure Interferometer, Astronomy and Astrophysics, 13. Climate action, Space and Planetary Science, Earth and Planetary Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Observations of the CO J(1-0) 115 GHz and J(2-1) 230 GHz lines in comet C/1995 O1 (Hale-Bopp) were performed with the IRAM Plateau de Bure interferometer on 11 March, 1997. The observations were conducted in both single-dish (ON-OFF) and interferometric modes with 0.13 km s-1 spectral resolution. Images of CO emission with 1.7 to 3" angular resolution were obtained. The ON-OFF and interferometric spectra show a velocity shift with sinusoidal time variations related to the Hale-Bopp nucleus rotation of 11.35 h. The peak position of the CO images moves perpendicularly to the spin axis direction in the plane of the sky. This suggests the presence of a CO jet, which is active night and day at about the same extent, and is spiralling with nucleus rotation. The high quality of the data allows us to constrain the characteristics of this CO jet. We have developed a 3-D model to interpret the temporal evolution of CO spectra and maps. The CO coma is represented as the combination of an isotropic distribution and a spiralling gas jet, both of nucleus origin. Spectra and visibilities (the direct output of interferometric data) analysis shows that the CO jet comprises ~40% the total CO production and is located at a latitude ~20 degrees North on the nucleus surface. Our inability to reproduce all observational characteristics shows that the real structure of the CO coma is more complex than assumed, especially in the first thousand kilometres from the nucleus. The presence of another moving CO structure, faint but compact and possibly created by an outburst, is identified., 20 pages, 26 figures. Accepted for publication in Astronomy & Astrophysics
Published: 2009
Full Text: View/download PDF

45. Neutral Atmospheres

Author: I. C. F. Mueller-Wodarg, D. F. Strobel, J. I. Moses, J. H. Waite, J. Crovisier, R. V. Yelle, S. W. Bougher, and R. G. Roble
Published: 2009
Full Text: View/download PDF

46. Radio Monitoring of 9P/Tempel 1 Outgassing and Gas Released by the Impact

Author: Åke Hjalmarson, Sun Kwok, R. Moreno, P. Colom, Michael Olberg, N. Biver, Aage Sandqvist, J. Crovisier, H. G. Floren, Dominique Bockelée-Morvan, M. C. Sumner, Urban Frisk, Dariusz C. Lis, Alain Lecacheux, Gabriel Paubert, Jérémie Boissier, Anders Winnberg, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Radio telescope, Physics, Rotation period, Outgassing, Comet, Astronomy, Satellite, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Production rate
Abstract: As part of the international observing campaign in support of the NASA Deep Impact mission to comet 9P/Tempel 1, we conducted a monitoring of its outgassing at radio wavelengths. OH observations conducted at the Nancay radio telescope provided a 4-month monitoring of the comet from March to July, followed by the observation of H2O with the Odin satellite from June to August 2005. The peak of outgassing was found to be around 1028 molec. s-1 between May and July. Observations of HCN conducted with the IRAM 30 m radio telescope in May 2005 showed a variation of the production rate with a period of 1.73±0.10 days, consistent with the rotation period of the nucleus.
Published: 2009
Full Text: View/download PDF

47. A multi-wavelength simultaneous study of the composition of the Halley Family Comet 8P/Tuttle

Author: Hugues Sana, Anita L. Cochran, N. Biver, Harold A. Weaver, Alain Smette, Jean Manfroid, J.-M. Zucconi, Emmanuel Jehin, J. A. Stüwe, Heike Rauer, J. Crovisier, N. Dello Russo, Hideyo Kawakita, Damien Hutsemekers, Claude Arpigny, M. Weiler, Pierre Magain, Dominique Bockelée-Morvan, Hitomi Kobayashi, Rita Schulz, Ronald J. Vervack, Institut d'Astrophysique, Géophysique et Océanographie, Université de Liège, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Applied Physics Laboratory, Johns Hopkins University, Kyoto Sangyo University, Research and Scientific Support Department, ESA-ESTEC (RSSD), European Southern Observatory (ESO), Leiden Observatory, Department of Astronomy and McDonald Observatory, University of Texas, Austin, DLR Institut für Planetenerkundung, Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)
Subjects: Physics, Very Large Telescope, spectroscopy, Infrared, comet 8P/Tuttle, Comet, Infrared spectroscopy, Astronomy, Astronomy and Astrophysics, Astrophysics, gas composition, Jupiter, Planetary science, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), comets, Spectroscopy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Long-slit spectroscopy
Abstract: International audience; We report on simultaneous optical and infrared observations of the Halley Family comet 8P/Tuttle performed with the ESO Very Large Telescope. Such multi-wavelength and coordinated observations are a good example of what can be done to support space missions. From high resolution optical spectroscopy of the CN (0,0) 388 nm and NH2 (0,9,0) 610 nm bands using UVES at UT2 we determined 12C/13C = 90 ± 10 and 14N/15N = 150 ± 20 in CN and we derived a nuclear spin temperature of NH3 of 29 ± 1 K. These values are similar to those found in Oort-Cloud and Jupiter Family comets. From low resolution long slit spectroscopy with FORS1 at UT2 we determined the CN, C3 and C2 production rates and the parent and daughter scale lengths up to 5.2 105 km tailward. From high resolution IR spectroscopy with CRIRES at UT1 we measured simultaneously the production rates and mixing ratios of H2O, HCN, C2H2, CH4, C2H6, and CH3OH.
Published: 2009
Full Text: View/download PDF

48. Microwave observations of hydrogen sulfide and searches for other sulfur compounds in comets Austin (1989c1) and Levy (1990c)

Author: Gabriel Paubert, P. Colom, Dominique Bockelée-Morvan, Didier Despois, and J. Crovisier
Subjects: Chemistry, Hydrogen sulfide, Comet, Rotational transition, chemistry.chemical_element, Astronomy and Astrophysics, Astrophysics, Sulfur, Astrobiology, chemistry.chemical_compound, Space and Planetary Science, Radiative transfer, Molecule, Chemical composition, Line (formation)
Abstract: We detected hydrogen sulfide through observations of its 1 10 -1 01 rotational line at 2 mm in Comets Austin (1989c1) and Levy (1990c) using the IRAM 30-m radiotelescope. In Comet Levy, the 2 20 -2 11 line of H 2 S was also observed; the relative intensities of the two lines suggest a cold rotational distribution for H 2 S. We also unsuccessfully searched for other sulfur molecular species in Comet Levy: SO 2 , OCS, H 2 CS. From these observations, we derive molecular production rates using an out-of-equilibrium excitation model which takes into account collisions and vibrational radiative excitation. The infereed hydrogen sulfide production rate is about 0.002 that of water for both comets. H 2 S and the parent of the CS radical appear to be the main depositories of sulfur in cometary volatiles. This element seems to be depleted in cometary volatiles with respect to cosmic abundance. The presence in cometary nuclei of H 2 S, which is a highly volatile molecule, is a clue that comets formed and remained stored at very cold temperatures.
Published: 1991
Full Text: View/download PDF

49. High-resolution infrared spectrum of CO on Mars: Evidence for emission lines

Author: E. Lellouch, Jean-Pierre Maillard, J. Crovisier, T. Encrenaz, and F. Billebaud
Subjects: Materials science, Infrared, business.industry, Astronomy and Astrophysics, Rotational temperature, Atmosphere of Mars, Mars Exploration Program, Molecular physics, Spectral line, Optics, Space and Planetary Science, Excited state, Emission spectrum, Spectral resolution, business
Abstract: Very-high resolution observations of Mars at 5 μm allowed detection of emission lines belonging to the 1-0 and 2-1 vibrational bands of CO. These transitions can be produced either by fluorescence following solar infrared excitation or by photolysis of CO2 yielding CO in excited states. A quantitative model taking into account these two NLTE mechanisms successfully reproduces the observed intensities. The rotational distribution of the 2-1 band is consistent with a rotational temperature of 130 ± 30 K at an altitude of 55 km.
Published: 1991
Full Text: View/download PDF

50. Virtis: An Imaging Spectrometer for the Rosetta Mission

Author: Uwe Fink, Bortolino Saggin, Sergio Fonti, Eleonora Ammannito, Costanzo Federico, Vittorio Formisano, M.C. Desanctis, M. I. Blecka, Pasquale Palumbo, Bernard Schmitt, Michael R. Combi, Antonella Barucci, Luigi Colangeli, Thomas B. McCord, Wing-Huen Ip, Heike Rauer, Maria Teresa Capria, Stéphane Erard, Gabriele Arnold, Gianrico Filacchione, Francesco Angrilli, G. Bianchini, Pierre Drossart, Jean-Pierre Bibring, Yves Langevin, Stefano Mottola, G. Neukum, Giulio Magni, E. T. Encrenaz, Angioletta Coradini, R. W. Carlson, G. P. Tozzi, Johannes Benkhoff, Uri Carsenty, M. Combes, E. Kuehrt, Giuseppe Piccioni, Priscilla Cerroni, Ralf Jaumann, Fabrizio Capaccioni, Vito Mennella, J. Crovisier, Dominique Bockelée-Morvan, Didier Tiphene, Giancarlo Bellucci, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), German Aerospace Center (DLR), Dipartimento di Ingegneria Meccanica, Università degli Studi di Padova = University of Padua (Unipd), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), INAF - Osservatorio Astronomico di Capodimonte (OAC), Space Physics Research Laboratory [Ann Arbor] (SPRL), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Università degli Studi di Perugia = University of Perugia (UNIPG), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Dipartimento di Fisica, Università degli studi di Lecce, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Consiglio Nazionale delle Ricerche (CNR), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Universita degli Studi di Padova, European Space Agency (ESA), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Polska Akademia Nauk (PAN), Università degli Studi di Perugia (UNIPG), Max-Planck-Institut für Sonnensystemforschung (MPS), and California Institute of Technology (CALTECH)-NASA
Subjects: spectroscopy, 010504 meteorology & atmospheric sciences, Comet, Imaging spectrometer, Context (language use), space mission, 01 natural sciences, 7. Clean energy, Space exploration, Comets, Space missions, Spectroscopy, Astronomy and Astrophysics, Space and Planetary Science, Astrobiology, law.invention, Orbiter, law, 0103 physical sciences, comets, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Mars Exploration Program, space missions, Planetary science, 13. Climate action, Asteroid, Geology
Abstract: International audience; The VIRTIS (Visual IR Thermal Imaging Spectrometer) experiment has been one of the most successful experiments built in Europe for Planetary Exploration. VIRTIS, developed in cooperation among Italy, France and Germany, has been already selected as a key experiment for 3 planetary missions: the ESA-Rosetta and Venus Express and NASA-Dawn. VIRTIS on board Rosetta and Venus Express are already producing high quality data: as far as Rosetta is concerned, the Earth-Moon system has been successfully observed during the Earth Swing-By manouver (March 2005) and furthermore, VIRTIS will collect data when Rosetta flies by Mars in February 2007 at a distance of about 200 kilometres from the planet. Data from the Rosetta mission will result in a comparison – using the same combination of sophisticated experiments – of targets that are poorly differentiated and are representative of the composition of different environment of the primordial solar system. Comets and asteroids, in fact, are in close relationship with the planetesimals, which formed from the solar nebula 4.6 billion years ago. The Rosetta mission payload is designed to obtain this information combining in situ analysis of comet material, obtained by the small lander Philae, and by a long lasting and detailed remote sensing of the comet, obtained by instrument on board the orbiting Spacecraft. The combination of remote sensing and in situ measurements will increase the scientific return of the mission. In fact, the “in situ” measurements will provide “ground-truth” for the remote sensing information, and, in turn, the locally collected data will be interpreted in the appropriate context provided by the remote sensing investigation. VIRTIS is part of the scientific payload of the Rosetta Orbiter and will detect and characterise the evolution of specific signatures – such as the typical spectral bands of minerals and molecules – arising from surface components and from materials dispersed in the coma. The identification of spectral features is a primary goal of the Rosetta mission as it will allow identification of the nature of the main constituent of the comets. Moreover, the surface thermal evolution during comet approach to sun will be also studied.
Published: 2007
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Journal

Database

Publisher

132 results on '"J Crovisier"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources