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148 results on '"Laboratoire Universitaire d'Astrophysique de Nice (LUAN)"'

1. Stochastic resonance: another way to retrieve subthreshold digital data

Author

Jean-Christophe Comte, Saverio Morfu, Laboratoire Electronique, Informatique et Image [UMR6306] (Le2i), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Electronique, Informatique et Image ( Le2i ), Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Universitaire d'Astrophysique de Nice ( LUAN ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Hippolyte Fizeau (FIZEAU), 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, and 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)

Subjects
[ INFO.INFO-TS ] Computer Science [cs]/Signal and Image Processing, Stochastic resonance, [ PHYS.COND.CM-DS-NN ] Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], Acoustics, Digital data, General Physics and Astronomy, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, 01 natural sciences, [ PHYS.PHYS.PHYS-DATA-AN ] Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an], 010305 fluids & plasmas, nonlinear dynamics, Optics, [NLIN.NLIN-PS]Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS], [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, 0103 physical sciences, Modulation (music), [ NLIN.NLIN-PS ] Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS], stochastic resonance, [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], 010306 general physics, Physics, Frequency-shift keying, business.industry, Subthreshold conduction, White noise, [ SPI.TRON ] Engineering Sciences [physics]/Electronics, [SPI.TRON]Engineering Sciences [physics]/Electronics, 02.50.-r, 05.40.-a, Nonlinear system, Amplitude, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an]
Abstract

International audience; A new type of electronic receiver based on stochastic resonance properties is proposed to retrieve subthreshold modulated (or not) digital signals. In order to check the receiver performances, we investigated different kinds of modulations. Considering both uniform and Gaussian white noise, a total restoration of the emitted data is achieved for an unmodulated or amplitude modulated (AM) signals, while an almost total restoration is reached using a frequency shift keying (FSK) modulation. These experimental results confirm the great interest of stochastic resonance in the signal transmission field.

Published
2003

2. Influence of a 6-week arm exercise program on walking ability and health status after hip arthroplasty: a 1-year follow-up pilot study

Author

Benoit Dugué, Anne-Françoise Faillenet-Maire, Bernard Parratte, Nicolas Tordi, Céline Grange, Juhani Smolander, Jean-Denis Rouillon, Jérôme Maire, Laboratoire Universitaire d'Astrophysique de Nice ( LUAN ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Marqueurs pronostiques et facteurs de régulations des pathologies cardiaques et vasculaires - UFC ( PCVP / CARDIO ), Université Bourgogne Franche-Comté ( UBFC ) -Université de Franche-Comté ( UFC ) -Centre Hospitalier Régional Universitaire [Besançon] ( CHRU Besançon ), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Marqueurs pronostiques et facteurs de régulations des pathologies cardiaques et vasculaires - UFC ( EA 3920) (PCVP / CARDIO), Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)

Subjects
Male, 030506 rehabilitation, Time Factors, medicine.medical_treatment, Arthroplasty, Replacement, Hip, Health Status, MESH : Aged, 1 year follow up, Pilot Projects, MESH : Walking, Osteoarthritis, Walking, MESH : Arthroplasty, Replacement, Hip, law.invention, 0302 clinical medicine, Arm exercise, Randomized controlled trial, law, Medicine, MESH: Arthroplasty, Replacement, Hip, MESH : Female, MESH: Arm, MESH: Health Status, MESH: Aged, Rehabilitation, MESH : Pilot Projects, MESH: Follow-Up Studies, Exercise Therapy, Arm, Female, 0305 other medical science, MESH : Time Factors, musculoskeletal diseases, medicine.medical_specialty, WOMAC, MESH : Male, MESH : Exercise Therapy, MESH : Arm, 03 medical and health sciences, Physical medicine and rehabilitation, [ SDV.MHEP ] Life Sciences [q-bio]/Human health and pathology, Aerobic exercise, Humans, MESH: Walking, MESH: Exercise Therapy, MESH : Health Status, Aged, MESH: Humans, business.industry, MESH: Time Factors, MESH : Humans, MESH : Follow-Up Studies, 030229 sport sciences, medicine.disease, MESH: Pilot Projects, Arthroplasty, MESH: Male, Physical therapy, business, MESH: Female, human activities, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, Follow-Up Studies
Abstract

International audience; The influence of an upper-limb interval-training program after total hip arthroplasty (THA) in elderly patients was studied during a 1 yr follow-up on health status and walking ability. After surgery, 14 patients were randomly assigned to the control group that started a 6 wk general rehabilitation program or the training group that combined it with an interval exercise program on an arm ergometer. A Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index was completed 1 mo before and 2 mo and 1 yr after surgery. A 6 min walking test was performed at 2 mo and 1 yr after surgery. The training group covered a significantly longer distance than the control group in the 6 min walk test and obtained significantly lower WOMAC scores both at 2 mo and 1 yr after surgery. However, both groups significantly improved in WOMAC and in their performance during the survey. Endurance-type upper-body aerobic training in a rehabilitation program might be important after THA.

Published
2009

3. HiRISE - High-Resolution Imaging and Spectroscopy Explorer - ultrahigh resolution, interferometric and external occulting coronagraphic science

Author

Erdélyi, Robertus, Damé, Luc, Fludra, Andrzej, Mathioudakis, Mihalis, Amari, T., Belucz, B., Berrilli, F., Bogachev, S., Bolsée, D., Bothmer, V., Brun, S., Dewitte, S., de Wit, T. Dudok, Faurobert, M., Gizon, L., Gyenge, N., Korsós, M. B., Labrosse, Nicolas, Matthews, S., Meftah, M., Morgan, H., Pallé, P., Rochus, P., Rozanov, E., Schmieder, B., Tsinganos, K., Verwichte, E., Zharkov, S., Zuccarello, F., Wimmer-Schweingruber, R., Solar Physics and Space Plasma Research Centre, School of Mathematics and Statistics [Sheffield] (SoMaS), University of Sheffield [Sheffield]-University of Sheffield [Sheffield], Eötvös Loránd University (ELTE), Hungarian Solar Physics Foundation (HSPF), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Centre de Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Roma Tor Vergata [Roma], P. N. Lebedev Physical Institute of the Russian Academy of Sciences [Moscow] (LPI RAS), Russian Academy of Sciences [Moscow] (RAS), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Georg-August-University = Georg-August-Universität Göttingen, Département d'astrophysique, Géophysique et Océanographie (AGO), Université de Liège, Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute (IRM), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), 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 d'Orléans (UO)-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)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 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)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Aberystwyth University, SUPA School of Physics and Astronomy [Glasgow], University of Glasgow, Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), STRATO - LATMOS, Instituto de Astrofisica de Canarias (IAC), Centre Spatial de Liège (CSL), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), National and Kapodistrian University of Athens (NKUA), University of Warwick [Coventry], University of Hull [United Kingdom], Dipartimento di Fisica e Astronomia [Catania], Università degli studi di Catania = University of Catania (Unict), Christian-Albrechts-Universität zu Kiel (CAU), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Max-Planck-Institut für Sonnensystemforschung (MPS)

Subjects
Solar atmosphere, Astronomy & Astrophysics, CORONA, Solar physics mission, LIMITS, LEAKAGE, Photosphere, SDG 13 - Climate Action, Ultra-high resolution, Astrophysics::Solar and Stellar Astrophysics, Interferometry, Coronagraph, Chromosphere, Corona, QC, QB, Science & Technology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics::Instrumentation and Methods for Astrophysics, MAGNETIC-FIELD, SUN, Astronomy and Astrophysics, IRRADIANCE, VARIABILITY, Space and Planetary Science, OUTFLOWS, Physics::Space Physics, Physical Sciences, ALFVEN WAVES, Astrophysics::Earth and Planetary Astrophysics, Settore FIS/06 - Fisica per il Sistema Terra e Il Mezzo Circumterrestre, SOLAR DIAMETER
Abstract

Recent solar physics missions have shown the definite role of waves and magnetic fields deep in the inner corona, at the chromosphere-corona interface, where dramatic and physically dominant changes occur. HiRISE (High Resolution Imaging and Spectroscopy Explorer), the ambitious new generation ultra-high resolution, interferometric, and coronagraphic, solar physics mission, proposed in response to the ESA Voyage 2050 Call, would address these issues and provide the best-ever and most complete solar observatory, capable of ultra-high spatial, spectral, and temporal resolution observations of the solar atmosphere, from the photosphere to the corona, and of new insights of the solar interior from the core to the photosphere. HiRISE, at the L1 Lagrangian point, would provide meter class FUV imaging and spectro-imaging, EUV and XUV imaging and spectroscopy, magnetic fields measurements, and ambitious and comprehensive coronagraphy by a remote external occulter (two satellites formation flying 375 m apart, with a coronagraph on a chaser satellite). This major and state-of-the-art payload would allow us to characterize temperatures, densities, and velocities in the solar upper chromosphere, transition zone, and inner corona with, in particular, 2D very high resolution multi-spectral imaging-spectroscopy, and, direct coronal magnetic field measurement, thus providing a unique set of tools to understand the structure and onset of coronal heating. HiRISE’s objectives are natural complements to the Parker Solar Probe and Solar Orbiter-type missions. We present the science case for HiRISE which will address: i) the fine structure of the chromosphere-corona interface by 2D spectroscopy in FUV at very high resolution; ii) coronal heating roots in the inner corona by ambitious externally-occulted coronagraphy; iii) resolved and global helioseismology thanks to continuity and stability of observing at the L1 Lagrange point; and iv) solar variability and space climate with, in addition, a global comprehensive view of UV variability.

Published
2022

4. Evolution of the Habitable Zone and Search for Life Around Red Giant Stars, Part I: Interest of the Study

Author

Richard K. Barry, J.-L. Menut, J. Rajagopal, Bruno Lopez, Adrian Belu, Jodi Schneider, William C. Danchi, Laboratoire Gemini ( LG ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), NASA Goddard Space Flight Center ( GSFC ), Department of Astronomy [College Park], University of Maryland [College Park], Observatoire de Paris - Site de Meudon ( OBSPM ), Observatoire de Paris-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Universitaire d'Astrophysique de Nice ( LUAN ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Physics and Astronomy [Baltimore], Johns Hopkins University ( JHU ), Laboratoire Gemini (LG), 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)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), NASA Goddard Space Flight Center (GSFC), University of Maryland System-University of Maryland System, Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), and Johns Hopkins University (JHU)

Subjects
Physics, 010504 meteorology & atmospheric sciences, Planetary habitability, Kepler-69c, Astronomy, Neocatastrophism, Astronomy and Astrophysics, 01 natural sciences, Habitability of orange dwarf systems, Astrobiology, Earth analog, Kepler-47, Eccentric Jupiter, 13. Climate action, Space and Planetary Science, Galactic habitable zone, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

International audience; We discuss the evolution of the habitable zone around low mass and intermediate mass stars as they evolve off the main sequence. This work shows that this class of stars should be included in the search for life because if planets could be found in their habitable zones, they will allow to test different hypothesis concerning the conditions of life formation. For instance if these planets show traces for life, it is possible to empirically determine a lower limit to the timescale for the formation of life. This time scale is not well determined from the Earth's study, as life formation initially occurred during a period of heavy bombardment from comets and asteroids during the formation of the solar system. We will summarize (to the best of our knowledge) some of the recent results concerning the early signs of life on Earth. We will present some of our work in progress in which we evaluate the effects of stellar evolution on the habitable zone changes.

Published
2005

5. Evolution of the Habitable Zone and Search for Life Around Giant Stars Part II: Feasibility with Darwin/TPF

Author

William C. Danchi, Jodi Schneider, Richard K. Barry, A. R. Belu, Bruno Lopez, J. Rajagopal, L. J. Richardson, NASA Goddard Space Flight Center (GSFC), Laboratoire Gemini (LG), 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)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Baltimore], Johns Hopkins University (JHU), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, NASA Goddard Space Flight Center ( GSFC ), Laboratoire Gemini ( LG ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Observatoire de Paris - Site de Meudon ( OBSPM ), Observatoire de Paris-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Universitaire d'Astrophysique de Nice ( LUAN ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), and Johns Hopkins University ( JHU )

Subjects
Physics, 010504 meteorology & atmospheric sciences, Rare Earth hypothesis, Astronomy, Astronomy and Astrophysics, 01 natural sciences, Habitability of orange dwarf systems, Astrobiology, Earth analog, Kepler-47, Eccentric Jupiter, Space and Planetary Science, Galactic habitable zone, 0103 physical sciences, Darwin (spacecraft), Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Circumstellar habitable zone, 0105 earth and related environmental sciences
Abstract

International audience; We discuss the evolution of the habitable zone around low mass and intermediate mass stars as they evolve off the main sequence. This work shows that this new class of stars should be included in the search for life because if planets could be found in their habitable zones, and these planets showed evidence for life, it is possible to empirically determine a lower limit to the timescale for the formation of life. This time scale is not well determined from the study of the Earth (or planets around main sequence stars), as life formation initially occurred during a period of heavy bombardment from comets and asteroids during the formation of the solar system. Our initial research was recently published (Lopez, Schneider, & Danchi 2005). We will describe our work in progress, in which we perform calculations and simulations aiming to demonstrate the potential of TPF and Darwin for the search and characterization of planets around evolved stars.

Published
2005

6. Analog simulation of neural information propagation using an electrical FitzHugh-Nagumo lattice

Author

Patrick Marquié, Saverio Morfu, Jean-Christophe Comte, Laboratoire Electronique, Informatique et Image ( Le2i ), Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Universitaire d'Astrophysique de Nice ( LUAN ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Electronique, Informatique et Image [UMR6306] (Le2i), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (... - 2019) (UNS), and 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)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Information propagation, Quantitative Biology::Neurons and Cognition, General Mathematics, Applied Mathematics, Quantitative Biology::Tissues and Organs, General Physics and Astronomy, Statistical and Nonlinear Physics, Fitzhugh nagumo, 01 natural sciences, 010305 fluids & plasmas, Pulse propagation, Nonlinear system, [NLIN.NLIN-PS]Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS], Lattice (order), 0103 physical sciences, [ NLIN.NLIN-PS ] Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS], Statistical physics, FitzHugh–Nagumo model, 010306 general physics, Nonlinear Sciences::Pattern Formation and Solitons
Abstract

International audience; A nonlinear electrical lattice modelling neural information propagation is presented. It is shown that our system is an analog simulator of the FitzHugh-Nagumo equations, and hence supports pulse propagation with the appropriate properties.

Published
2004

7. Propagation failure reduction in a Nagumo chain

Author

Saverio Morfu, Laboratoire Electronique, Informatique et Image [UMR6306] (Le2i), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Electronique, Informatique et Image ( Le2i ), Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Universitaire d'Astrophysique de Nice ( LUAN ), Université Nice Sophia Antipolis ( UNS ), and Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Physics, Information propagation, propagation failure, neural network, Noise effects, [ PHYS.COND.CM-DS-NN ] Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], Mathematical analysis, General Physics and Astronomy, Perturbation (astronomy), noise enhanced propagation, 01 natural sciences, [ PHYS.PHYS.PHYS-DATA-AN ] Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an], 010305 fluids & plasmas, Nonlinear system, nonlinear dynamics, [NLIN.NLIN-PS]Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS], Nagumo, 05.40.Ca, 45.05.+x, 87.10.+e, Lattice (order), 0103 physical sciences, [ NLIN.NLIN-PS ] Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS], [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], 010306 general physics, Computer Science::Databases, [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an]
Abstract

International audience; We show numerically and theoretically that a Nagumo lattice initially in propagation failure conditions can sustain information propagation thanks to an additive perturbation. This effect can be extended to random perturbations where anappropriate amount of noise enhances propagation.

Published
2003

8. Evolution of exploding granules from coordinated observations by THEMIS, IRIS, SDO/HMI, and HINODE, and a simulation

Author

Kévin Dalmasse, R. Douet, B. Gelly, J. M. Malherbe, Th. Roudier, Z. Frank, Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, 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), Télescope héliographique pour l'étude du magnétisme et des instabilites solaires (THEMIS), Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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), and Université Nice Sophia Antipolis (1965 - 2019) (UNS)

Subjects
Physics, Photosphere, 010504 meteorology & atmospheric sciences, Granule (cell biology), FOS: Physical sciences, Sun: photosphere, Astronomy and Astrophysics, Radius, Astrophysics, Image segmentation, 01 natural sciences, law.invention, Sun: granulation, Telescope, Wavelength, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, law, 0103 physical sciences, Magnetohydrodynamics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Image resolution, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences
Abstract

Exploding granules constitute the strongest horizontal flows on the quiet Sun and contribute to the structure of the surface horizontal velocity fields which build the large-scale organization of the discrete magnetic field. In this work we explore exploding granule expansion through the observations of the ground-based THEMIS telescope, IRIS, SDO, and the Hinode space-borne instruments, and finally with the magnetohydrodynamics simulation. We evaluate the detection and the expansion of exploding granules at several wavelengths and at various spatial and temporal resolutions. To analyze the different temporal sequences, two methods of image segmentation are applied to select the granules. The first allows us to follow individually the exploding granules observed simultaneously by THEMIS, IRIS, and SDO. The second uses long time independent sequences from THEMIS, IRIS, SDO, Hinode, and a simulation. In the first method (called manual) the segmentation isolates the cell of the granules (bright granules and intergranular parts), while in the second method (called statistical) only the bright part of the granules are isolated. The results obtained with simultaneous or distinct temporal observations using the two methods of segmentation are in good agreement. The granule area evolves linearly with an expansion velocity that decreases with the radius. A rapid decrease in the velocity expansion in the first two minutes is observed. The detection and measurement of the dynamics of the explosive granules can be performed from ground- and space-based instruments. Our work reveals the usefulness of SDO data, with low spatial resolution, to study the dynamics of the exploding granules all over the solar surface, 28 pages,19 figures, published in Astronomy and Astrophysics

Published
2020

9. Divergences. Scale invariant Divergences. Applications to linear inverse problems. N.M.F. Blind deconvolution

Author

Lantéri, Henri, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), and Université de Nice - Sophia Antipolis

Subjects
[MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC]
Abstract

This book deals with functions allowing to express the dissimilarity (discrepancy) between two data fields or "divergence functions" with the aim of applications to linear inverse problems.\\Most of the divergences found in the litterature are used in the field of information theory to quantify the difference between two probability density functions, that is between positive data whose sum is equal to one. In such context, they take a simplified form that is not adapted to the problems considered here, in which the data fields are non-negative but with a sum not necessarily equal to one.\\In a systematic way, we reconsider the classical divergences and we give their forms adapted to inverse problems.\\To this end, we will recall the methods allowing to build such divergences, and propose some generalizations.\\The resolution of inverse problems implies systematically the minimisation of a divergence between physical measurements and a model depending of the unknown parameters.\\In the context image reconstruction, the model is generally linear and the constraints that must be taken into account are the non-negativity as well as (if necessary) the sum constraint of the unknown parameters.\\To take into account in a simple way the sum constraint, we introduce the class of scale invariant or affine invariant divergences. Such divergences remains unchanged when the model parameters are multiplied by a constant positive factor. We show the general properties of the invariance factors, and we give some interesting characteristics of such divergences.An extension of such divergences allows to obtain the property of invariance with respect to both the arguments of the divergences; this characteristic can be used to introduce the smoothness regularization of inverse problems, that is a regularisation in the sense of Tikhonov.We then develop in a last step, minimisation methods of the divergences subject to non-negativity and sum constraints on the solution components. These methods are founded on the Karush-Kuhn-Tucker conditions that must be fulfilled at the optimum. The Tikhonov regularization is considered in these methods.Chapter 11 associated with Appendix 9 deal with the application to the NMF, while Chapter 12 is dedicated to the Blind Deconvolution problem.In these two chapters, the interest of the scale invariant divergences is highlighted.

Published
2020

10. Observing Planetary Systems in the Making

Author

Andrea Isella, Luca Ricci, Sean Andrews, Clément Baruteau, Jean-Philippe Berger, Edwin Bergin, Til Birnstiel, Brendan Bowler, Crystal Brogan, Carlos Carrasco Gonzalez, Claire Chandler, Thayne Currie, Jeffrey Cuzzi, Angelo, Gennaro D., Ruobing Dong, Gaspard Duchene, Anne Dutrey, Barbara Ercolano, Catherine Espaillat, Paul Estrada, Mario Flock, Andras Gaspar, Greene, Thomas P., Jane Huang, Hannah Jang-Condell, Christopher Johns-Krull, Grant Kennedy, Serena Kim, J., Florian Kirchschlager, Stefan Kraus, Sebastiaan Krijt, Hui Li, Wladimir Lyra, Bruce Macintosh, John Monnier, Karin Oberg, Ilaria Pascucci, Laura Perez, Romain Petrov, Paola Pinilla, Stephen Ridgway, Keivan Stassun, Theo ten Brummelaar, Leonardo Testi, Turner, Neal J., Gerard van Belle, Nienke van Der Marel, Alycia Weinberger, Jacob White, Jonathan Williams, David Wilner, Alwyn Wootten, Ya-Lin Wu, Andrew Youdin, Ke Zhang, Zhaohuan Zhu, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, McDonald Observatory, University of Texas at Austin [Austin], NASA Ames Research Center (ARC), Steward Observatory, University of Arizona, 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]), AMOR 2019, 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 de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Search for Extraterrestrial Intelligence Institute (SETI), Max-Planck-Institut für Radioastronomie (MPIFR), Department of Astrophysics, American Museum of Natural History (AMNH), Umeå University, Molecular Genetics Unit, Instituto de Salud Carlos III [Madrid] (ISC)-Carretera Pozuelo - Callejero de Majadahonda- Instituto de Investigación en Enfermedades Raras (IIER), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 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)-Centre National de la Recherche Scientifique (CNRS), National Optical Astronomy Observatory (NOAO), Center for High Angular Resolution Astronomy (CHARA), Georgia State University, University System of Georgia (USG)-University System of Georgia (USG), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), School of Mathematical and Statistical Sciences (Arizona, Tempe), Arizona State University [Tempe] (ASU), Centre Européen de Réalité Virtuelle (CERV), École Nationale d'Ingénieurs de Brest (ENIB), Flathead Lake Biological Station, University of Montana, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Smithsonian Institution-Harvard University [Cambridge], American Museum of Natural History, Université Nice Sophia Antipolis (... - 2019) (UNS), Rice University [Houston], Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Harvard University [Cambridge]-Smithsonian Institution, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Salud Carlos III (ISC)-Carretera Pozuelo - Callejero de Majadahonda- Instituto de Investigación en Enfermedades Raras (IIER), and Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Computer Science::Computer Vision and Pattern Recognition, Physics::Space Physics, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Astrophysics::Earth and Planetary Astrophysics, GeneralLiterature_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract

International audience; We discuss science cases to support the development of sub-au imaging capabilities to image forming planets in the terrestrial region of nearby proto-planetary disks.

Published
2019

11. Direct Imaging of the HD 35841 Debris Disk: A Polarized Dust Ring from Gemini Planet Imager and an Outer Halo from HST/STIS

Author

Bruce Macintosh, Juan Sebastián Bruzzone, Abhijith Rajan, Julien Rameau, Quinn Konopacky, Jérôme Maire, Pauline Arriaga, Bin Ren, Lisa Poyneer, Inseok Song, Rémi Soummer, Sandrine Thomas, Adam C. Schneider, Rebecca Oppenheimer, Christine Chen, Paul Kalas, James R. Graham, Alexandra Z. Greenbaum, David Palmer, J. Kent Wallace, James E. Larkin, Jason J. Wang, Sloane J. Wiktorowicz, Robert J. De Rosa, Eugene Chiang, Gaspard Duchêne, Thomas M. Esposito, Stephen J. Goodsell, Laurent Pueyo, Schuyler Wolff, Joanna Bulger, Marshall D. Perrin, Eric L. Nielsen, Patrick Ingraham, Pascale Hibon, Jeffrey Chilcote, Vanessa P. Bailey, Tara Cotten, Johan Mazoyer, Stanimir Metchev, Dominic M. Ryan, S. Mark Ammons, Kimberly Ward-Duong, Dmitry Savransky, René Doyon, Li-Wei Hung, Maxwell A. Millar-Blanchaer, Franck Marchis, Jennifer Patience, Malena Rice, Elodie Choquet, Travis Barman, Michael P. Fitzgerald, Christian Marois, Fredrik T. Rantakyrö, Anand Sivaramakrishnan, Megan Ansdell, Katherine B. Follette, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), 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]), Department of Mathematics [Berkeley], University of California [Berkeley], University of California-University of California, Search for Extraterrestrial Intelligence Institute (SETI), Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Johns Hopkins University (JHU), Space Telescope Science Institute (STSci), Department of Physics and Astronomy [UCLA, Los Angeles], University of California [Los Angeles] (UCLA), Department of Earth and Planetary Science [UC Berkeley] (EPS), Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), Stanford University, Physics and Astronomy Department, Amherst College, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Arizona State University [Tempe] (ASU), 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), California Institute of Technology (CALTECH)-NASA, Stanford University [Stanford], and Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, 01 natural sciences, circumstellar matter, 010305 fluids & plasmas, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Gemini Planet Imager, Surface brightness, planetary systems [infrared], 010303 astronomy & astrophysics, individual [stars], Astrophysics::Galaxy Astrophysics, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Debris disk, Scattering, high angular resolution [techniques], Astronomy and Astrophysics, Planetary system, Radiation pressure, 13. Climate action, Space and Planetary Science, astro-ph.EP, Spectral energy distribution, Halo, Astrophysics::Earth and Planetary Astrophysics, Astronomical and Space Sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present new high resolution imaging of a light-scattering dust ring and halo around the young star HD 35841. Using spectroscopic and polarimetric data from the Gemini Planet Imager in H-band (1.6 microns), we detect the highly inclined (i=85 deg) ring of debris down to a projected separation of ~12 au (~0.12") for the first time. Optical imaging from HST/STIS shows a smooth dust halo extending outward from the ring to >140 au (>1.4"). We measure the ring's scattering phase function and polarization fraction over scattering angles of 22-125 deg, showing a preference for forward scattering and a polarization fraction that peaks at ~30% near the ansae. Modeling of the scattered-light disk indicates that the ring spans radii of ~60-220 au, has a vertical thickness similar to that of other resolved dust rings, and contains grains as small as 1.5 microns in diameter. These models also suggest the grains have a low porosity, are more likely to consist of carbon than astrosilicates, and contain significant water ice. The halo has a surface brightness profile consistent with that expected from grains pushed by radiation pressure from the main ring onto highly eccentric but still bound orbits. We also briefly investigate arrangements of a possible inner disk component implied by our spectral energy distribution models, and speculate about the limitations of Mie theory for doing detailed analyses of debris disk dust populations., Accepted to AJ. 22 pages, 11 figures, 3 tables

Published
2018

12. VLTI-AMBER velocity-resolved aperture-synthesis imaging of Eta Carinae with a spectral resolution of 12000. Studies of the primary star wind and innermost wind-wind collision

Author

R. Grellmann, Dieter Schertl, Michael F. Corcoran, Sridharan Rengaswamy, Gerd Weigelt, T. I. Madura, D. J. Hillier, Th. Rivinius, F. Patru, M. Teodoro, Markus Schöller, K. Ohnaka, M. Heininger, S. Guieu, A. Mérand, R. G. Petrov, T. R. Gull, Nicola Clementel, Karl-Heinz Hofmann, A. F. J. Moffat, Stefan Kraus, F. Millour, W. J. de Wit, J. H. Groh, Andrea Mehner, Noel D. Richardson, C. A. Hummel, Augusto Damineli, Markus Wittkowski, Max-Planck-Institut für Radioastronomie (MPIFR), 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]), Department of Physics and Astronomy [Pittsburgh], University of Pittsburgh (PITT), Pennsylvania Commonwealth System of Higher Education (PCSHE)-Pennsylvania Commonwealth System of Higher Education (PCSHE), European Southern Observatory (ESO), Joseph Louis LAGRANGE (LAGRANGE), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Center for High Angular Resolution Astronomy (CHARA), Georgia State University, University System of Georgia (USG)-University System of Georgia (USG), Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010308 nuclear & particles physics, Aperture synthesis, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Position angle, 01 natural sciences, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, Astrophysics::Earth and Planetary Astrophysics, Spectral resolution, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Line (formation)
Abstract

International audience; Context. The mass loss from massive stars is not understood well. Eta Car is a unique object for studying the massive stellar wind during the LBV phase. It is also an eccentric binary with a period of 5.54 yr. The nature of both stars is uncertain, although we know from X-ray studies that there is a wind-wind collision whose properties change with orbital phase. Methods. Observations of Eta Car were carried out with the ESO VLTI and the AMBER instrument between approximately five and seven months before the August 2014 periastron passage. Velocity-resolved aperture-synthesis images were reconstructed from the spectrally dispersed interferograms. Interferometric studies can provide information on the binary orbit, the primary wind, and the wind collision. Results. We present velocity-resolved aperture-synthesis images reconstructed in more than 100 different spectral channels distributed across the Br Gamma 2.166 micrometer emission line. The intensity distribution of the images strongly depends on wavelength. At wavelengths corresponding to radial velocities of approximately -140 to -376 km/s measured relative to line center, the intensity distribution has a fan-shaped structure. At the velocity of -277 km/s, the position angle of the symmetry axis of the fan is ~ 126 degree. The fan-shaped structure extends approximately 8.0 mas (~ 18.8 au) to the southeast and 5.8 mas (~ 13.6 au) to the northwest, measured along the symmetry axis at the 16% intensity contour. The shape of the intensity distributions suggests that the obtained images are the first direct images of the innermost wind-wind collision zone. Therefore, the observations provide velocity-dependent image structures that can be used to test three-dimensional hydrodynamical, radiative transfer models of the massive interacting winds of Eta Car.

Published
2016
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13. Dome C boundary layer and seeing peculiarities

Author

Eric Aristidi, Eric Fossat, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (... - 2019) (UNS), and 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)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010504 meteorology & atmospheric sciences, Meteorology, Turbulence, Astrophysics::Instrumentation and Methods for Astrophysics, General Engineering, Astronomy and Astrophysics, Inversion (meteorology), Geophysics, 01 natural sciences, Physics::Fluid Dynamics, Boundary layer, Space and Planetary Science, 0103 physical sciences, Surface layer, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

International audience; This paper presents some statistical information about the Concordia turbulent surface inversion layer, regarding height and turbulent energy, its contribution to the peculiar local seeing, and the free atmosphere seeing encountered just above this surface layer.

Published
2009

14. Implications of Turbulence Optical Parameters on HAR Techniques at Dome C

Author

F. Martin, Eric Aristidi, Eric Fossat, A. Agabi, J. Maire, Aziz Ziad, Julien Borgnino, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), 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), and Laboratoire Hippolyte Fizeau (FIZEAU)

Subjects
Wavefront, Physics, Coherence time, Meteorology, Scale (ratio), business.industry, Turbulence, Astrophysics::Instrumentation and Methods for Astrophysics, General Engineering, Astronomy and Astrophysics, 01 natural sciences, 010309 optics, Dome (geology), Space and Planetary Science, 0103 physical sciences, Atmospheric turbulence, Aerospace engineering, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], business, Adaptive optics, 010303 astronomy & astrophysics
Abstract

The HAR observing methods such as Adaptive Optics and Interferometery, require a better understanding of the behavior of the perturbed wavefronts, more exactly a better knowledge of the atmospheric turbulence model in addition to the associate parameters. This is very crucial for modeling the HAR techniques and particularly for the evaluation of their performance. Indeed, it is well-known that the performance of an AO system depends upon the seeing conditions, the outer scale, the isoplanatic angle and the coherence time. A review of the site-testing instruments deployed at Dome C will be given, their pertinence and their implications on HAR techniques will be discussed comparatively to the Paranal site.

Published
2009

15. Speckle observations with PISCO in Merate – V. Astrometric measurements of visual binaries in 2006

Author

Mauro Ghigo, M. Sala, Jean-Louis Prieur, Eric Aristidi, Luigi Pansecchi, Marco Scardia, L. Koechlin, Robert Argyle, Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 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)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, and Université Nice Sophia Antipolis (... - 2019) (UNS)

Subjects
Physics, binaries: close, 010308 nuclear & particles physics, Astronomy, stars: individual: ADS 277, Astronomy and Astrophysics, Astrometry, Astrophysics, Position angle, binaries: visual, 01 natural sciences, law.invention, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Telescope, Speckle pattern, Interferometry, techniques: interferometric, Space and Planetary Science, Observatory, law, 0103 physical sciences, astrometry, Speckle imaging, 010303 astronomy & astrophysics, Coronagraph
Abstract

International audience; We present relative astrometric measurements of visual binaries made during the first semester of 2006, with the Pupil Interferometry Speckle camera and COronagraph at the 102-cm Zeiss telescope of the Brera Astronomical Observatory, in Merate. Our sample contains orbital couples as well as binaries whose motion is still uncertain. We obtained 217 new measurements of 194 objects, with angular separations in the range 0.1-4.2arcsec, and an average accuracy of 0.01arcsec. The mean error on the position angles is 0.5°. About half of those angles could be determined without the usual 180° ambiguity by the application of triple-correlation techniques. We also present a revised orbit for ADS 277 for which the previously published orbit resulted in a large residual from our measurements.

Published
2008

16. Nighttime Optical Turbulence Vertical Structure above Dome C in Antarctica

Author

M. Azouit, H. Trinquet, Eric Aristidi, Jean Vernin, Abdelkrim Agabi, Eric Fossat, Laboratoire Hippolyte Fizeau (FIZEAU), 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), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), and Joseph Louis LAGRANGE (LAGRANGE)

Subjects
Turbulence, Astronomy and Astrophysics, Atmospheric sciences, 01 natural sciences, Wind speed, 010309 optics, Atmosphere, Dome (geology), Boundary layer, Microthermal, 13. Climate action, Space and Planetary Science, Middle latitudes, 0103 physical sciences, Potential temperature, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Geology
Abstract

International audience; During the austral winter 2005, the first astronomical site testing campaign were performed at Dome C, in Antarctica. Thirty-five meteorological balloons equipped with microthermal sensors were used to sense the vertical profile of the optical turbulence intensity above Dome C up to 20 km. All the profiles of the 2005 campaign are statistically analyzed. We provide the median profiles and the mean potential temperature, mean horizontal wind speed, and mean direction profiles for the three seasons covered by this campaign (autumn, winter, and beginning of the spring). The structure of the optical turbulence in the atmosphere above Dome C is analyzed and compared with the well-known median profiles of midlatitude sites. Of the whole optical turbulence, 80% lies within the first 33 m above the ground and 9% in the upper part of the boundary layer, between 33 m and 1 km above the ground. The remaining 11% are in the free atmosphere. This is an extreme situation when compared with “classical” midlatitude sites where the surface layer extends up to 200 m. This strong and thin surface layer is the result of the kinetic turbulent mixing of air combined with a strong potential temperature gradient. The site is characterized from the adaptive optics point of view. Seeing, isoplanatic angle, and coherence time are estimated for each considered seasons. A four-layer decomposition for each season is provided for adaptive optics simulations. For high angular astronomy, a telescope at Dome C needs to be elevated over this surface layer, or a specific GLAO needs to be designed. Combined with the unique possibility of performing continuous observation from Antarctica, scientific programs such as microlensing, pulsating stars, and asteroseismology become feasible.

Published
2008

17. Choosing Dome C, Antarctic Plateau as Future Astronomical Observatory

Author

M. Azouit, H. Trinquet, Marc Sarazin, A. Agabi, T. Sadibekova, Eric Fossat, C. Genthon, Eric Aristidi, Gerhard Krinner, Merieme Chadid, Jean Vernin, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), 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), Laboratoire Hippolyte Fizeau (FIZEAU), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), 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 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 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), European Southern Observatory (ESO), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Observatoire des Sciences de l'Univers de Grenoble (OSUG), and 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)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Meteorology, 010308 nuclear & particles physics, General Engineering, Astronomy and Astrophysics, 01 natural sciences, Dome (geology), Space and Planetary Science, Observatory, Climatology, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Antarctic plateau
Abstract

International audience; In this paper we present year-round climatological analysis made from radio-sounding measurements and ECMWF Data. And we end up with a generalized conclusion (scientific aspect) from statistical results of site-testing at Concordia concerning the feasibility of the future astronomical exploitation of Dome C.

Published
2007

18. Four new HgMn stars: HD 18104, HD 30085, HD 32867, and HD 53588

Author

M. Gebran, F. Royer, R. Monier, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 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)-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), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Nice Sophia Antipolis (... - 2019) (UNS)

Subjects
Physics, [PHYS]Physics [physics], 010308 nuclear & particles physics, FOS: Physical sciences, High resolution, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Spectral line, 3. Good health, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Hyperfine structure, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS
Abstract

We have detected four new HgMn stars, while monitoring a sample of apparently slowly rotating superficially normal bright late B and early A stars in the northern hemisphere. Important classification lines of Hg II and Mn II are found as conspicuous features in the high resolution SOPHIE spectra of these stars (R = 75000). Several lines of Hg II, Mn II and Fe II have been synthesized using model atmospheres and the spectrum synthesis code SYNSPEC48 including hyperfine structure of various isotopes when relevant. These synthetic spectra have been compared to high resolution high signal-to-noise observations of these stars in order to derive abundances of these key elements. The four stars are found to have distinct enhancements of Hg and Mn which show that these stars are not superficially normal B and A stars, but actually are new HgMn stars and should reclassified as such., Comment: 4 pages, 3 figures, accepted in A&A

Published
2015

19. L’environnement scientifique du jeune Albert Einstein

Author

Christian Bracco, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Systèmes de Référence Temps Espace (SYRTE), 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)-Centre National de la Recherche Scientifique (CNRS), and Université Nice Sophia Antipolis (1965 - 2019) (UNS)

Subjects
[PHYS]Physics [physics], General Medicine, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2015

20. The polar wind of the fast rotating Be star Achernar

Author

Pierre Kervella, A. Domiciano de Souza, Laboratoire Hippolyte Fizeau (FIZEAU), 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), 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 Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Gemini (LG), 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)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-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)

Subjects
Stellar mass, Be star, stars: emission-line, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], stars: rotation, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Photosphere, Infrared excess, 010308 nuclear & particles physics, Stellar rotation, techniques: high angular resolution, Astronomy, Be, Astronomy and Astrophysics, stars: individual: Achernar, Stars, Polar wind, techniques: interferometric, 13. Climate action, Space and Planetary Science, Polar, Astrophysics::Earth and Planetary Astrophysics, stars: mass-loss
Abstract

10 pages, 5 figures, accepté par A&A; International audience; Be stars show evidence of mass loss and circumstellar envelopes (CSE), from UV resonance lines, near-IR excesses and the presence of episodic hydrogen emission lines. The geometry of these envelopes is still uncertain, though it is often assumed that they are formed by a disk around the stellar equator and a hot polar wind. We probe the close environment of the fast rotating Be star Achernar at angular scales of a few mas in the infrared, in order to constrain the geometry of a possible polar CSE. We obtained long-baseline interferometric observations of Achernar with the VINCI/VLTI beam combiner in the $H$ and $K$ bands, using various telescope configurations and baseline lengths with a large azimuthal coverage. The observed visibility measurements along the polar direction are significantly lower than the visibility function of the photosphere of the star alone, in particular at low spatial frequencies. This points at the presence of an asymmetric diffuse CSE elongated along the polar direction of the star. We fit to our data a simple model consisting of two components: a 2D elliptical Gaussian superimposed on a uniform ellipse representing the distorted photosphere of the fast rotating star. We clearly detect a CSE elongated along the polar axis of the star, as well as the rotational flattening of the stellar photosphere. The relative near-IR flux measured for the CSE compared to the stellar photosphere is 5\%. Its angular dimensions are loosely constrained by the available data$2.7 \pm 1.3$ mas and $17.6 \pm 4.9$ mas. This CSE could be linked to free-free emission from the radiative pressure driven wind originating from the hot polar caps of the star.

Published
2006

21. Colour-differential interferometry for the observation of extrasolar planets

Author

Romain Petrov, Martin Vannier, Florentin Millour, Bruno Lopez, Laboratoire Hippolyte Fizeau (FIZEAU), 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), 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), European Southern Observatory (ESO), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Gemini (LG), 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)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Grenoble (LAOG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, spectroscopic -planetary systems, 010308 nuclear & particles physics, high angular resolution -techniques, Giant planet, Astronomy, Astronomy and Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Orbit, interferometric -techniques, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Astronomical interferometer, Astrophysics::Earth and Planetary Astrophysics, techniques, 010303 astronomy & astrophysics, Planetary mass, Astrophysics::Galaxy Astrophysics, Jupiter mass
Abstract

International audience; We present the high angular resolution technique of colour-differential interferometry for direct detection of extrasolar giant planets (EGPs). The measurement of differential phase with long-baseline ground-based interferometers in the near-infrared could allow the observation of several hot giant extrasolar planets in tight orbit around the nearby stars, and thus yield their low- or mid-resolution spectroscopy, complete orbital data set and mass. Estimates of potentially achievable signal-to-noise ratios are presented for a number of planets already discovered by indirect methods. The limits from the instrumental and atmospheric instability are discussed, and a subsequent observational strategy is proposed.

Published
2006

22. First Whole Atmosphere Nighttime Seeing Measurements at Dome C, Antarctica

Author

Eric Aristidi, Jean Vernin, M. Azouit, T. Sadibekova, Abdelkrim Agabi, Eric Fossat, Aziz Ziad, François Martin, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), and IPEV

Subjects
Physics, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 010308 nuclear & particles physics, Site testing, Astrophysics (astro-ph), Elevation, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Atmospheric sciences, 01 natural sciences, site testing, Atmosphere, High surface, Dome (geology), Space and Planetary Science, 0103 physical sciences, Polar, 010303 astronomy & astrophysics
Abstract

We report site testing results obtained in night-time during the polar autumn and winter at Dome C. These results were collected during the first Concordia winterover by A. Agabi. They are based upon seeing and isoplanatic angle monitoring, as well as in-situ balloon measurements 2 of the refractive index structure constant profiles Cn (h). Atmosphere is divided into two regions: (i) a 36 m high surface layer responsible of 87% of the turbulence and (ii) a very stable free atmosphere above with a median seeing of 0.36+-0.19 arcsec at an elevation of h = 30 m. The median seeing measured with a DIMM placed on top of a 8.5 m high tower is 1.3+-0.8 arcsec., accepted for publication in PASP (oct 2005)

Published
2006

23. Orbital elements of six visual binary stars

Author

Laurent Koechlin, Marco Scardia, Jean-Louis Prieur, Eric Aristidi, INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées (LATT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Université Nice Sophia Antipolis (1965 - 2019) (UNS)

Subjects
Physics, Orbital elements, visual binaries: orbits – stellar masses – dynamical parallaxes, Stars, Space and Planetary Science, Astronomy, Astronomy and Astrophysics, Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 10. No inequality, Visual binary
Abstract

International audience; Revised orbital elements of the visual binary stars STT 515, BU 4 AB, STF 183 AB, A 207, STT 43 and A 2413 are given.Dynamical parallaxes and total masses of the systems have been calculated.

Published
2001

24. AMBER: a near infrared focal instrument for the VLTI

Author

Michael Geng, Martin Vannier, G. Martinot-Lagarde, M. Dugué, Yves Rabbia, S. Rebattu, Djamel Mékarnia, T. Forveille, Bruno Lopez, Karl-Heinz Hofmann, Stephane Lagarde, Carlo Baffa, Gilles Duvert, Pascal Puget, Karine Rousselet-Perraut, Fabien Malbet, Albrecht Dreiss, Udo Beckmann, Andrea Richichi, Eric Aristidi, Romain Petrov, Frédéric Cassaing, Danielle LeContel, Markus Schoeller, Yves Bresson, S. Robbe-Dubois, A. Glentzlin, Alessandro Marconi, D. Kamm, Philippe Berio, Sandro Gennari, David Mouillet, François Reynaud, P. Antonelli, K. Agabi, Isabelle Tallon-Bosc, Piero Salinari, Jean-Louis Monin, Franco Lisi, G. Mars, Alain Chelli, Etienne LeCoarer, M. Sacchettini, Gerd Weigelt, Denis Mourard, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Grenoble (LAOG), 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), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Radioastronomie (MPIFR), Département Fresnel (FRESNEL), Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-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), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche en Communications Optiques et Microondes (IRCOM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Active galactic nucleus, Young stellar object, FOS: Physical sciences, General Physics and Astronomy, Astrophysics, 01 natural sciences, 7. Clean energy, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 010309 optics, Optics, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, optical interferometry, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, instrumentation, Physics, Very Large Telescope, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Spatial filter, business.industry, Astrophysics (astro-ph), Near-infrared spectroscopy, Astrophysics::Instrumentation and Methods for Astrophysics, Single-mode optical fiber, Astronomy, [CHIM.MATE]Chemical Sciences/Material chemistry, Exoplanet, astronomy, very large telescope, Interferometry, Astrophysics::Earth and Planetary Astrophysics, business, high angular resolution
Abstract

AMBER is the General User near-infrared focal instrument of the Very Large Telescope interferometer. Its specifications are based on three key programs on Young Stellar Objects, Active Galactic Nuclei central regions, masses and spectra of hot Extra Solar Planets. It has an imaging capacity because it combines up to three beams and very high accuracy measurement are expected from the spatial filtering of beams by single mode fibers and the comparison of measurements made simultaneously in different spectral channels., 10 pages

Published
2001

25. Speckle Observations of Double Stars with PISCO at Pic du Midi: Measurements in 1998

Author

Marco Scardia, Eric Aristidi, Laurent Koechlin, Jean-Louis Prieur, INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (... - 2019) (UNS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées

Subjects
Physics, 010504 meteorology & atmospheric sciences, MIDI, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Angular distance, Astronomy, Astronomy and Astrophysics, Astrophysics, Astrometry, computer.file_format, 01 natural sciences, Speckle pattern, Stars, Space and Planetary Science, 0103 physical sciences, Binary star, 10. No inequality, 010303 astronomy & astrophysics, computer, 0105 earth and related environmental sciences
Abstract

We present astrometric measurements of binary stars based on speckle observations of 164 independent sequences of observations (~104 frames each) made with the PISCO speckle camera at Pic du Midi. These measurements concern 147 objects, of which 134 were found to be double with a separation in the range 01-10. These objects were mainly selected among grade 3 orbits to improve the accuracy of their orbits and to constrain their masses. We discovered the binarity of 59 Aql with an angular separation of 009 ± 001.

Published
2000

26. Error due to atmospheric turbulence effects on solar diameter measurements performed with an astrolabe

Author

Julien Borgnino, Lyes Lakhal, Christian Delmas, Maatouk Bouzaria, Francis Laclare, Abdanour Irbah, Centre de Recherche en Astronomie Astrophysique et Géophysique (CRAAG), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Département C.E.R.G.A (O.C.A), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)

Subjects
Physics, Wavefront, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Scale (ratio), Computer simulation, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, General Physics and Astronomy, Function (mathematics), Astrolabe, 010502 geochemistry & geophysics, 01 natural sciences, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Atmosphere, Optics, Fractal, Atmosphere of Earth, 13. Climate action, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing
Abstract

International audience; Diameter measurements performed with the solar astrolabe are affected by instrumental and atmospheric effects. The problem is to know how these effects contribute to the error on diameter measurements. Thus, a numerical simulation is developed to bring some responses to this problem. For this purpose, synthetic images of the Sun similar to the ones obtained by the instrument through the Earth atmosphere are simulated. A fractal model is used to generate randomly perturbed wavefronts and therefore optical response of the whole system, atmosphere and instrument. Many sequences of solar images are then simulated for various observation conditions (Fried's parameter r0, spatial coherence outer scale L0 and atmospheric characteristic times). They are used to define the time of contact of the direct and reflected solar images which is fundamental in the solar astrolabe experiment. It is then studied as a function of the observation conditions relatively to the experimental characteristics (exposure time).

Published
1999

27. Solar diameter measurements with Calern Observatory astrolabe and atmospheric turbulence effects

Author

Guy Merlin, Abdanour Irbah, Julien Borgnino, Francis Laclare, Centre de Recherche en Astronomie Astrophysique et Géophysique (CRAAG), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (... - 2019) (UNS), and 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)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 010504 meteorology & atmospheric sciences, Image quality, Astronomy and Astrophysics, Image processing, Astrolabe, 01 natural sciences, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Weighting, Data acquisition, Space and Planetary Science, Observatory, 0103 physical sciences, Atmospheric turbulence, Statistical analysis, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing
Abstract

International audience; In order to deduce significant astrophysical results from solar diameter measurements it is necessary to take an accurate account of instrumental and atmospheric effects. This paper presents a comparison between visual and charge coupled device (CCD) camera measurements performed by means of the Calern Observatory solar astrolabe during the last 4 years; this allows us to evaluate visual measurements done previously (1975-1989). Then, a study of atmospheric effects is developed. From CCD measurements, the image quality, expressed by Fried's seeing parameter, r0, is estimated and related to the errors occurring in solar diameter measurements. A statistical analysis gives about 0.26 arc sec (or 0.13 arc sec for the semi-diameter) as the lowest value that this error may reach at Calern Observatory. One conclusion of this work is that it is important in the future to have image quality observations, obtained using a dedicated monitor, in order to evaluate and classify the measurements. A survey of the seeing might so lead to improve the precision of the results by weighting each diameter estimation and eventually to schedule the observations.

Published
1994

28. Restauration des cubes hyperspectraux du spectro-imageur MUSE

Author

Bourguignon, Sébastien, Carfantan, Hervé, Mary, David, Slezak, Eric, Ferrari, Andrea, 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), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), 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), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
[INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience; Nous envisageons la restauration d'observations en imagerie hyperspectrale de champs profonds de l'univers pour le projet instrumental MUSE. En raison de la taille massive des données et du fort niveau de bruit, le problème global de restauration demande à la fois une réduction de dimension et la prise en compte d'informations a priori pertinentes. Des contraintes de parcimonie spectrale sont introduites, permettant de prendre en compte ces deux aspects. Le problème tri-dimensionnel est alors contraint dans un espace spectral de dimension réduite et la déconvolution est réalisée avec un a priori spectralement fort et spatialement peu contraignant. Des simulations attestent de l'intérêt de cette approche conjointe spatiale et spectrale par rapport à une reconstruction individuelle de chaque spectre. En particulier, un exemple est présenté, où deux sources ponctuelles proches et spatialement convoluées sont efficacement restaurées et leurs spectres démélangés.; We consider the restoration of extragalactic deep field hyperspectral imaging data in the context of the forthcoming MUSE instrument. Because of the high quantity of data and of the strong noise level, such restoration problem requires a dimension reduction operation and the incorporation of appropriate prior information. Both points are tackled in this paper by means of sparsity contraints in the spectral domain. The global three-dimensional problem is then constrained to a spectral subspace with lower dimension and deconvolution is performed with strong spectral prior information, and with almost no constraint on the spatial structure of the solution. Simulation results reveal the efficiency of this joint spatial and spectral approach, compared with the individual restoration of each spectrum. In particular, an example with two closely spaced and spatially convolved point sources shows satisfactory restoration and spectral unmixing performance.

Published
2011

29. Techniques d'apprentissage non-linéaires en ligne avec contraintes de positivité

Author

Chen, Jie, Richard, Cédric, Honeine, Paul, Snoussi, Hichem, Lantéri, Henri, Theys, Céline, Laboratoire Modélisation et Sûreté des Systèmes (LM2S), Institut Charles Delaunay (ICD), Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Hippolyte Fizeau (FIZEAU), Université Nice Sophia Antipolis (1965 - 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, 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), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), and 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)

Subjects
régression, machine learning, [INFO.INFO-LG]Computer Science [cs]/Machine Learning [cs.LG], [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, positivité, adaptive filtering, non-linéaire, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], adaptatif, non-negativity, réseau de capteurs, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, apprentissage
Abstract

International audience; Cet article décrit une nouvelle classe d'algorithmes d'apprentissage non-linéaires en ligne avec contrainte de positivité sur la solution. Ceux-ci sont appliqués au problème d'identification distribuée d'un champ scalaire positif, par exemple de rayonnement thermique ou de concentration d'une espèce chimique, par un réseau de capteurs. La question du suivi de l'évolution de la grandeur physique surveillée au cours du temps est également considérée. Les algorithmes proposés sont testés sur des données synthétiques régies par des équations de diffusion. Ils démontrent une excellente capacité de suivi des évolutions du système, tout en affichant un coût calculatoire réduit.

Published
2010

30. The LUCAS experiment: Spectroscopy of Earthshine in Antarctica for detection of life

Author

Eric Aristidi, Luc Arnold, D. Petermann, Danielle Briot, Patrick Rocher, Jérôme Berthier, Jean Schneider, Stéphane Jacquemoud, A. Agabi, Zalpha Challita, E. Bondoux, C. Pouzenc, Observatoire de Paris - Site de Paris (OP), 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), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 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, 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), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), 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 de Lille-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), Observatoire Sirene, Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), 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), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), 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), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, and 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)

Subjects
Physics, 010504 meteorology & atmospheric sciences, General Engineering, Red edge, Astronomy, Astronomy and Astrophysics, Vegetation, 01 natural sciences, Exoplanet, Latitude, Astrobiology, Physics::Geophysics, Space and Planetary Science, 0103 physical sciences, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Spectroscopy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

International audience; So as to prepare future observations of terrestrial extrasolar planets liable to shelter life, we attempt to detect the life on the Earth seen as a dot. We use the Moon Earthshine, in which any place reflects the totality of the enlightened part of Earth facing the Moon. Observing from OHP and from ESO, we detected terrestrial chlorophyll in the near infrared, the so-called Vegetation Red Edge, and this detection is larger when forests are present than when an ocean is mainly visible from the Moon. Only if observations are made from a high latitude location, and at some moments in the year, Earthshine can be observed during a large part of the day. During these long observing windows, different “landscapes" are facing the Moon. So the Earthshine corresponding to various parts of our Earth could be studied. Preliminary testing observations have been made at Concordia since the first winterover campaign and the LUCAS experiment has been set up.

Published
2009

31. Studying the vertical extent of the ground layer turbulence using sonic-anemometers

Author

Eric Fossat, Tony Travouillon, D. Odoardi, F. Jeanneaux, D. Mekarnia, Eric Aristidi, E. Bondoux, Z. Challita, Jon Lawrence, Thirty Metre Telescope, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 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)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), 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, 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), 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), Australian Astronomical Observatory, Université Nice Sophia Antipolis (... - 2019) (UNS), 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), 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), Spinoglio, Luigi, and Epchtein, Nicolas

Subjects
Physics, business.industry, Turbulence, General Engineering, Ground layer, Astronomy and Astrophysics, Geodesy, 01 natural sciences, Wind speed, 010309 optics, Dome (geology), Optics, Space and Planetary Science, Anemometer, 0103 physical sciences, Surface layer, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Tower, Refractive index
Abstract

International audience; The optical turbulence above Dome C in winter is mainly concentrated in the first tens of meters above the ground. The properties of this so-called surface layer were investigated during the last two winterover by a set of sonics anemometers placed on a 45 m high tower. These anemometers provide measurements of the temperature and the wind speed vector. The sampling rate of 10 Hz allows to derivate the refractive index structure constant C_n^2. We report here the first analysis of these data.

Published
2009

32. Adaptive optics (AO) and ground-layer AO for Dome C: numerical simulation results

Author

Marcel Carbillet, C. Giordano, Anne-Lise Maire, B. Le Roux, J. Gautier, H. Trinquet, O. Pasqueron de Fommervault, Eric Aristidi, Joseph Louis LAGRANGE (LAGRANGE), 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), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, 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), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis - Faculté des Sciences (UNS UFR Sciences), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Laboratoire Hippolyte Fizeau (FIZEAU), 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), and 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)

Subjects
Physics, Field (physics), Computer simulation, business.industry, Turbulence, General Engineering, Ground layer, Strehl ratio, Astronomy and Astrophysics, 01 natural sciences, law.invention, 010309 optics, Telescope, Dome (geology), Optics, Space and Planetary Science, law, 0103 physical sciences, Adaptive optics, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics
Abstract

International audience; We present the latest results of our on-going closed-loop “end-to-end” numerical adaptive optics (AO) simulations concerning both a standard-AO and a three-star ground-layer AO system for a near-infrared 2-m class telescope at Dome C, Antarctica. We demonstrate that Dome C is an ideal site for wide-field AO-aided astronomy, define in details the AO system(s) optimized for the median turbulence profile considered, and finally show that a 0.3 Strehl ratio and 200-mas-wide stable point-spread function is reached in band J on at least a 15^prime-diameter field.

Published
2009

33. Optical turbulence and outer scales above Dome C in Antarctica

Author

Eric Aristidi, E. Fossat, H. Trinquet, J. Vernin, M. Azouit, Abdelkrim Agabi, Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux (ARTEMIS), 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), Joseph Louis LAGRANGE (LAGRANGE), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), and Laboratoire Hippolyte Fizeau (FIZEAU)

Subjects
Fried parameter, Scale (ratio), Turbulence, business.industry, 020209 energy, Astrophysics::Instrumentation and Methods for Astrophysics, 02 engineering and technology, interferometry, Geodesy, 01 natural sciences, Wind speed, site testing, 010309 optics, outer scale, Interferometry, Dome (geology), Optics, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Surface layer, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], business, Geology, Intensity (heat transfer), atmospheric effects
Abstract

International audience; Dome C in Antarctica is a particular astronomical site when considering the optical turbulence conditions. From the first winterover campaign performed in 2005 at Dome C, the set of 34 meteorological balloon profiles has been analyzed. The meteorological balloons were equipped with microthermal sensors used to sense the vertical profile of the optical turbulence intensity C2n. The C2n median profile, mean temperature and mean horizontal wind speed are given. The C2n median profile is characterized by a very strong and thin turbulent surface layer. The surface layer height is defined. The median outer scale profile at Dome C is computed using the Tatarski definition. The von Karman outer scale is also deduced. The integrated parameters as Fried parameter r0, coherence time τ0, isoplanatic angle θ0 and the spatial-coherence outer scale L0 used to define astronomical site quality, are computed at 8 m above the ground and above the turbulent surface layer.

Published
2008

34. IRAN: laboratory test bench for hypertelescope pupil-plane recombination

Author

Eric Aristidi, F. Allouche, Andreas Glindemann, Richard Douet, Farrokh Vakili, E. Fossat, Lyu Abe, Joseph Louis LAGRANGE (LAGRANGE), 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), Laboratoire Hippolyte Fizeau (FIZEAU), European Southern Observatory (ESO), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), and 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)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Set (abstract data type), Laboratory test, Interferometry, Optics, business.industry, Plane (geometry), Computer science, Laboratory experiment, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], business, Pupil, Convolution
Abstract

International audience; In 2004, our group proposed IRAN, an alternative beam-combination technique to the so-called hypertelescope imaging method introduced by Labeyrie in the 1990s. We have recently set up a laboratory experiment aiming at validating our image densification approach instead of the pupil densification scheme of Labeyrie. In our experiment, seven sub-apertures illuminated by laser sources are recombined using the IRAN scheme. The validation of the IRAN recombination consists basically in retrieving the point-spread intensity distribution (PSID), demonstrating the conservation of the object-image convolution relation. We will introduce IRAN, compare it to the hyper-telescope, and present the experimental results that we obtained.

Published
2008

35. The Software Package SPHERE: a CAOS-based numerical tool for end-to-end simulations of SPHERE/VLT

Author

P. Bendjoya, Anthony Boccaletti, David Mouillet, Marcel Carbillet, Andrea Ferrari, Kjetil Dohlen, I. Smith, Thierry Fusco, Christian Thalmann, Arthur Vigan, Laboratoire Hippolyte Fizeau (FIZEAU), 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), 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), Institute of Astronomy [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-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), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, 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), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), 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), Observatoire des Sciences de l'Univers de Grenoble (OSUG), and 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)

Subjects
Physics, business.industry, Polarimetry, Polarimeter, 01 natural sciences, Exoplanet, law.invention, 010309 optics, Integral field spectrograph, Optics, Software, Apodization, law, Computer graphics (images), 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], business, Adaptive optics, 010303 astronomy & astrophysics, Coronagraph
Abstract

International audience; SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch) is the second-generation VLT instrument devoted primarily to direct imaging and characterization of exoplanets, and allowing a large number of promising observation modes. In this framework, an IDL-based end-to-end numerical tool has been developed within the problem-solving environment CAOS (or CAOS "system"): the Software Package SPHERE, dedicated to the complete and detailed simulation of the whole instrument. It hence includes detailed instrumental modeling of the extreme adaptive optics system SAXO, the dual-band imaging camera IRDIS, the Integral Field Spectrograph (IFS), and the Zürich IMaging POLarimeter (ZIMPOL). The status of the whole package (which has now reached version 3.0) is exposed. An example of application is also detailed: a sub-system study aspect concerning the near-infrared apodized Lyot coronagraph.

Published
2008

36. MATISSE, perspective of imaging in the mid-infrared at the VLTI

Author

Lopez, B., Antonelli, P., Wolf, S., Lagarde, S., Jaffe, W., Navarro, R., Graser, U., Petrov, R., Weigelt, G., Bresson, Y., Hofmann, K. H., Beckman, U., Henning, T., Laun, W., Ch. Leinert, Robbe-Dubois, S., Vakili, F., Richichi, A., Abraham, P., C Augereau, J., Behrend, J., Ph. Berio, Berruyer, N., Chesneau, O., Clausse, J. M., Connot, C., Demyk, K., Danchi, W. C., Dugué, M., Finger, G., Flament, S., Glazenborg, A., Hannenburg, H., Heininger, M., Hugues, Y., Hron, J., Jankov, S., Kerschbaum, F., Kroes, G., Linz, H., L Lizon, J., Ph. Mathias, Mathar, R., Matter, A., Menut, J. L., Meisenheimer, K., Millour, F., Nardetto, N., Neumann, U., Nussbaum, E., Niedzielski, A., Mosoni, L., Olofsson, J., Rabbia, Y., Ratzka, T., Rigal, F., Roussel, A., Schertl, D., François-Xavier Schmider, Stecklum, B., Éric Thiébaut, Vannier, M., Valat, B., Wagner, K., Waters, L. B. F. M., Laboratoire Hippolyte Fizeau (FIZEAU), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), Observatoire de la Côte d'Azur (OCA), Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut für Astrophysik [Wien], Universität Wien, Thüringer Landessternwarte Tautenburg (TLS), 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), 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)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

International audience; MATISSE is foreseen as a mid-infrared spectro-interferometer combining the beams of up to four UTs/ATs of the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory. The related science case study demonstrates the enormous capability of a new generation mid-infrared beam combiner. MATISSE will constitute an evolution of the two-beam interferometric instrument MIDI. MIDI is a very successful instrument which offers a perfect combination of spectral and angular resolution. New characteristics present in MATISSE will give access to the mapping and the distribution of the material (typically dust) in the circumstellar environments by using a wide mid-infrared band coverage extended to L, M and N spectral bands. The four beam combination of MATISSE provides an efficient UV-coverage : 6 visibility points are measured in one set and 4 closure phase relations which can provide aperture synthesis images in the mid-infrared spectral regime.

Published
2008

37. Speckle observations with PISCO in Merate: IV. Astrometric measurements of visual binaries in 2005

Author

Luigi Pansecchi, Eric Aristidi, L. Koechlin, Stefano Basso, Robert Argyle, Jean-Louis Prieur, Marco Scardia, M. Sala, Mauro Ghigo, INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (... - 2019) (UNS), and 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)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Mean squared error, Astrophysics, 01 natural sciences, law.invention, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Telescope, Speckle pattern, Observatory, law, Position (vector), 0103 physical sciences, ADS 14783), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, binaries: close, stars: individual (ADS 684, Astronomy, Astronomy and Astrophysics, Astrometry, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], binaries: visual, MCA 55Aac, astrometry -binaries: close -binaries: visual -stars: individual (ADS 684, Stars, techniques: interferometric, Space and Planetary Science, astrometry, ADS 14783) - techniques: interferometric, Data reduction
Abstract

We present relative astrometric measurements of visual binaries made during the second semester of 2005, with the speckle camera PISCO at the 102 cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our sample contains orbital couples as well as binaries whose motion is still uncertain. The purpose of this long term program is to improve the accuracy of the orbits and determine the masses of the components. We performed 130 new observations of 120 objects, with most of the angular separations in the range 0″.1–4″, and with an average accuracy of 0″.01. Most of the position angles could be determined without the usual 180. ambiguity with the application of triple-correlation techniques, and their mean error is 0°8. We have found a possible new triple system: ADS 11077. The measurements of the closest binaries were made with a new data reduction procedure, based on model fitting of the background of the auto-correlations. As this procedure proved to be very efficient, we have re-processed the old observations of close binaries made with PISCO in Merate since 2004. We thus improved 20 measurements already published and obtained 7 new measurements for observations that were previously reported as “unresolved”. We finally present revised orbits for ADS 684, MCA 55Aac (in the Beta 1 Cyg–Albireo multiple system) and ADS 14783 for which the previously published orbits led to large residuals with our measurements and for which the new observations made since their computation allowed a significant improvement of those old orbits. The sum of the masses that we derived for those systems are consistent with the spectral type of the stars and the dynamic parallaxes are in good agreement with the parallaxes measured by Hipparcos. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Published
2008

38. Gattini: a multisite campaign for the measurement of sky brightness in Antarctica

Author

Nicholas F. H Tothill, Long-Long Feng, Xiangqun Cui, Will Saunders, Xiangyan Yuan, Zhaohui Shang, Jon Lawrence, Melinda Taylor, W. Qin, Eric Aristidi, Jingyao Hu, Xu Zhou, Timothy R. Bedding, Brice Le Roux, Maurizio Candidi, Anna M. Moore, Suzanne L. Kenyon, Elisa Distefano, Zhenxi Zhu, John W. V. Storey, Gerard van Belle, Kaspar von Braun, Patrick J. Espy, L. Sabbatini, Dennis Stello, David R. Ciardi, Lifan Wang, A. Phillips, Tim Leslie, Michael C. B. Ashley, Piero Salinari, Craig Kulesa, Huigen Yang, Tony Travouillon, Graham Allen, Yuangshen Li, Bo Sun, Chas Beichman, Reed Riddle, Maurizio Busso, J. R. Everett, Runa Briguglio, Daniel M. Luong-Van, Gino Tosti, Zhaoji Jiang, Giuseppe Cutispoto, Nicolas Suntzeff, Roberto Ragazzoni, J. Yan, University of New South Wales [Sydney] (UNSW), Joseph Louis LAGRANGE (LAGRANGE), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Dipartimento di Fisica e Geologia [Perugia], Università degli Studi di Perugia (UNIPG), Infrared Processing and Analysis Center (IPAC), California Institute of Technology (CALTECH), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Stellar Astrophysics Centre [Aarhus] (SAC), Aarhus University [Aarhus], TMT project, Department of Physics and Astronomy [College Station], Texas A&M University [College Station], Massachusetts General Hospital [Boston], Computational Biology Department [Pittsburgh], Carnegie Mellon University [Pittsburgh] (CMU), National University of Defense Technology [China], Stepp, Larry M., and Gilmozzi, Roberto

Subjects
010504 meteorology & atmospheric sciences, Meteorology, media_common.quotation_subject, Cloud cover, Site testing, 01 natural sciences, Dome (geology), Sky, Sky brightness, 0103 physical sciences, Environmental science, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Transit (satellite), 0105 earth and related environmental sciences, media_common, Antarctic plateau, Remote sensing
Abstract

We present the Gattini project: a multisite campaign to measure the optical sky properties above the two high altitude Antarctic astronomical sites of Dome C and Dome A. The Gattini-DomeC project, part of the IRAIT site testing campaign and ongoing since January 2006, consists of two ca meras for the measurement of optical sky brightness, large area cloud cover and auroral detection above the DomeC site, home of the French-Italian Conc ordia station. The cameras are transit in nature and are virtually identical except for the nature of the lenses. The cameras have operated successfully throughout the past two Antarctic winter seasons and here we present the first results obtained from the returned 2006 dataset. The Gattini-DomeA project will place a similar site testing facility at the highest point on the Antarctic plateau, Dome A, with observations commencing in 2008. The project forms a small part of a much larger venture coordinated by the Polar Research Institute of China as part of the International Polar Year whereby an automated site testing facility called PLATO will be traversed into the DomeA site. The status of this exciting and ambitious project with regards to the Gattini-DomeA cameras will be presented. Keywords: Antarctica, optical sky brightness, site testing cameras, Gattini

Published
2008

39. Sampling the ground layer of the atmosphere at Dome C using fast sonic-anemometers

Author

John W. V. Storey, D. Mekarnia, Eric Fossat, Jon Lawrence, A. W. Skidmore, Tony Travouillon, Eric Aristidi, Anna M. Moore, Thirty Metre Telescope, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Australian Astronomical Observatory, Joseph Louis LAGRANGE (LAGRANGE), 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), University of New South Wales [Sydney] (UNSW), Stepp, Larry M., and Gilmozzi, Roberto

Subjects
Physics, 010504 meteorology & atmospheric sciences, Meteorology, Turbulence, Ground layer, Sampling (statistics), Atmospheric sciences, 01 natural sciences, Wind speed, law.invention, Atmosphere, Telescope, Dome (geology), 13. Climate action, Anemometer, law, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

International audience; The ground layer turbulence at Dome C is the cause for more than 90% of the total turbulence column. While the height of this layer has been currently measured to be approximately 30m, no long term statistics is available from this part of the atmosphere. In order to plan the construction of future telescope at this site temperature site, temperature, wind speed and turbulence measurements are also necessary. Using fast sonicanemometers we present, a preliminary set of data covering January to October 2007 sampling these quantities at heights of 8, 16 and 28 meters.

Published
2008

40. Effets de la Turbulence Atmosphérique lors de l'Observation du Soleil à Haute Résolution Angulaire

Author

Berdja, Amokrane, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis, and Julien Borgnino(borgnino@unice.fr)

Subjects
optical turbulence, optique adaptative, stellar interferometry, bouillonnement de la turbulence optique, optical turbulence boiling, turbulence optique, [SDU.OTHER]Sciences of the Universe [physics]/Other, solar astrometry, interférométrie stellaire, astrométrie solaire, adaptive optics
Abstract

The observation of the Sun at high angular resolution is of great importance in astronomy. In this context, I show the effects of optical turbulence on solar images, especially on the astrometric long exposure measurements of the solar diameter. I propose a modelling, in the small perturbation approximation, of the chromatic and polychromatic local angle of arrival fluctuations, which has direct relevance for optical turbulence daytime observations. In order to extract angle of arrival fluctuations from short exposure images of solar edge, I propose an effective and stable method that consists of a photometric integration with local anisoplanatism test. This method increases the efficiency of previous approaches. It also impacts on the long exposure measurement of the solar diameter as well as on the definition of solar photometric diameter. Another way to measure daytime angle of arrival fluctuations is to do so in the pupil plane. I studied this approach with its validity and limitations. As a direct application, we propose a concept of a profiling monitor for the low altitude optical turbulence. Another important part of my work has been the modelling of the temporal variation of optical turbulence by introducing proper boiling. The theoretical framework that I propose is presented with examples (interferometry, adaptive optics...) related to various high angular resolution observation techniques in the presence of optical turbulence.; L'observation du Soleil à haute résolution angulaire est d'une grande importance en astronomie. Dans ce contexte, je montre les effets de la turbulence optique sur les images solaires, notamment sur les mesures astrométrique du diamètre solaire en longue pose. Je propose, dans l'approximation des faibles perturbations, une modélisation des fluctuations d'angle d'arrivée locales chromatiques et polychromatiques qui a des retombées directes pour les observations diurnes de la turbulence optique. Afin d'extraire les fluctuations d'angle d'arrivée à partir des images courte pose du bord solaire, je propose une approche efficace et stable qui consiste en une intégration photométrique saturée avec test de l'anisoplanétisme local. Cette méthode améliore l'efficacité des méthodes précédentes. Elle a aussi des retombées sur la mesure du diamètre solaire en longue pose et la définition du diamètre photométrique. Une autre manière de mesurer les fluctuations d'angle d'arrivée de jour est de le faire dans le plan conjugué de la pupille. J'étudie cette approche avec sa validité et ses limites. Comme application directe on présente le concept d'un moniteur profileur de la turbulence optique basse altitude. Une autre partie importante de mon travail est la modélisation de la variation temporelle de la turbulence optique en introduisant le bouillonnement propre. Le modèle théorique que je propose est présenté avec des exemples liés à des techniques diverses de l'observation à haute résolution angulaire (interférométrie, optique adaptative...) en présence de turbulence optique.

Published
2007

41. Effects of Atmospheric Turbulence on the Observation of the Sun at High Angular Resolution

Author

Berdja, Amokrane, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis, and Julien Borgnino(borgnino@unice.fr)

Subjects
optical turbulence, optique adaptative, stellar interferometry, bouillonnement de la turbulence optique, optical turbulence boiling, turbulence optique, [SDU.OTHER]Sciences of the Universe [physics]/Other, solar astrometry, interférométrie stellaire, astrométrie solaire, adaptive optics
Abstract

The observation of the Sun at high angular resolution is of great importance in astronomy. In this context, I show the effects of optical turbulence on solar images, especially on the astrometric long exposure measurements of the solar diameter. I propose a modelling, in the small perturbation approximation, of the chromatic and polychromatic local angle of arrival fluctuations, which has direct relevance for optical turbulence daytime observations. In order to extract angle of arrival fluctuations from short exposure images of solar edge, I propose an effective and stable method that consists of a photometric integration with local anisoplanatism test. This method increases the efficiency of previous approaches. It also impacts on the long exposure measurement of the solar diameter as well as on the definition of solar photometric diameter. Another way to measure daytime angle of arrival fluctuations is to do so in the pupil plane. I studied this approach with its validity and limitations. As a direct application, we propose a concept of a profiling monitor for the low altitude optical turbulence. Another important part of my work has been the modelling of the temporal variation of optical turbulence by introducing proper boiling. The theoretical framework that I propose is presented with examples (interferometry, adaptive optics...) related to various high angular resolution observation techniques in the presence of optical turbulence.; L'observation du Soleil à haute résolution angulaire est d'une grande importance en astronomie. Dans ce contexte, je montre les effets de la turbulence optique sur les images solaires, notamment sur les mesures astrométrique du diamètre solaire en longue pose. Je propose, dans l'approximation des faibles perturbations, une modélisation des fluctuations d'angle d'arrivée locales chromatiques et polychromatiques qui a des retombées directes pour les observations diurnes de la turbulence optique. Afin d'extraire les fluctuations d'angle d'arrivée à partir des images courte pose du bord solaire, je propose une approche efficace et stable qui consiste en une intégration photométrique saturée avec test de l'anisoplanétisme local. Cette méthode améliore l'efficacité des méthodes précédentes. Elle a aussi des retombées sur la mesure du diamètre solaire en longue pose et la définition du diamètre photométrique. Une autre manière de mesurer les fluctuations d'angle d'arrivée de jour est de le faire dans le plan conjugué de la pupille. J'étudie cette approche avec sa validité et ses limites. Comme application directe on présente le concept d'un moniteur profileur de la turbulence optique basse altitude. Une autre partie importante de mon travail est la modélisation de la variation temporelle de la turbulence optique en introduisant le bouillonnement propre. Le modèle théorique que je propose est présenté avec des exemples liés à des techniques diverses de l'observation à haute résolution angulaire (interférométrie, optique adaptative...) en présence de turbulence optique.

Published
2007

42. The environment of the fast rotating star Achernar - High-resolution thermal infrared imaging with VISIR in BURST mode

Author

Pierre Kervella, Armando Domiciano de Souza, 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 Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Gemini (LG), 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)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Hippolyte Fizeau (FIZEAU), 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), Université Nice Sophia Antipolis (1965 - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-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)

Subjects
Be star, Equator, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, Techniques: high angular resolution, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Apparent magnitude, Methods: observational, 0103 physical sciences, Thermal, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Stars: emission-line, Astrophysics (astro-ph), Stars: individual: Achernar, Astronomy and Astrophysics, Be, Azimuth, Interferometry, Stars, Polar wind, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics
Abstract

Context: The geometry of the circumstellar envelopes (CSE) surrounding Be stars is still uncertain, although it is often assumed that they are formed by a disk around the stellar equator and a hot polar wind. Achernar (Alpha Eri) is the nearest Be star, and we recently detected a CSE using near-IR interferometry. Aims: Our initial goal was to constrain the geometry and flux contribution of the CSE of Achernar at distances of a few tens of AU from the star, in the thermal IR domain to complement our near-IR interferometric observations. Methods: We obtained diffraction-limited images of Achernar in the thermal infrared using VISIR at the VLT. In order to freeze the turbulence, we used the BURST mode of this instrument. Results: The images obtained in the PAH1 band show a point-like source located 0.280" north-west of Achernar (projected linear separation of 12.3 AU). Its emission is 1.8 % of the flux of Achernar in this band, but is not detected in the PAH2, SiC and NeII bands. We also provide new thermal IR photometry of Achernar in four bands. Conclusions: Being aligned with the expected azimuth of the equatorial plane of Achernar, the detected source could be a main sequence stellar companion. In this case, it apparent brightness would correspond to an A7V spectral type., Comment: 4 pages, 4 figures

Published
2007

43. CONTRIBUTION À L'ÉTUDE DES SITES ASTRONOMIQUES PAR MODÉLISATION ET EXPÉRIMENTATION in situ : APPLICATION AUX SITES DE LA SILLA ET DU DÔME C POUR LES TELESCOPES GÉANTS DU FUTUR

Author

Sadibekova, Tatiana, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Université Nice Sophia Antipolis, Eric Fossat et Jean Vernin(fossat@unice.fr, and vernin@unice.fr)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, paramètres de l'optique adaptative, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], [SDU]Sciences of the Universe [physics], charactérisation de site pour l'astronomie, turbulence profiles, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, site characterization, adaptive optics parameters, profils de turbulence, turbulence atmosphérique, atmospheric turbulence
Abstract

This thesis was undertaken within the framework of the E-ELT project (European Extremely Large Telescope) where the site characterization for the future large telescopes is the paramount goal. The very important factor for astronomical observations is the atmospheric turbulence. Several techniques exist to measure the various integral parameters and the vertical profiles of optical turbulence. In this context I analyzed the various atmospheric profiling techniques applied to two astronomical sites : La Silla one ESO site in Chile and also the Antarctic site of the Dome C, which has been of great interest for the astronomers during the past few years. Therefore, the feasibility must be extensively studied, and proceed through an objective analysis of pros and cons.In the first part of my thesis, I review some important properties of Antarctic plateau. Then, I consider its geographical position and natural conditions that bring important advantages for astronomical observations at different wavelengths, and especially in the IR. Later, for understanding the seasonal behavior of the atmosphere above Dome C, the climatological situation, using the year-round data from the ECMWF (European Center for Medium-range Weather Forecasts) model for 2003-2004, is then presented. The results from the model are finally compared to the results already obtained from site testing campaigns at Concordia.In the second part of my thesis, I present vertical profiles of refractive index structure constant Cn2(h) measurements made at the 1-m telescope at La Silla Observatory (ESO, Chile) using the Generalized SCIDAR. Observations took place from July 2002 up to February 2003. I performed the data processing of 600Gb scintillation images to retrieve Cn2(h) and V(h) profiles using Maximum Entropy and Tikhonov Regularization inversion methods. Seeing values derived from C2n(h) profiles are successfully compared to the simultaneous seeing measurements taken with a DIMM. Five months statistics of the turbulent situation at La Silla Observatory are analyzed for the general qualification of the potential sites for the E-ELT project.; Cette these rentre dans le cadre du projet d'European Extremely Large Telescope (E-ELT) pour la caracterisation des sites. L'un des facteurs tres important est la turbulence atmospherique. Car c'est elle qui limite la resolution angulaire a toutes les longueurs d'onde. L'installation d'un grand telescope avec tous ses systemes complexes de correction de front d'onde par optique adaptative n ecessite une etude elaboree de l'atmosphere au-dessus du site. Plusieurs techniques permettent de mesurer les differents parametres integraux et les profils verticaux de la turbulence optique. Dans ce contexte j'ai analyse les differentes techniques de profilage atmospherique appliquees a deux sites astronomiques : La Silla le site de l'ESO au Chili et egalement le site Antarctique du Dome C, qui depuis quelques annees interesse beaucoup les astronomes. L'etude de Dome C met en evidence des conditions tres particulieres (s echeresse, froid, peu de vent) qui permettent d'envisager, meme de jour, certaines observations stellaires dans des fenetres spectrales de l'infrarouge thermique qui sont inaccessibles partout ailleurs sur Terre. Pendant l'ete austral le seeing moyen est meilleur que dans les autres sites connus. Pendant l'hiver il est degrade par la presence de la couche limite qui contient parfois jusqu'a 90% de la turbulence atmospherique dans la premiere trentaine de metres. Ceci est confirme par les mesures in situ et les resultats de re-analyses. Pour la suite, il est tres important de connaitre la distribution verticale de la turbulence qu'on obtient grace aux differentes techniques de profilage atmospherique par les mesures et par la modelisation. C'est pourquoi ici, on procede a la validation comparative du modele meteorologique europeen ECMWF(European Center for Medium-range Weather Forecasts) pour Dome C qui pourra fournir les parametres d'entree pour les divers modeles de turbulence qui de leur cote permettront d'obtenir la distribution verticale de Cn2(h) et par la suite la prevision du seeing a court et long terme.Dans le cadre general de la recherche des meilleurs sites pour le futur telescope europeen E-ELT, une campagne de mesures a ete effectuee en 2002/2003 a l'observatoire de La Silla de l'ESO au Chili au moyen d'un profileur a etoile double - le SCIDAR Generalise. On a obtenu, apres 5 mois d'observation, la statistique pour le seeing, l'angle isoplanetique, le temps de coherence et les profils verticaux de Cn2(h) et V(h). Ceci a permis de decouvrir plusieurs particularites importantes de ce site astronomique. Les valeurs du seeing ont ete comparees a celles mesurees par l'instrument DIMM. Les resultats de cette campagne sont tres importants pour decrire la situation turbulente au-dessus de ce site et ils sont egalement n ecessaires pour proceder a la simulation des systemes d'optique adaptative afin de determiner les limites observationnelles des futurs grands telescopes et specialement pour l'optique adaptative.

Published
2007

44. Abundance determination of A, Am and F stars in the Pleiades and Coma Berenices clusters

Author

Gebran, M., Monier, R., Olivier Richard, Groupe de Recherche en Astronomie et Astrophysique du Languedoc (GRAAL), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), and Richard, Olivier

Subjects
stars: abundances, Pleiades, diffusion, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], open clusters and associations: individual: Coma Berenices, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Abundances of 18 chemical elements have been derived for 27 A/Am and 16 F stars members of the Pleiades and Coma Berenices open clusters. We have specifically computed, with the Montrèal code, a series of evolutionary models for two A star members of these two clusters. None of the models reproduces entirely the overall shape of the abundance patterns. The inclusion of competing processes such as rotational mixing in the radiative zones of these stars seems necessary to improve the agreement between observed and predicted abundance patterns.

Published
2007

45. Modélisation des effets optiques de la turbulence atmosphérique pour les grands télescopes et les observations à Haute Résolution Angulaire

Author

Maire, Jérôme, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis, and Pr. Julien Borgnino & Pr. Aziz Ziad

Subjects
Optical Propagation, Grands Télescopes, Interférométrie, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Optique Adaptative, Turbulence Atmosphérique, Propagation Optique, Interferometry, Haute Résolution Angulaire, Site Testing, Atmospheric Turbulence, Large Telescopes, Tests de sites, High Angular Resolution, Adaptive Optics
Abstract

Future Extremely Large Telescopes will give us the possibility to observe with High Angular Resolution. However, their conception requires a precise knowledge of optical effects due to atmospheric turbulence at large scales. This study aims to investigate the experimental validation of optical turbulence modelization for ground based observations.The characterization of wavefront large scale properties is performed with the long baseline GI2T/REGAIN stellar interferometer with the perspective of observations with the VLTI/AMBER interferometer. In the case of large baselines, wavefront deformations do not follow the same statistical laws as in cases of shorter distances of separation. This study provides confirmation that the amplitude of wavefront spatial deformations do not increase indefinitely with the baseline extension. This highlights the saturation of variables related to spatial deformations when distances considered are larger than the value of the wavefront outer scale.The GSM ('Generalized Seeing Monitor'), an unique instrument dedicated to the wavefront outer scale measurements, is used in an extended configuration to experimentally validate the different existing models of optical turbulence during observations at the Calern Observatory. A multi-layer modelization of the outer scale is proposed to describe optical effects of atmospheric turbulence corresponding to each altitude.Finally, a part of this study was devoted to the development of the 'Monitor of Outer Scale Profile' which measures the vertical distribution of the wavefront outer scale from detection of Moon's limb position fluctuations. Several campaigns of observations have been performed at the "Observatoire de Haute Provence" and Mauna Kea Observatory and first measurements of wavefront outer scale profiles are presented.; Les futurs très grands télescopes donneront la possibilité d'effectuer des observations à très Haute Résolution Angulaire, mais leur conception nécessite une connaissance précise des effets optiques de la turbulence atmosphérique sur de grandes échelles spatiales. Cette étude porte sur la validation expérimentale de la modélisation de la turbulence optique lors de l'observation astronomique à partir du sol.La caractérisation des propriétés spatiales du front d'onde est effectuée à partir des grandes bases de mesure utilisées par l'interféromètres stellaire optique GI2T / REGAIN dans la perspective d'observations avec l'interféromètre VLTI / AMBER. A ces échelles, les déformations du front d'onde ne suivent pas les mêmes lois statistiques et cette étude confirme que l'amplitude des déformations spatiales du front d'onde n'augmente pas indéfiniment avec l'allongement de la base de mesure. Cette étude met en évidence la saturation des grandeurs liées aux déformations spatiales lorsque les distances considérées dépassent la valeur de l'échelle externe de cohérence spatiale du front d'onde.Le GSM ("Generalized Seeing Monitor"), unique instrument dédié à la mesure de l'échelle externe, est utilisé dans une configuration étendue pour tester expérimentalement les différents modèles existants de turbulence optique lors d'observations sur le site de Calern. Une modélisation multi-couche de l'échelle externe est aussi proposée afin de rendre compte des effets optiques de la turbulence atmosphérique selon sa distribution an altitude. Les résultats de cette étude permettent de mieux dimensionner les systèmes d'optique adaptative de nouvelle génération associés aux futurs grands télescopes et interféromètres à très grandes bases.Enfin, cette étude a consisté à développer l'instrument MOSP ("Monitor of Outer Scale Profile") mesurant la distribution verticale de l'échelle externe à partir de l'observation du limbe de la Lune. Plusieurs campagnes d'observation ont été effectuées aux Observatoires de Haute Provence et de Mauna Kea et les premières mesures de profils d'échelle externe sont présentées.

Published
2007

46. Optical configuration and analysis of the AMBER/VLTI instrument

Author

S. Robbe-Dubois, S. Lagarde, R. G. Petrov, F. Lisi, U. Beckmann, P. Antonelli, Y. Bresson, G. Martinot-Lagarde, A. Roussel, P. Salinari, M. Vannier, A. Chelli, M. Dugué, G. Duvert, S. Gennari, L. Glück, P. Kern, E. Le Coarer, F. Malbet, F. Millour, K. Perraut, P. Puget, F. Rantakyrö, E. Tatulli, G. Weigelt, G. Zins, M. Accardo, B. Acke, K. Agabi, E. Altariba, B. Arezki, E. Aristidi, C. Baffa, J. Behrend, T. Blöcker, S. Bonhomme, S. Busoni, F. Cassaing, J.-M. Clausse, J. Colin, C. Connot, L. Delage, A. Delboulbé, A. Domiciano de Souza, T. Driebe, P. Feautrier, D. Ferruzzi, T. Forveille, E. Fossat, R. Foy, D. Fraix-Burnet, A. Gallardo, E. Giani, C. Gil, A. Glentzlin, M. Heiden, M. Heininger, O. Hernandez Utrera, K.-H. Hofmann, D. Kamm, M. Kiekebusch, S. Kraus, D. Le Contel, J.-M. Le Contel, T. Lesourd, B. Lopez, M. Lopez, Y. Magnard, A. Marconi, G. Mars, P. Mathias, P. Mège, J.-L. Monin, D. Mouillet, D. Mourard, E. Nussbaum, K. Ohnaka, J. Pacheco, C. Perrier, Y. Rabbia, S. Rebattu, F. Reynaud, A. Richichi, A. Robini, M. Sacchettini, D. Schertl, M. Schöller, W. Solscheid, A. Spang, P. Stee, P. Stefanini, M. Tallon, I. Tallon-Bosc, D. Tasso, L. Testi, F. Vakili, O. von der Lühe, J.-C. Valtier, N. Ventura, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Gemini (LG), 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)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Radioastronomie (MPIFR), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Institute of Astronomy [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Laboratoire Hippolyte Fizeau (FIZEAU), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Galilée (Galilée), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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, and 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)

Subjects
FOS: Physical sciences, Astrophysics, 01 natural sciences, Stability (probability), 010309 optics, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Optics, numerical, interferometers, instrumentation: high angular resolution, 0103 physical sciences, Visibility, 010303 astronomy & astrophysics, Physics, Basis (linear algebra), Spatial filter, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Emphasis (telecommunications), Astrophysics (astro-ph), Astronomy and Astrophysics, Differential phase, Transmission (telecommunications), Space and Planetary Science, methods : analytical, business, Realization (systems), laboratory
Abstract

This paper describes the design goals and engineering efforts that led to the realization of AMBER (Astronomical Multi BEam combineR) and to the achievement of its present performance. On the basis of the general instrumental concept, AMBER was decomposed into modules whose functions and detailed characteristics are given. Emphasis is put on the spatial filtering system, a key element of the instrument. We established a budget for transmission and contrast degradation through the different modules, and made the detailed optical design. The latter confirmed the overall performance of the instrument and defined the exact implementation of the AMBER optics. The performance was assessed with laboratory measurements and commissionings at the VLTI, in terms of spectral coverage and resolution, instrumental contrast higher than 0.80, minimum magnitude of 11 in K, absolute visibility accuracy of 1%, and differential phase stability of 1E-3 rad over one minute., Comment: 14 pages

Published
2007

47. Differential speckle interferometry: in-depth analysis of the solar photosphere

Author

M. Faurobert, Frédéric Paletou, C. Grec, G. Ricort, C. Aime, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées

Subjects
Astrophysics, 01 natural sciences, law.invention, Sun: granulation, Telescope, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Speckle pattern, Optics, law, 0103 physical sciences, Wilson effect, 010303 astronomy & astrophysics, Physics, Photosphere, Sunspot, 010308 nuclear & particles physics, business.industry, techniques: high angular resolution, Astronomy and Astrophysics, Solar telescope, Interferometry, Space and Planetary Science, Speckle imaging, line: formation, business, Sun: atmosphere
Abstract

International audience; Aims.We present the results of an experiment performed at the solar telescope THEMIS in 2002 to measure the depth over which the solar granulation extends in the photosphere. Methods: Observations made in the 523.3 nm and 557.6 nm photospheric non-magnetic iron lines were correlated with images in the continuum using spectrograms. The difference in depth between the different levels in the photosphere is projected into a difference of position along the slit of the spectrograph, using a perspective effect similar to the well-known Wilson effect for sunspots. This requires measuring displacements, ones much smaller than the telescope resolution. This is made possible by using a differential speckle interferometric technique, cross-correlating images taken in the continuum and the line. The method is not adapted to following displacements of structures in the core of strong lines, due to their difference in shapes with the structures observed in the continuum. In this case, a sequential cross-spectrum method is developed to cross-correlate images taken at close wavelengths. Results: The raw results are surprising: displacements measured in the blue and the red wings of a line have opposite signs! North and South observations, however, clearly show the expected behavior attributed to a perspective effect. After a description of the observations, we give a first interpretation of the results. The main part of the observed displacement comes from the effect of unresolved Doppler shifts produced by horizontal velocities in the solar photosphere. The perspective effect we seek appears as a second-order term; we find that its amplitude is 2 or 3 times larger than predicted by theoretical 1D models. In the core of strong lines we detect a contrast inversion that also shows up in the cross-correlation function as an anti-correlation peak at line center. Conclusions: .This first use of the differential speckle interferometry technique on the Sun is quite promising for 3D studies at high spatial resolution. Further observations with very good image quality are needed to take advantage of this new technique. THEMIS is operated on the Island of Tenerife by CNRS-CNR in the Spanish Observatorio del Teide of the Instituto de Astrofísica de Canarias.

Published
2007

48. Near-infrared interferometry of eta Carinae with spectral resolutions of 1 500 and 12 000 using AMBER/VLTI

Author

G. Weigelt, S. Kraus, T. Driebe, R. G. Petrov, K.-H. Hofmann, F. Millour, O. Chesneau, D. Schertl, F. Malbet, D. J. Hillier, T. Gull, K. Davidson, A. Domiciano de Souza, P. Antonelli, U. Beckmann, Y. Bresson, A. Chelli, M. Dugué, G. Duvert, S. Gennari, L. Glück, P. Kern, S. Lagarde, E. Le Coarer, F. Lisi, K. Perraut, P. Puget, F. Rantakyrö, S. Robbe-Dubois, A. Roussel, E. Tatulli, G. Zins, M. Accardo, B. Acke, K. Agabi, E. Altariba, B. Arezki, E. Aristidi, C. Baffa, J. Behrend, T. Blöcker, S. Bonhomme, S. Busoni, F. Cassaing, J.-M. Clausse, J. Colin, C. Connot, A. Delboulbé, P. Feautrier, D. Ferruzzi, T. Forveille, E. Fossat, R. Foy, D. Fraix-Burnet, A. Gallardo, E. Giani, C. Gil, A. Glentzlin, M. Heiden, M. Heininger, O. Hernandez Utrera, D. Kamm, M. Kiekebusch, D. Le Contel, J.-M. Le Contel, T. Lesourd, B. Lopez, M. Lopez, Y. Magnard, A. Marconi, G. Mars, G. Martinot-Lagarde, P. Mathias, P. Mège, J.-L. Monin, D. Mouillet, D. Mourard, E. Nussbaum, K. Ohnaka, J. Pacheco, C. Perrier, Y. Rabbia, S. Rebattu, F. Reynaud, A. Richichi, A. Robini, M. Sacchettini, M. Schöller, W. Solscheid, A. Spang, P. Stee, P. Stefanini, M. Tallon, I. Tallon-Bosc, D. Tasso, L. Testi, F. Vakili, O. von der Lühe, J.-C. Valtier, M. Vannier, N. Ventura, K. Weis, M. Wittkowski, Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Gemini (LG), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Département Fresnel (FRESNEL), Observatoire de la Côte d'Azur, Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), European Southern Observatory (ESO), ONERA - The French Aerospace Lab [Châtillon], ONERA, Observatoire de la Côte d'Azur (OCA), Centre National de la Recherche Scientifique (CNRS), Canada-France-Hawaii Telescope Corporation (CFHT), National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i [Honolulu] (UH), Centre de Recherche Astrophysique de Lyon (CRAL), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Association EURATOM-CEA (CEA/DSM/DRFC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux (ARTEMIS), PHOTONIQUE, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), 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), ONERA-Université Paris Saclay (COmUE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-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), 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), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics::High Energy Astrophysical Phenomena, Continuum (design consultancy), Astrophysics, 01 natural sciences, 7. Clean energy, circumstellar matter, emission-line Be, outflows, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Atmospheric radiative transfer codes, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, Spectral resolution, 010303 astronomy & astrophysics, infrared: stars, Astrophysics::Galaxy Astrophysics, Physics, Very Large Telescope, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Near-infrared spectroscopy, Gamma ray, Astronomy and Astrophysics, Position angle, stars: individual: ηCarinae, winds, 13. Climate action, Space and Planetary Science, techniques: interferometric, stars: mass-loss
Abstract

Aims. We present the first NIR spectro-interferometry of the LBV ? Carinae. The observations were performed with the AMBER instrument of the ESO Very Large Telescope Interferometer (VLTI) using baselines from 42 to 89 m. The aim of this work is to study the wavelength dependence of ? Car's optically thick wind region with a high spatial resolution of 5 mas (11 AU) and high spectral resolution. Methods: The observations were carried out with three 8.2 m Unit Telescopes in the K-band. The raw data are spectrally dispersed interferograms obtained with spectral resolutions of 1500 (MR-K mode) and 12 000 (HR-K mode). The MR-K observations were performed in the wavelength range around both the He I 2.059 ?m and the Br? 2.166 ?m emission lines, the HR-K observations only in the Br? line region. Results: The spectrally dispersed AMBER interferograms allow the investigation of the wavelength dependence of the visibility, differential phase, and closure phase of ? Car. In the K-band continuum, a diameter of 4.0±0.2 mas (Gaussian FWHM, fit range 28-89 m baseline length) was measured for ? Car's optically thick wind region. If we fit Hillier et al. (2001, ApJ, 553, 837) model visibilities to the observed AMBER visibilities, we obtain 50% encircled-energy diameters of 4.2, 6.5 and 9.6 mas in the 2.17 ?m continuum, the He I, and the Br? emission lines, respectively. In the continuum near the Br? line, an elongation along a position angle of 120°±15° was found, consistent with previous VINCI/VLTI measurements by van Boekel et al. (2003, A&A, 410, L37). We compare the measured visibilities with predictions of the radiative transfer model of Hillier et al. (2001), finding good agreement. Furthermore, we discuss the detectability of the hypothetical hot binary companion. For the interpretation of the non-zero differential and closure phases measured within the Br? line, we present a simple geometric model of an inclined, latitude-dependent wind zone. Our observations support theoretical models of anisotropic winds from fast-rotating, luminous hot stars with enhanced high-velocity mass loss near the polar regions. Based on observations collected at the European Southern Observatory, Paranal, Chile, within the AMBER guaranteed time programme 074.A-9025 and the VLTI science demonstration programme 074.A-9024.

Published
2007

49. Direct constraint on the distance of Gamma2 Velorum from AMBER/VLTI observations

Author

F. Millour, R. G. Petrov, O. Chesneau, D. Bonneau, L. Dessart, C. Bechet, I. Tallon-Bosc, M. Tallon, E. Thiébaut, F. Vakili, F. Malbet, D. Mourard, P. Antonelli, U. Beckmann, Y. Bresson, A. Chelli, M. Dugué, G. Duvert, S. Gennari, L. Glück, P. Kern, S. Lagarde, E. Le Coarer, F. Lisi, K. Perraut, P. Puget, F. Rantakyrö, S. Robbe-Dubois, A. Roussel, E. Tatulli, G. Weigelt, G. Zins, M. Accardo, B. Acke, K. Agabi, E. Altariba, B. Arezki, E. Aristidi, C. Baffa, J. Behrend, T. Blöcker, S. Bonhomme, S. Busoni, F. Cassaing, J.-M. Clausse, J. Colin, C. Connot, A. Delboulbé, A. Domiciano de Souza, T. Driebe, P. Feautrier, D. Ferruzzi, T. Forveille, E. Fossat, R. Foy, D. Fraix-Burnet, A. Gallardo, E. Giani, C. Gil, A. Glentzlin, M. Heiden, M. Heininger, O. Hernandez Utrera, K.-H. Hofmann, D. Kamm, M. Kiekebusch, S. Kraus, D. Le Contel, J.-M. Le Contel, T. Lesourd, B. Lopez, M. Lopez, Y. Magnard, A. Marconi, G. Mars, G. Martinot-Lagarde, P. Mathias, P. Mège, J.-L. Monin, D. Mouillet, E. Nussbaum, K. Ohnaka, J. Pacheco, C. Perrier, Y. Rabbia, S. Rebattu, F. Reynaud, A. Richichi, A. Robini, M. Sacchettini, D. Schertl, M. Schöller, W. Solscheid, A. Spang, P. Stee, P. Stefanini, D. Tasso, L. Testi, O. von der Lühe, J.-C. Valtier, M. Vannier, N. Ventura, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 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)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), 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, 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), Laboratoire Gemini (LG), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-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), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Radioastronomie (MPIFR), European Southern Observatory (ESO), PHOTONIQUE, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Observatoire de la Côte d'Azur (OCA), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), AMBER, Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, 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), Centre National de la Recherche Scientifique (CNRS), ONERA, 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), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3)

Subjects
Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Observable, Ranging, Astrophysics, Spectral bands, Position angle, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, 0103 physical sciences, Binary system, 010303 astronomy & astrophysics
Abstract

International audience; In this work, we present the first AMBER observations, of the Wolf-Rayet and O (WR+O) star binary system y² Velorum. The AMBER instrument was used with the telescopes UT2, UT3, and UT4 on baselines ranging from 46m to 85m. It delivered spectrally dispersed visibilities, as well as differential and closure phases, with a resolution R = 1500 in the spectral band 1.95-2.17 micron. We interpret these data in the context of a binary system with unresolved components, neglecting in a first approximation the wind-wind collision zone flux contribution. We show that the AMBER observables result primarily from the contribution of the individual components of the WR+O binary system. We discuss several interpretations of the residuals, and speculate on the detection of an additional continuum component, originating from the free-free emission associated with the wind-wind collision zone (WWCZ), and contributing at most to the observed K-band flux at the 5% level. The expected absolute separation and position angle at the time of observations were 5.1±0.9mas and 66±15° respectively. However, we infer a separation of 3.62+0.11-0.30 mas and a position angle of 73+9-11°. Our analysis thus implies that the binary system lies at a distance of 368+38-13 pc, in agreement with recent spectrophotometric estimates, but significantly larger than the Hipparcos value of 258+41-31 pc.

Published
2007

50. AMBER, the near-infrared spectro-interferometric three-telescope VLTI instrument

Author

Franco Lisi, Denis Mourard, K. Agabi, A. Glentzlin, P. Stefanini, Piero Salinari, G. Martinot-Lagarde, J. M. Clausse, Markus Schöller, Philippe Mathias, O. Hernandez Utrera, E. Nussbaum, J.-C. Valtier, A. Spang, Carlo Baffa, Fabien Malbet, Udo Beckmann, Michel Tallon, Alain Chelli, Sandro Gennari, O. von der Lühe, Pierre Mege, M. Accardo, Karl-Heinz Hofmann, C. Perrier, Mario Kiekebusch, Keiichi Ohnaka, M. Heiden, Ph. Stee, S. Robbe-Dubois, C. Connot, Frédéric Cassaing, T. Lesourd, D. Ferruzzi, Dieter Schertl, M. Sacchettini, L. Gluck, P. Kern, Gerd Weigelt, Alessandro Marconi, D. Mouillet, F. Vakili, S. Busoni, Renaud Foy, J. M. Le Contel, Florentin Millour, A. Robini, J. Behrend, D. Tasso, Leonardo Testi, D. Kamm, Isabelle Tallon-Bosc, Didier Fraix-Burnet, Y. Bresson, P. Antonelli, François Reynaud, T. Forveille, Yves Magnard, Bruno Lopez, C. Gil, Andrea Richichi, E. Le Coarer, E. Tatulli, J. Colin, Martin Vannier, S. Lagarde, G. Mars, Gilles Duvert, A. Domiciano de Souza, A. Gallardo, T. Blöcker, José Pacheco, Thomas Driebe, E. Altariba, A. Roussel, Stefan Kraus, Romain Petrov, Eric Aristidi, Elisabetta Giani, Morgan Lopez, K. Perraut, Philippe Feautrier, M. Heininger, D. Le Contel, N. Ventura, Yves Rabbia, S. Rebattu, J. L. Monin, Gérard Zins, Bram Acke, Fredrik T. Rantakyrö, A. Delboulbe, M. Dugué, W. Solscheid, Pascal Puget, Brahim Arezki, S. Bonhomme, E. Fossat, Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire Gemini (LG), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Département Fresnel (FRESNEL), Observatoire de la Côte d'Azur, Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), European Southern Observatory (ESO), Laboratoire Universitaire d'Astrophysique de Nice, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), ONERA - The French Aerospace Lab [Châtillon], ONERA, Observatoire de la Côte d'Azur (OCA), Centre National de la Recherche Scientifique (CNRS), Canada-France-Hawaii Telescope Corporation (CFHT), National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i [Honolulu] (UH), Centre de Recherche Astrophysique de Lyon (CRAL), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Association EURATOM-CEA (CEA/DSM/DRFC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, PHOTONIQUE, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 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)-Centre National de la Recherche Scientifique (CNRS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-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), 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, 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), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), ONERA-Université Paris Saclay (COmUE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), 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), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3)

Subjects
[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], techniques, Context (language use), Astrophysics, 01 natural sciences, law.invention, 010309 optics, Telescope, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Optics, Palomar Testbed Interferometer, law, Observatory, instrumentation: high angular resolution, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Scientific instrument, Physics, Very Large Telescope, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Interferometry, Space and Planetary Science, interferometric, Closure phase, business, techniques: spectroscopic
Abstract

Context: Optical long-baseline interferometry is moving a crucial step forward with the advent of general-user scientific instruments that equip large aperture and hectometric baseline facilities, such as the Very Large Telescope Interferometer (VLTI). Aims: AMBER is one of the VLTI instruments that combines up to three beams with low, moderate and high spectral resolutions in order to provide milli-arcsecond spatial resolution for compact astrophysical sources in the near-infrared wavelength domain. Its main specifications are based on three key programs on young stellar objects, active galactic nuclei central regions, masses, and spectra of hot extra-solar planets. Methods: These key science goals led to scientific specifications, which were used to propose and then validate the instrument concept. AMBER uses single-mode fibers to filter the entrance signal and to reach highly accurate, multiaxial three-beam combination, yielding three baselines and a closure phase, three spectral dispersive elements, and specific self-calibration procedures. Results: The AMBER measurements yield spectrally dispersed calibrated visibilities, color-differential complex visibilities, and a closure phase allows astronomers to contemplate rudimentary imaging and highly accurate visibility and phase differential measurements. AMBER was installed in 2004 at the Paranal Observatory. We describe here the present implementation of the instrument in the configuration with which the astronomical community can access it. Conclusions: .After two years of commissioning tests and preliminary observations, AMBER has produced its first refereed publications, allowing assessment of its scientific potential.

Published
2007

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