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51. SAXO: the extreme adaptive optics system of SPHERE (I) system overview and global laboratory performance

Author: Denis Perret, Kjetil Dohlen, Cyril Petit, Mark Downing, Hans Martin Schmid, Philippe Feautrier, Jean-François Sauvage, Dimitri Mawet, Anne Costille, David Mouillet, Julien Girard, Marcos Suarez, Arnaud Sevin, Bernardo Salasnich, Francois Wildi, Arthur Vigan, Ronald Roelfsema, Pierre Baudoz, Markus Kasper, Pascal Puget, Sylvain Rochat, Christian Soenke, Enrico Fedrigo, Thierry Fusco, Jared O'Neal, Andrea Baruffolo, Jean-Luc Beuzit, Emmanuel Hugot, ONERA - The French Aerospace Lab [Châtillon], ONERA, 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)-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), European Southern Observatory (ESO), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Institut de Planétologique et d'Astrophysique de Institut de Planétologique et d'Astrophysique de Grenoble, Institute of Astronomy [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), 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), NOVA-ASTRON, ONERA-Université Paris Saclay (COmUE), 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), 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]), 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), Université de Genève = University of Geneva (UNIGE), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), ITA, FRA, DEU, NLD, and CHE
Subjects: IMAGERIE À HAUT CONTRASTE, OPTIQUE ADAPTATIVE, 7. Clean energy, 01 natural sciences, law.invention, 010309 optics, Telescope, law, Observatory, 0103 physical sciences, Adaptive optics, 010303 astronomy & astrophysics, Instrumentation, Coronagraph, Remote sensing, EXOPLANETE, Physics, Very Large Telescope, Mechanical Engineering, Strehl ratio, Astronomy and Astrophysics, H band, Exoplanet, Electronic, Optical and Magnetic Materials, Space and Planetary Science, Control and Systems Engineering, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic
Abstract: International audience; The direct imaging of exoplanet is a leading field of today’s astronomy. The photons coming from the planet carry precious information on the chemical composition of its atmosphere. The second-generation instrument, Spectro-Polarimetric High contrast Exoplanet Research (SPHERE), dedicated to detection, photometry and spectral characterization of Jovian-like planets, is now in operation on the European very large telescope. This instrument relies on an extreme adaptive optics (XAO) system to compensate for atmospheric turbulence as well as for internal errors with an unprecedented accuracy. We demonstrate the high level of performance reached by the SPHERE XAO system (SAXO) during the assembly integration and test (AIT) period. In order to fully characterize the instrument quality, two AIT periods have been mandatory. In the first phase at Observatoire de Paris, the performance of SAXO itself was assessed. In the second phase at IPAG Grenoble Observatory, the operation of SAXO in interaction with the overall instrument has been optimized. In addition to the first two phases, a final check has been performed after the reintegration of the instrument at Paranal Observatory, in the New Integration Hall before integration at the telescope focus. The final performance aimed by the SPHERE instrument with the help of SAXO is among the highest Strehl ratio pretended for an operational instrument (90% in H band, 43% in V band in a realistic turbulence r0, and wind speed condition), a limit R magnitude for loop closure at 15, and a robustness to high wind speeds. The full-width at half-maximum reached by the instrument is 40 mas for infrared in H band and unprecedented 18.5 mas in V band.; L'imagerie directe d'exoplanètes est un domaine phare de l'astronomie actuelle. Les photons issus de la planète sont porteurs d'une information précieuse sur la composition chimique de son atmosphère. L'instrument de seconde génération SPHERE, Spectro-Polarimetri High-contrast Exoplanet Research, dédié à la détection la photométrie et la caractérisation spectrale de planètes joviennes, est maintenant en opération sur le très grand télescope Européen (VLT). Cet instrument repose sur une optique adaptative à très hautes performances (XAO) pour compenser les turbulences atmosphériques, comme les défauts optiques internes de l'instrument lui-même. Nous démontrons les très hauts niveaux de performance atteint par l'instrument SPHERE et son système de XAO SAXO, pendant la phase d'intégration (AIT). Pour pleinement caractériser les performances de l'instrument, deux périodes d'AIT ont été obligatoires. Dans la première phase à l'Observatoire de Paris, les performances de l'optique adaptative seule ont été obtenues. Dans la seconde phase à l'observatoire de Grenoble, l'opération de SAXO en interaction avec le reste de l'instrument ont été optimisées. En sus, une vérification finale a été faite au foyer du télescope. Les performances atteintes par SPHERE avec l'aide de SAXO sont parmi les plus hauts rapports de Strehl jamais atteint pour un instrument opérationnel (90% en bande H, 43% en bande V, sous hypothèse de turbulence et de vent classiques), et surtout une magnitude limite de R=15. La FHWM (largeur à mi-hauteur, la résolution de l'instrument) atteinte en bande H est de 40mas, et atteint une valeur sans précédent de 18.5mas en bande V.
Published: 2016
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52. First light of the VLT planet finder SPHERE. II. The physical properties and the architecture of the young systems PZ Telescopii and HD 1160 revisited

Author: Th. Henning, Emmanuel Hugot, Cyril Petit, Julien Milli, Massimo Turatto, Dimitri Mawet, Silvano Desidera, M. Kasper, O. Möller-Nilsson, Stéphane Udry, Alice Zurlo, A. Pavlov, Enrico Giro, Cecile Gry, M. Millward, Andrea Baruffolo, David Ehrenreich, Sergio Messina, Enrico Cascone, Jean-Luc Beuzit, M. Llored, T. Kopytova, Zahed Wahhaj, Andreas Bazzon, P. Martinez, Norbert Hubin, C. Moutou, Mickael Bonnefoy, Thibaut Moulin, Raffaele Gratton, Kjetil Dohlen, P. Blanchard, L. Weber, S. Rochat, Ch. Ginski, Riccardo Claudi, Pascal Puget, Anne Costille, Alain Origne, M. Carle, D. Le Mignant, Gael Chauvin, David Mouillet, H. M. Schmid, A. Delboulbe, M. Feldt, Anthony Boccaletti, Raphaël Galicher, Arthur Vigan, J. Pragt, D. Gisler, C. Thalmann, Jacopo Antichi, L. Gluck, Jose Ramos, J. de Boer, Anne-Marie Lagrange, Anne-Lise Maire, Ronald Roelfsema, Thierry Fusco, Julien Girard, Farrokh Vakili, Dino Mesa, Bernardo Salasnich, Maud Langlois, V. De Caprio, M. Jaquet, Carsten Dominik, Jean-François Sauvage, Francois Wildi, F. Madec, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), 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), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], 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), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), INAF - Osservatorio Astrofisico di Catania (OACT), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Institute for Astronomy [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Geneva Observatory, University of Geneva [Switzerland], Universidad Diego Portales [Santiago] (UDP), Departamento de Astronomia (DAS), Universidad de Santiago de Chile [Santiago] (USACH), 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), Euratom/UKAEA Fusion Assoc., Culham Science Centre [Abingdon], Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), ONERA - The French Aerospace Lab [Châtillon], ONERA, Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), ESO, Physics Department [Garching], Technical University of Munich (TUM)-Technical University of Munich (TUM), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS 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), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Canada-France-Hawaii Telescope Corporation, NASA Goddard Space Flight Center (GSFC), De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies (MONARIS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Joseph Louis LAGRANGE (LAGRANGE), 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), European Synchrotron Radiation Facility (ESRF), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), 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]), Universiteit Leiden, 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), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Université de Genève = University of Geneva (UNIGE), ONERA-Université Paris Saclay (COmUE), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Environnements et Paléoenvironnements OCéaniques (EPOC), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-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)-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), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Low Energy Astrophysics (API, FNWI)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, Very Large Telescope, 010308 nuclear & particles physics, Metallicity, Brown dwarf, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Exoplanet, Luminosity, Photometry (optics), Space and Planetary Science, 0103 physical sciences, Spectral energy distribution, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: [Abridged] Context. The young systems PZ Tel and HD 1160, hosting known low-mass companions, were observed during the commissioning of the new planet finder SPHERE with several imaging and spectroscopic modes. Aims. We aim to refine the physical properties and architecture of both systems. Methods. We use SPHERE commissioning data and REM observations, as well as literature and unpublished data from VLT/SINFONI, VLT/NaCo, Gemini/NICI, and Keck/NIRC2. Results. We derive new photometry and confirm the nearly daily photometric variability of PZ Tel A. Using literature data spanning 38 yr, we show that the star also exhibits a long-term variability trend. The 0.63-3.8 mic SED of PZ Tel B allows us to revise its properties: spectral type M7+/-1, Teff=2700+/-100 K, log(g)0.66) of PZ Tel B. For e4 MJ) outside 0.5" for the PZ Tel system. We also show that K1-K2 color can be used with YJH low-resolution spectra to identify young L-type companions, provided high photometric accuracy (, 25 pages, 23 figures, accepted for publication in A&A on Oct. 13th, 2015; version including language editing. Typo on co-author name on astroph page corrected, manuscript unchanged
Published: 2016
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53. Atmospheric characterization of Proxima b by coupling the Sphere high-contrast imager to the Espresso spectrograph

Author: Ignas Snellen, U. Conod, Sascha P. Quanz, Stéphane Udry, Francesco Pepe, Anthony Cheetham, Nuno C. Santos, Damien Ségransan, C. Lovis, Nicola Astudillo-Defru, T. Forveille, X. Delfosse, Pedro Figueira, Xavier Bonfils, H. M. Schmid, David Ehrenreich, J. L. Beuzit, David Mouillet, J. H. C. Martins, and Francois Wildi
Subjects: 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, law.invention, Telescope, Espresso, Planet, law, 0103 physical sciences, Spectral resolution, 010303 astronomy & astrophysics, Spectrograph, Instrumentation and Methods for Astrophysics (astro-ph.IM), 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Exoplanet, True mass, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. The temperate Earth-mass planet Proxima b is the closest exoplanet to Earth and represents what may be our best ever opportunity to search for life outside the Solar System. Aims. We aim at directly detecting Proxima b and characterizing its atmosphere by spatially resolving the planet and obtaining high-resolution reflected-light spectra. Methods. We propose to develop a coupling interface between the SPHERE high-contrast imager and the new ESPRESSO spectrograph, both installed at ESO VLT. The angular separation of 37 mas between Proxima b and its host star requires the use of visible wavelengths to spatially resolve the planet on a 8.2-m telescope. At an estimated planet-to-star contrast of ~10^-7 in reflected light, Proxima b is extremely challenging to detect with SPHERE alone. However, the combination of a ~10^3-10^4 contrast enhancement from SPHERE to the high spectral resolution of ESPRESSO can reveal the planetary spectral features and disentangle them from the stellar ones. Results. We find that significant but realistic upgrades to SPHERE and ESPRESSO would enable a 5-sigma detection of the planet and yield a measurement of its true mass and albedo in 20-40 nights of telescope time, assuming an Earth-like atmospheric composition. Moreover, it will be possible to probe the O2 bands at 627, 686 and 760 nm, the water vapour band at 717 nm, and the methane band at 715 nm. In particular, a 3.6-sigma detection of O2 could be made in about 60 nights of telescope time. Those would need to be spread over 3 years considering optimal observability conditions for the planet. Conclusions. The very existence of Proxima b and the SPHERE-ESPRESSO synergy represent a unique opportunity to detect biosignatures on an exoplanet in the near future. It is also a crucial pathfinder experiment for the development of Extremely Large Telescopes and their instruments (abridged)., Comment: 16 pages, 7 figures, revised version accepted to A&A
Published: 2016
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54. The CHEOPS instrument on-ground calibration system

Author: M. Sordet, A. Deline, Francois Wildi, Bruno Chazelas, and M. Sarajlic
Subjects: Physics, Time delay and integration, media_common.quotation_subject, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Exoplanet, Stars, Spitzer Space Telescope, Sky, Planet, Radiometry, Satellite, Astrophysics::Earth and Planetary Astrophysics, Remote sensing, media_common
Abstract: The CHaracterising ExOPlanet Satellite (CHEOPS) is a joint ESA-Switzerland space mission dedicated to the search for exoplanet photometric transits. Its launch readiness is expected at the end of 2017. The CHEOPS instrument will be the first space telescope dedicated to search for transits on bright stars already known to host planets. By being able to point at nearly any location on the sky, it will provide the unique capability of determining accurate radii for a subset of those planets for which the mass has already been estimated from ground-based spectroscopic surveys. To reach its goals CHEOPS will measure photometric signals with a precision of 20 ppm in 6 hours of integration time for a 9th magnitude star. This corresponds to a signal-to-noise ratio of 5 for a transit of an Earth-sized planet orbiting a solar-sized star. Achieving the precision goal requires thorough post-processing of the data acquired by the CHEOPS' instrument system (CIS) in order to remove as much as possible the instrument's signature. To this purpose, a rigorous calibration campaign will be conducted after the CIS tests in order to measure, its behavior under the different environmental conditions. The main tool of this calibration campaign is a custom-made calibration system that will inject a stimulus beam in the CIS and measure its response to the variation of electrical and environmental parameters. These variations will be compiled in a correction model. Ultimately, the CIS photometric performance will be measured on an artificial star, applying the correction model This paper addresses the requirements applicable to the calibration system, its design and its design performance.
Published: 2015
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55. High‐Resolution Mid‐Infrared Imaging of the Asymptotic Giant Branch Star RV Bootis with the Steward Observatory Adaptive Optics System

Author: Laird M. Close, D. Potter, Aigen Li, P. M. Hinz, Francois Wildi, Michael Lloyd-Hart, Beth Biller, Benjamin D. Oppenheimer, William F. Hoffmann, G. Brusa, D. Miller, and John H. Bieging
Subjects: Physics, 010308 nuclear & particles physics, Strehl ratio, Astronomy and Astrophysics, Astrophysics, Position angle, 01 natural sciences, Planetary nebula, Wavelength, Space and Planetary Science, Observatory, 0103 physical sciences, Spectral energy distribution, Asymptotic giant branch, Adaptive optics, 010303 astronomy & astrophysics
Abstract: We present high resolution (~0.1"), very high Strehl ratio (0.97+-0.03) mid-infrared (IR) adaptive optics (AO) images of the AGB star RV Boo utilizing the MMT adaptive secondary AO system. RV Boo was observed at a number of wavelengths over two epochs (9.8 um in May 2003, 8.8, 9.8 and 11.7 um in February 2004) and appeared slightly extended at all wavelengths. While the extension is very slight at 8.8 and 11.7 um data, the extension is somewhat more pronounced at 9.8 um. With such high Strehls we can achieve super-resolutions of 0.1" by deconvolving RV Boo with a point-spread function (PSF) derived from an unresolved star. We tentatively resolve RV Boo into a 0.16" FWHM extension at a position angle of 120 degrees. At a distance of 390(+250)(-100) pc, this corresponds to a FWHM of 60(+40)(-15) AU. We measure a total flux at 9.8 um of 145+-24 Jy for the disk and star. Based on a dust thermal emission model for the observed IR spectral energy distribution and the 9.8 um AO image, we derive a disk dust mass of 1.6x10^-6 Msun and an inclination of 30 to 45 degrees from edge-on. We discuss whether the dust disk observed around RV Boo is an example of the early stages in the formation of asymmetric structure in planetary nebula.
Published: 2005
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56. Adaptive Optics Nulling Interferometric Constraints on the Mid-Infrared Exozodiacal Dust Emission around Vega

Author: William F. Hoffmann, Patrick C. McGuire, James Roger P. Angel, Guido Brusa, Matthew A. Kenworthy, W. M. Liu, Francois Wildi, Michael Lloyd-Hart, Doug Miller, and Philip M. Hinz
Subjects: Physics, Solar System, Zodiacal light, Astrophysics (astro-ph), Exozodiacal dust, Vega, Mid infrared, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Interferometry, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Secondary mirror, Adaptive optics, Astrophysics::Galaxy Astrophysics
Abstract: We present the results of mid-infrared nulling interferometric observations of the main-sequence star alpha Lyr (Vega) using the 6.5 m MMT with its adaptive secondary mirror. From the observations at 10.6 microns, we find that there is no resolved emission from the circumstellar environment (at separations greater than 0.8 AU) above 2.1% (3 sigma limit) of the level of the stellar photospheric emission. Thus, we are able to place an upper limit on the density of dust in the inner system of 650 times that of our own solar system's zodiacal cloud. This limit is roughly 2.8 times better than those determined with photometric excess observations such as those by IRAS. Comparison with far-infrared observations by IRAS shows that the density of warm dust in the inner system (< 30 AU) is significantly lower than cold dust at larger separations. We consider two scenarios for grain removal, the sublimation of ice grains and the presence of a planetary mass "sweeper." We find that if sublimation of ice grains is the only removal process, a large fraction (> 80%) of the material in the outer system is ice., 11 pages, 1 figure, Accepted to The Astrophysical Journal Letters
Published: 2004
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57. High‐Resolution Images of Orbital Motion in the Trapezium Cluster: First Scientific Results from the Multiple Mirror Telescope Deformable Secondary Mirror Adaptive Optics System1

Author: Manny Montoya, R. G. Allen, Nick Siegler, R. Sosa, Mario Rascon, Armando Riccardi, Dylan Curley, Donald W. McCarthy, Hubert M. Martin, Piero Salinari, Francois Wildi, Michael Lloyd-Hart, Don Fisher, Doug Miller, Matt Rademacher, Roger Angel, Wolfgang J. Duschl, Guido Brusa, and Laird M. Close
Subjects: Physics, 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Brown dwarf, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, law.invention, Telescope, Stars, Space and Planetary Science, law, Sky, 0103 physical sciences, Orbital motion, Secondary mirror, Low Mass, Adaptive optics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, media_common
Abstract: We present the first scientific images obtained with a deformable secondary mirror adaptive optics (AO) system. We utilized the 6.5 m Multiple Mirror Telescope adaptive optics system to produce high-resolution (FWHM ¼ 0>07) near-infrared (1.6 lm) images of the young (� 1 Myr) Orion Trapezium � 1 Ori cluster members. A combination of high spatial resolution and high signal-to-noise ratio allowed the positions of these stars to be measured to within � 0>003 accuracies. We also present slightly lower resolution (FWHM � 0>085) images from Gemini with the Hokupa‘a AO system as well. Including previous speckle data from Weigelt et al., we analyze a 6 yr baseline of high-resolution observations of this cluster. Over this baseline we are sensitive to relative proper motions of only � 0>002 yr � 1 (4.2 km s � 1 at 450 pc). At such sensitivities we detect orbital motion in the very tight � 1 Ori B2-B3 (52 AU separation) and � 1 Ori A1-A2 (94 AU separation) systems. The relative velocity in the � 1 Ori B2-B3 system is 4:2 � 2: 1k m s � 1 . We observe 16:5 � 5: 7k m s � 1 of relative motion in the � 1 Ori A1-A2 system. These velocities are consistent with those independently observed by Schertl et al. with speckle interferometry, giving us confidence that these very small (� 0>002 yr � 1 ) orbital motions are real. All five members of the � 1 Ori B system appear likely gravitationally bound (B2-B3 is moving at � 1.4 km s � 1 in the plane of the sky with respect to B1, where Vesc � 6k m s � 1 for the B group). The very lowest mass member of the � 1 Ori B system (B4) has K 0 � 11:66 and an estimated mass of � 0.2 M� . Very little motion (4 � 15 km s � 1 ) of B4 was detected with respect to B1 or B2; hence, B4 is possibly part of the � 1 Ori B group. We suspect that if this very low mass member is physically associated, it most likely is in an unstable (nonhierarchical) orbital position and will soon be ejected from the group. The � 1 Ori B system appears to be a good example of a star formation ‘‘ minicluster,’’ which may eject the lowest mass members of the cluster in the near future. This ‘‘ ejection ’’ process could play a major role in the formation of low-mass stars and brown dwarfs. Subject headings: binaries: general — instrumentation: adaptive optics — stars: evolution — stars: formation — stars: low-mass, brown dwarfs On-line material: color figures
Published: 2003
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58. Mid-Infrared Imaging of the Post-Asymptotic Giant Branch Star AC Herculis with the Multiple Mirror Telescope Adaptive Optics System

Author: Phil Hinz, Michael Lloyd-Hart, John H. Bieging, Doug Miller, Don Fisher, Beth Biller, Guido Brusa, Francois Wildi, Laird M. Close, William F. Hoffmann, and Roger Angel
Subjects: Physics, media_common.quotation_subject, Strehl ratio, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, 010309 optics, Stars, Full width at half maximum, 13. Climate action, Space and Planetary Science, Sky, 0103 physical sciences, Calibration, Asymptotic giant branch, Circumbinary planet, Adaptive optics, 010303 astronomy & astrophysics, media_common
Abstract: We utilized the MMT's unique deformable secondary adaptive optics system to produce high-resolution (FWHM=0.3"), very high Strehl mid-infrared (9.8, 11.7 & 18 micron) images of the post-AGB star AC Her. The very high (98+/-2%) Strehls achieved with Mid-IR AO led naturally to an ultra-stable PSF independent of airmass, seeing, or location on the sky. We find no significant difference between AC Her's morphology and our unresolved PSF calibration stars (mu UMa & alpha Her) at 9.8, 11.7, & 18 microns. Our current observations do not confirm any extended Mid-IR structure around AC Her. These observations are in conflict with previously reported Keck (seeing-limited) 11.7 and 18 micron images which suggested the presence of a resolved ~0.6" edge-on circumbinary disk. We conclude that AC Her has no extended Mid-IR structure on scales greater than 0.2" (R
Published: 2003
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59. HIRES: the high resolution spectrograph for the E-ELT

Author: David Henry, Didier Queloz, Alexandre Cabral, R. Rebolo Lopez, Filippo Maria Zerbi, François Bouchy, A. Marconi, David F. Buscher, Stefano Cristiani, Martyn Wells, Kevin Heng, Roberto Maiolino, L. Vanzi, A. P. Hatzes, Klaus G. Strassmeier, Tim Morris, Patrick Petitjean, Ernesto Oliva, Mário J. P. F. G. Monteiro, Francesco Pepe, X. Bonfils, P. Figueira, Livia Origlia, Johan P. U. Fynbo, Pasquier Noterdaeme, Garik Israelian, A. Quirrenbach, C. Allende Prieto, Luca Valenziano, Carlos Martins, Manuela Zoccali, Nikolai Piskunov, Jose Luis Rasilla, P. Dimarcantonio, Stéphane Udry, Nuno C. Santos, Marco Riva, C. Lovis, Phil Rees, Ian Parry, Andrea Chiavassa, Eric Stempels, Alastair Basden, I. Boisse, Bengt Gustafsson, Francois Wildi, Graham J. Murray, Thomas H. Puzia, I. Di Varano, Ansgar Reiners, Oleg Kochukhov, Martin G. Haehnelt, 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), and Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Stars, ComputingMilieux_THECOMPUTINGPROFESSION, [SDU]Sciences of the Universe [physics], Planet, Astronomy, High resolution, Astrophysics, Spectrograph
Abstract: International audience; The current instrumentation plan for the E-ELT foresees a High Resolution Spectrograph conventionally indicated as HIRES. Shaped on the study of extra-solar planet atmospheres, Pop-III stars and fundamental physical constants, HIRES is intended to embed observing modes at high-resolution (up to R=150000) and large spectral range (from the blue limit to the K band) useful for a large suite of science cases that can exclusively be tackled by the E-ELT. We present in this paper the solution for HIRES envisaged by the "HIRES initiative", the international collaboration established in 2013 to pursue a HIRES on E-ELT.
Published: 2014
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60. The SPHERE IFS at work

Author: J. L. Lizon, Silvano Desidera, Reinhold J. Dorn, Daniela Fantinel, Bernardo Salasnich, Norbert Hubin, Francois Wildi, Gert Finger, Enrico Cascone, Dino Mesa, Massimo Turatto, David Mouillet, Luigi Lessio, Anne-Lise Maire, Salvo Scuderi, V. Decaprio, A. Zurlo, Riccardo Claudi, Kjetil Dohlen, Patrick Bruno, M. Kasper, Pascal Puget, Enrico Giro, Andrea Baruffolo, Jean-Luc Beuzit, and R. G. Gratton
Subjects: Physics, business.industry, Near-infrared spectroscopy, Astrophysics::Instrumentation and Methods for Astrophysics, Polarimetry, Field of view, Astrophysics::Cosmology and Extragalactic Astrophysics, Exoplanet, law.invention, Optics, Integral field spectrograph, law, Planet, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, business, Coronagraph, Spectrograph, Astrophysics::Galaxy Astrophysics
Abstract: SPHERE is an extrasolar planet imager whose goal is to detect giant extrasolar planets in the vicinity of bright stars and to characterize them through spectroscopic and polarimetric observations. It is a complete system with a core made of an extreme-Adaptive Optics (AO) turbulence correction, a pupil tracker and NIR and Visible coronagraph devices. At its back end, a differential dual imaging camera and an integral field spectrograph (IFS) work in the Near Infrared (NIR) (0.95 ≤λ≤2.32 μm) and a high resolution polarization camera covers the visible (0.6 ≤λ≤0.9 μm). The IFS is a low resolution spectrograph (R~50) operates in the near IR (0.95≤λ≤1.6 μm), an ideal wavelength range for the detection of planetary features, over a field of view of about 1.7 x 1.7 square arcsecs. Form spectra it is possible to reconstruct monochromatic images with high contrast (10 -7 ) and high spatial resolution, well inside the star PSF. In this paper we describe the IFS, its calibration and the results of several performance which IFS underwent. Furthermore, using the IFS characteristics we give a forecast on the planetary detection rate.
Published: 2014
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61. High contrast polarimetry in the infrared with SPHERE on the VLT

Author: Maud Langlois, David Le Mignant, H. M. Schmid, L. Lizon, Arthur Vigan, Alice Zurlo, J. Mili, Jean-François Sauvage, J.-P. Puget, C. Moutou, A. Boccaletti, David Mouillet, Markus Feldt, Anne Costille, Kjetil Dohlen, Francois Wildi, Norbert Hubin, Jean-Luc Beuzit, F. Madec, L. Gluck, Reinhold J. Dorn, M. Kasper, M. Carle, 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), 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), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), 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), ONERA, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, 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), and Université de Genève = University of Geneva (UNIGE)
Subjects: Physics, Infrared, Polarimetry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Polarization (waves), Exoplanet, Stars, Speckle pattern, Integral field spectrograph, 13. Climate action, Planet, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract: International audience; The instrument SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch), recently installed on the VLT-UT3, aims to detected and characterize giant extra-solar planets and the circumstellar environments in the very close vicinity of bright stars. The extreme brightness contrast and small angular separation between the planets or disks and their parent stars have so far proven very challenging. SPHERE will meet this challenge by using an extreme AO, stellar coronagraphs, an infrared dual band and polarimetric imager called IRDIS, an integral field spectrograph, and a visible polarimetric differential imager called ZIMPOL. Polarimetry allows a separation of the light coming from an unpolarized source such as a star and the polarized source such as a planet or protoplanetary disks. In this paper we present the performance of the infrared polarimetric imager based on experimental validations performed within SPHERE before the preliminary acceptance in Europe. We report on the level of instrumental polarization in the infrared and its calibration limit. Using differential polarimetry technique, we quantify the level of speckle suppression, and hence improved sensitivity in the context of imaging extended stellar environments.
Published: 2014
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62. Sphere extreme AO control scheme: final performance assessment and on sky validation of the first auto-tuned LQG based operational system (Orale)

Author: Caroline Kulcsár, Denis Perret, J. L. Beuzit, Arnaud Sevin, David Mouillet, Thierry Fusco, Sylvain Rochat, Arthur Vigan, M. Kasper, Jean-François Sauvage, Jean-Marc Conan, Francois Wildi, A. Barrufolo, Pascal Puget, Kjetil Dohlen, Henri-François Raynaud, Bernardo Salasnich, Anne Costille, Christian Soenke, Cyril Petit, Marcos Suarez, ONERA - The French Aerospace Lab [Châtillon], ONERA, 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), Observatoire de Paris - Site de Paris (OP), 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), ESO, Physics Department [Garching], Technical University of Munich (TUM)-Technical University of Munich (TUM), 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), University of Geneva, Genève, Laboratoire Charles Fabry / Spim, Laboratoire Charles Fabry (LCF), Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS), ONERA-Université Paris Saclay (COmUE), 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), 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), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 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)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])
Subjects: Physics, ADAPTIVE OPTICS, CONTROL, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Operability, HIGH CONTRAST IMAGING, Optimal estimation, business.industry, Kalman filter, Linear-quadratic-Gaussian control, 01 natural sciences, Deformable mirror, 010309 optics, Optics, 13. Climate action, Robustness (computer science), Control theory, Integrator, 0103 physical sciences, Adaptive optics, business, 010303 astronomy & astrophysics
Abstract: International audience; The SPHERE (Spectro-Polarimetry High-contrast Exoplanet Research) instrument is an ESO project aiming at the direct detection of extra-solar planets. SPHERE has been successfully integrated and tested in Europe end 2013 and has been re-integrated at Paranal in Chile early 2014 for a first light at the beginning of May. The heart of the SPHERE instrument is its eXtreme Adaptive Optics (XAO) SAXO (SPHERE AO for eXoplanet Observation) subsystem that provides extremely high correction of turbulence and very accurate stabilization of images for coronagraphic purpose. However, SAXO, as well as the overall instrument, must also provide constant operability overnights, ensuring robustness and autonomy. An original control scheme has been developed to satisfy this challenging dichotomy. It includes in particular both an Optimized Modal Gain Integrator (OMGI) to control the Deformable Mirror (DM) and a Linear Quadratic Gaussian (LQG) control law to manage the tip-tilt (TT) mirror. LQG allows optimal estimation and prediction of turbulent angle of arrival but also of possible vibrations. A specific and unprecedented control scheme has been developed to continuously adapt and optimize LQG control ensuring a constant match to turbulence and vibrations characteristics. SPHERE is thus the first operational system implementing LQG, with automatic adjustment of its models. SAXO has demonstrated performance beyond expectations during tests in Europe, in spite of internal limitations. Very first results have been obtained on sky last May. We thus come back to SAXO control scheme, focusing in particular on the LQG based TT control and the various upgrades that have been made to enhance further the performance ensuring constant operability and robustness. We finally propose performance assessment based on in lab performance and first on sky results and discuss further possible improvements.
Published: 2014
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63. SPIRou @CFHT: design of the instrument control system

Author: Francesco Pepe, Vladimir Reshetov, L. Parès, David Loop, Francois Wildi, François Bouchy, François Moreau, Patrick Rabou, Sébastien Baratchart, Jennifer Dunn, Étienne Artigau, F. Dolon, Olivier Hernandez, Gregory Barrick, James N. Thomas, Shiang-Yu Wang, Marie Larrieu, Xavier Delfosse, M. Dupieux, René Doyon, Alexandre Fonteneau, Driss Kouach, Chi-Hung Yan, Gérard Gallou, Jean-François Donati, Tom Vermeulen, Simon Thibault, and Philippe Vallée
Subjects: Velocimeters, Instrument control, Velocity measurement, Computer science, CFHT, Tip-tilt, Fast guiding, Stars, Control-command, Thermal control, law.invention, Telescope, High precision, Mauna kea, Planet, law, Control system, Near-IR, Focus (optics), Spectropolarimetry, Algorithms, Remote sensing
Abstract: SPIRou is a near-IR (0.98-2.35μm), echelle spectropolarimeter / high precision velocimeter being designed as a next-generation instrument for the 3.6m Canada-France-Hawaii Telescope on Mauna Kea, Hawaii, with the main goals of detecting Earth-like planets around low-mass stars and magnetic fields of forming stars. The unique scientific and technical capabilities of SPIRou are described in a series of eight companion papers. In this paper, the means of controlling the instrument are discussed. Most of the instrument control is fairly normal, using off-the-shelf components where possible and reusing already available code for these components. Some aspects, however, are more challenging. In particular, the paper will focus on the challenges of doing fast (50 Hz) guiding with 30 mas repeatability using the object being observed as a reference and on thermally stabilizing a large optical bench to a very high precision (∼1 mK)., Software and Cyberinfrastructure for Astronomy II, July 1-4, 2012, Amsterdam, Netherlands, Series: Proceedings of SPIE
Published: 2012

64. Optical fibers for precise radial velocities: an update

Author: Francesco Pepe, Bruno Chazelas, and Francois Wildi
Subjects: Optical fiber, Etendue, Computer science, business.industry, Laser, 01 natural sciences, law.invention, 010309 optics, Optics, law, 0103 physical sciences, Calibration, Fiber, business, 010303 astronomy & astrophysics, Spectrograph, Beam (structure), Fabry–Pérot interferometer
Abstract: For the PRV instrument using simultaneous calibration technique such as with sources like thorium lamps, Fabry Perot Etalons or laser comb, it is essential that the instrument stays stable between the wavelength calibration frame and the actual scientific measurement. These instruments are usually in pressure and temperature controlled environments for example under vacuum. However this is not sufficient to reach the instrumental stability required to get to precision level of the ms -1 and below required to build the next generation PRV instruments. Another requirement is an as constant as possible illumination of the spectrograph to stabilize the line profile of the instrument. To achieve this, it is necessary to use a device that will scramble the light coming from the star to mitigate the effects of the atmosphere. In addition this device should not increase significantly the beam etendue, which is already a technological challenge for large telescopes. The common solution to this problem is to use optical fibers. Historically the solution has been to use circular fibers as they were the only one available. Recently for other purposes non-circular fibers have been developed and made available. They have been tested, and present an important improvement in the scrambling over the circular fibers. We will present in this paper the properties of the octagonal fibers used for the HARPS-N2 instrument and the achieved performance of its fiber train.
Published: 2012
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65. SPHERE / ZIMPOL: characterization of the FLC polarization modulator

Author: Andreas Bazzon, A. Pavlov, Kjetil Dohlen, David Mouillet, Menno de Haan, Bernardo Salasnich, Jean-Luc Beuzit, Johan Pragt, Ronald Roelfsema, D. Gisler, Mark Downing, Hans Martin Schmid, Eddy Elswijk, and Francois Wildi
Subjects: Physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Polarimetry, Polarimeter, Polarization (waves), 01 natural sciences, Exoplanet, 010309 optics, Wavelength, Optics, Modulation, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, business, 010303 astronomy & astrophysics, Data reduction, Remote sensing
Abstract: ZIMPOL is an imaging polarimeter for the high contrast SPHERE/VLT "planet finder" instrument using fast polarization modulation and demodulating CCD detectors. The polarimetric performance of the ZIMPOL instrument depends on the polarimetric alignment and quality of the polarization components. This paper gives an overview on the polarimetric concept and the calibration plan of ZIMPOL. We discuss in particular the alignment of the polarimetric calibration components and the polarimetric properties of the ferro electric liquid crystal (FLC) modulator package used in ZIMPOL. Our measurements demonstrate the good broad band performance of the modulator. Faint targets like extra solar planets require mainly a high polarimetric efficiency while for detailed studies of bright targets a good characterization of the modulator package is essential. Therefore we quantify in detail the wavelength dependence of the polarimetric efficiency and the cross talk effects which have to be taken into account in the calibration and data reduction process of high S/N measurements.© (2012) COPYRIGHT Society of Photo Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Published: 2012
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66. The IFS of SPHERE: integration and laboratory performances

Author: Pascal Puget, Norbert Hubin, Enrico Giro, Andrea Baruffolo, Anne Costille, Silvano Desidera, Riccardo Claudi, Luigi Lessio, J.-L. Lizon, Dino Mesa, Gert Finger, Salvo Scuderi, Daniela Fantinel, U. Anselmi, Massimo Turatto, R. G. Gratton, Francois Wildi, Reinhold J. Dorn, Enrico Cascone, E. Sant'Ambrogio, J. L. Beuzit, Pietro Bruno, Bernardo Salasnich, V. De Caprio, M. Kasper, and K. Dohlen
Subjects: Microlens, Physics, business.industry, Near-infrared spectroscopy, Astronomy, Field of view, 01 natural sciences, 7. Clean energy, Exoplanet, law.invention, 010309 optics, Optics, Integral field spectrograph, Planet, law, 0103 physical sciences, business, 010303 astronomy & astrophysics, Spectrograph, Coronagraph
Abstract: SPHERE is an exo-solar planet imager, which goal is to detect giant exo-solar planets in the vicinity of bright stars and to characterize them through spectroscopic and polarimetric observations. It is a complete system with a core made of an extreme-Adaptive Optics (AO) turbulence correction, pupil tracker and NIR and Visible coronagraph devices. At its back end, a differential dual imaging camera and an integral field spectrograph (IFS) work in the Near Infrared (NIR) Y, J, H and Ks bands (0.95≤λ≤2.32 μm) and a high resolution polarization camera covers the visible (0.6≤λ≤0.9 μm). The IFS is a low resolution spectrograph (R~50) which works in the near IR (0.95≤λ≤1.6 μm), an ideal wavelength range for the detection of planetary features. The IFS is based on a new conception microlens array (BIGRE) of 145X145 lenslets designed to reduce as low as possible the contrast. The IFU will cover a field of view of about 1.7 x 1.7 square arcsecs reaching a contrast of 10 -7 , giving an high contrast and high spatial resolution "imager" able to search for planet well inside the star PSF. In the last year it has been integrated onto the huge optical bench of SPHERE and fully tested.
Published: 2012
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67. The SPHERE XAO system SAXO: integration, test, and laboratory performance

Author: J. L. Beuzit, Marcos Suarez, Arnaud Sevin, Pierre Baudoz, D. Perret, T. Fusco, Philippe Feautrier, David Mouillet, Jean Luc Gach, C. Petit, M. Kasper, Norbert Hubin, J.-F. Sauvage, Christian Soenke, Enrico Fedrigo, Emmanuel Hugot, Kjetil Dohlen, Jean-Christophe Sinquin, Tristan Buey, Anne Costille, Francois Wildi, Pascal Puget, Julien Charton, 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), Haute résolution angulaire en astrophysique, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Scientific instrument, Physics, Wavefront, Integration testing, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Polarimetry, 01 natural sciences, 7. Clean energy, Exoplanet, 010309 optics, 13. Climate action, Planet, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, Aerospace engineering, Adaptive optics, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Host (network), Remote sensing
Abstract: Direct detection and spectral characterization of extra-solar planets is one of the most exciting and challenging areas in modern astronomy due to the very large contrast between the host star and the planet at very small angular separations. SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research in Europe) is a second-generation instrument for the ESO VLT dedicated to this scientific objective. It combines an extreme adaptive optics system, various coronagraphic devices and a suite of focal instruments providing imaging, integral field spectroscopy and polarimetry capabilities in the visible and near-infrared spectral ranges. The extreme Adaptive Optics (AO) system, SAXO, is the heart of the SPHERE system, providing to the scientific instruments a flat wavefront corrected from all the atmospheric turbulence and internal defects. We present an updated analysis of SAXO assembly, integration and performance. This integration has been defined in a two step process. While first step is now over and second one is ongoing, we propose a global overview of integration results. The main requirements and system characteristics are briefly recalled, then each sub system is presented and characterized. Finally the full AO loop first performance is assessed. First results demonstrate that SAXO shall meet its challenging requirements.
Published: 2012
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68. Optical design and test of the BIGRE-based IFS of SPHERE

Author: Jacopo Antichi, Bernardo Salasnich, V. De Caprio, Dino Mesa, Luigi Lessio, Enrico Cascone, Daniela Fantinel, J. L. Beuzit, Francois Wildi, Riccardo Claudi, Kjetil Dohlen, Norbert Hubin, Salvo Scuderi, Pascal Puget, U. Anselmi, M. Kasper, Silvano Desidera, Pietro Bruno, R. G. Gratton, and Enrico Giro
Subjects: Physics, Microlens, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Lenslet, law.invention, Telescope, Integral field spectrograph, Cardinal point, Optics, Sampling (signal processing), law, Observatory, Focal length, Astrophysics::Earth and Planetary Astrophysics, business
Abstract: During the last months IFS, is the Integral Field Spectrograph for SPHERE, devoted to the search of exoplanets has been integrated in the clean room of Padova Observatory. The design of IFS is based on a new concept of double microlens array sampling the focal plane. This device named BIGRE consists of a system made of two microlens arrays with different focal lengths and thickness equal to the sum of them and precisely aligned each other. Moreover a mask has been deposited on the first array to produce a field stop for each lenslet, and a second mask is located on the intermediate pupil of the IFS to provide an aperture stop. After characterization of a previous prototype of BIGRE in the visible range, now the first measurements of the performances of the device in the IR range have been obtained on the instrument that will be mounted at the VLT telescope. These tests confirmed that specifications and properties of the prototype are met by state of the art on optics microlens manufacturing.
Published: 2011
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69. The performance of the new Fabry-Perot calibration system of the radial velocity spectrograph HARPS

Author: Francois Wildi, Christophe Lovis, Gaspare Lo Curto, Bruno Chazelas, and Francesco Pepe
Subjects: Physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, 01 natural sciences, 010309 optics, Radial velocity, Interferometry, Optics, Planet, Observatory, 0103 physical sciences, Astronomical interferometer, Calibration, Astrophysics::Earth and Planetary Astrophysics, business, 010303 astronomy & astrophysics, Spectrograph, Noise (radio)
Abstract: The Observatory of Geneva has designed, built and tested in collaboration with ESO a calibrator system based on a Fabry-Perot (FP) interferometer to explore its potential in the calibration of radial velocity (RV) spectrographs. Today, the RV technique has pushed th e planet detection limits down to s uper-earths but the reach the precision required to detect earth-like planets it is necessary to reach a precision around 1cm s -1 . While a significant part of the error budget is the incompressible photon noise, another part is the noise in the wavelength calibration of the spectrograph. It is to address this problem that we have developed this new device. We have obtained exciting results with the calibrator system demonstrated 10 cm s -1 stability over one night and 1 m s over 60 days. By further improving the injection system we are aiming at a 1 m s -1 repeatability over the long term. Keywords: extra-solar planets, radial velocity m easurement, high resolution spectrograph
Published: 2011
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70. The performance of the calibration module for SPHERE

Author: Rene Dubosson, H. M. Schmid, David Mouillet, Jean-Luc Beuzit, Bernard Michaud, Kjetil Dohlen, Michel Crausaz, and Francois Wildi
Subjects: Physics, business.industry, System of measurement, Near-infrared spectroscopy, Astrophysics::Instrumentation and Methods for Astrophysics, Polarimeter, Integral field spectrograph, Optics, Calibration, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Multi-band device, Adaptive optics, business, Spectrograph, Remote sensing
Abstract: One of the main challenges to obtain the contrast of >15mag targeted by the extra-solar planet imager SPHERE lies in the calibration of all the different elements participating in the final performance. The Adaptive Optics (AO) system and its three embedded loops, the coronagraphs, the Near Infrared (NIR) dual band imager, the NIR integral field spectrograph, the NIR spectrograph, the visible high accuracy polarimeter and the visible imager all require sophisticated calibration. The calibration process relies on a specific complex calibration module that provides the different sources across the spectrum (500-2320nm) with the stabilities and precisions required and positions them when the need to be. This calibration module has just passed all verification tests and its performance is now well characterized. Its design and performance is the object of this article.
Published: 2010
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71. SAXO, the eXtreme Adaptive Optics System of SPHERE: overview and calibration procedure

Author: Norbert Hubin, J.-F. Sauvage, Pierre Baudoz, Julien Charton, Arnaud Sevin, C. Petit, M. Suarez Valles, David Mouillet, Serge Meimon, M. Kasper, Kjetil Dohlen, Francois Wildi, Anne Costille, Tristan Buey, J. L. Beuzit, T. Fusco, Enrico Fedrigo, and Rabou P
Subjects: Physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Measure (physics), Direct imaging, Exoplanet, Identification (information), Adaptive system, Calibration, Astrophysics::Earth and Planetary Astrophysics, Aerospace engineering, Adaptive optics systems, business, Adaptive optics, Remote sensing
Abstract: The direct imaging of exoplanet is a challenging goal of todays astronomy. The light transmitted by exoplanet atmosphere is of a great interest as it may witness for life sign. SPHERE is a second generation instrument for the VLT, dedicated to exoplanet imaging, detection, and characterisation. SPHERE is a global project of an European consortium of 11 institutes from 5 countries. We present here the state of the art of the AIT of the Adaptive Optics part of the instrument. In addition we present fine calibration procedures dedicated to eXtreme Adaptive Optics systems. First we emphasized on vibration and turbulence identification for optimization of the control law. Then, we describe a procedure able to measure and compensate for NCPA with a coronagraphic system.
Published: 2010
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72. The differential tip-tilt sensor of SPHERE

Author: Markus Kasper, Kjetil Dohlen, David Mouillet, Julien Charton, Francois Wildi, Jean-Luc Beuzit, Reinhold J. Dorn, Jean-Louis Lizon, Norbert Hubin, Markus Felt, Thierry Fusco, Pascal Puget, Pierre Baudoz, and Andrea Barrufolo
Subjects: Physics, Wavefront, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Exoplanet, law.invention, Cardinal point, Tilt sensor, Optics, law, Planet, Position (vector), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Adaptive optics, business, Coronagraph
Abstract: The SPHERE instrument aims at detecting giant extrasolar planets in the vicinity of bright stars. Such a challenging goal requires the use of a high performance Adaptive Optics (AO) system, a coronagraphic device to cancel out the flux coming from the star itself, and smart focal plane techniques to calibrate residual uncorrected turbulent and/or static wavefronts. Inside the adaptive optic system, a specific tool is developed in SPHERE to ensure that the star is always well centered on the coronagraph. This tool called Differential Tip-Tilt Sensor (DTTS) measures the position of the star at the same wavelength than the science instruments. It is located very close to the focal plane to minimize drifts between DTTS and the coronagraph. After describing the DTTS, we will describe the tests and laboratory results on stability measurement of the DTTS; stability which is crucial for SPHERE performance.
Published: 2010
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73. Along the path towards extremely precise radial velocity measurements

Author: Jonay I. González-Hernández, Bruno Chazelas, G. Ihle, Theodor W. Hänsch, Tobias Wilken, P. Sinclaire, Ronald Holzwarth, Gerardo Avila, Alex Segovia, Massimiliano Esposito, Rafael Rebolo, Christophe Lovis, Thomas Udem, Tilo Steinmetz, Gaspare Lo Curto, Francois Wildi, Luca Pasquini, Francesco Pepe, and Antonio Manescau
Subjects: Physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Laser, Exoplanet, law.invention, Telescope, Radial velocity, Wavelength, Optics, law, Planet, Calibration, Astrophysics::Earth and Planetary Astrophysics, business, Spectrograph
Abstract: In the last six years, thanks to the very high radial velocity precision of the HARPS spectrograph, it was possible to detect 21 out of the 30 super-Earth (extrasolar planets masses below 20 times the mass of the Earth) discovered up to date. The radial velocity precision of the instrument is estimated around 80 cm/s on a single measurement. The main instrumental limitations are the wavelength calibration and the stability of the light injection. We address both factors and present the results of recent tests on the HARPS spectrograph. We have identified the laser frequency comb as the ideal wavelength calibrator, due to the width, density and flux of the lines, and to its intrinsic stability. The results from the recent tests that we performed on HARPS are encouraging. The accurate guiding of the telescope is critical to maintain a stable light distribution at the injection stage, where the light is sent into the spectrograph entrance fiber. To pursue this goal we are testing a secondary guiding system which is able to apply the guiding corrections twenty times faster than the primary guiding system.
Published: 2010
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74. New scramblers for precision radial velocity: square and octagonal fibers

Author: François Bouchy, S. Perruchot, Francesco Pepe, Francois Wildi, Gerardo Avila, and Bruno Chazelas
Subjects: Radial velocity, Optics, Materials science, Optical fiber, business.industry, law, Physics::Optics, Near and far field, Fiber, business, Square (algebra), Scrambling, law.invention
Abstract: One of the remaining limitation of the precise radial velocity instruments is the imperfect scrambling produced by the circular fibers. We present here experimental studies on new optical fibers aiming at an improvement of the scrambling they provide. New fibers shapes were tested: square and octagonal. Measurements have been performed of the scrambling performances of these fibers in the near field as well FRD measurements. These fibers show extremely promising performances in the near field scrambling: an improvement of a factor 5 to 10 compared to the circular fiber. They however show some strange behavior in the far field that need to be understood.
Published: 2010
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75. A Fabry-Perot calibrator of the HARPS radial velocity spectrograph: performance report

Author: Francesco Pepe, Ch. Lovis, Francois Wildi, Gaspare Lo Curto, and Bruno Chazelas
Subjects: Physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Exoplanet, Radial velocity, Interferometry, Optics, Observatory, Planet, Calibration, Astrophysics::Earth and Planetary Astrophysics, business, Spectrograph, Fabry–Pérot interferometer
Abstract: The radial velocity (RV) technique has pushed the planet detection limits down to super-earths. To reach the precision required to detect ear th-like planets it is necessary to reach a precision around 1cm.s -1 . Part of the error budget is due to noise in the wavelength calibration of the spectrograph. The Observatory of Geneva has designed, built and tested in collaboration with ESO a calibrator syst em based on a Fabry-Perot interferometer to explore its potential to improve the wavelength calibration of RV spectr ographs. We have obtained exciting results with the calibrator system demonstrated 10 cm s -1 stability over one night. By further improving the injection system we are aiming at a 1 m s -1 repeatability over the long term. Keywords: extra-solar planets, radial velocity m easurement, high resolution spectrograph 1. INTRODUCTION The radial velocity (RV) technique is so far the most powerful extra-solar planets discovery tool. With the current precision achieved by RV of 69 cm.s
Published: 2010
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76. Impact of calibration on extrasolar planets direct imaging with IRDIS, the infrared dual-imaging camera and spectrograph for SPHERE

Author: Francois Wildi, Kjetil Dohlen, Arthur Vigan, Maud Langlois, David Mouillet, Anthony Boccaletti, C. Moutou, 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 ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), 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), 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), Université de Genève = University of Geneva (UNIGE), 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), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Near-infrared spectroscopy, Polarimetry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Optical polarization, 02 engineering and technology, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, Exoplanet, 010309 optics, Optics, Planet, 0103 physical sciences, Data analysis, Astrophysics::Earth and Planetary Astrophysics, 0210 nano-technology, business, Spectrograph, Astrophysics::Galaxy Astrophysics, Long-slit spectroscopy
Abstract: International audience; The detection and characterization of extrasolar planets by direct imaging is becoming more and more promising with the preparation of dedicated high-contrast instruments and the help of new data analysis techniques. SPHERE (Spectro-Polarimetric High-contrast imager for Exoplanets REsearch) is currently being developed as part of the second generation instruments of the ESO-VLT. IRDIS, one of the SPHERE subsystems, will provide dual-band imaging with several filter pairs covering the near-infrared from 0.95 to 2.3 microns, among with other observing modes such as long slit spectroscopy and infrared polarimetry. This paper describes the instrument performances and the impact of instrumental calibrations on finding and characterizing extrasolar planets, and on observing strategies. It discusses constraints to achieve the required contrast of ~106 within few hours of exposure time.
Published: 2010
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77. Calibration of high accuracy radial velocity spectrographs: beyond the Th-Ar lamps

Author: Gaspare Lo Curto, Ronald Holzwarth, Thomas Udem, Antonio Manescau, Francesco Pepe, Tilo Stenimetz, Tobias Wilken, Bruno Chazelas, Christophe Lovis, Theodor W. Hänsch, Luca Pasquini, and Francois Wildi
Subjects: Physics, business.industry, Instrumentation, First light, law.invention, Radial velocity, Telescope, Interferometry, Optics, Observatory, law, Calibration, business, Spectrograph
Abstract: Since its first light in 2003, the HARPS radial velocity spectrograph (RVS) has performed exquisitely well on the 3.6m ESO telescope at La Silla Observatory (Chile). It now routinely exhibits a measurement noise of 0.5 m/s or 1.7 10-9 on a relative scale. Despite innovative work by Lovis and colleagues [14] to improve the accuracy obtained with the calibration lamps used, there is evidence that still better performance could be achieved by using more stable wavelength standards. In this paper, we present two methods are aim at overcoming the shortcoming of present day calibrators and that could satisfy the need for a cm/s -level calibrator like we are planning on using on the 2nd generation instruments at the VLT and on the ELT instrumentation. A temperature-stabilized Fabry-Perot interferometer has the promise of being stable to a few cm/s and has very uniform line levels and spacings, while a laser comb has already achieved a precision better than 15 cm/s, despite using only one of the 72 orders of the spectrographs.
Published: 2009
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78. SPHERE: the VLT planet imager in the post FDR phase

Author: Thomas Henning, A. Pavlov, Philippe Feautrier, Anthony Boccaletti, Francois Wildi, Pierre Baudoz, Eric Stadler, Maud Langlois, Michel Saisse, Johan Pragt, Hans Martin Schmid, Thierry Fusco, Markus Feldt, Raffaele Gratton, Patrick Rabou, Kjetil Dohlen, Julien Charton, Cyril Petit, Pascal Puget, Rainer Lenzen, Stéphane Udry, Massimo Turatto, Riccardo Claudi, Ronald Roelfsema, Claire Moutou, Rens Waters, Andrea Baruffolo, Jean-Luc Beuzit, Norbert Hubin, Anne-Marie Lagrange, Lyu Abe, David Mouillet, Farrokh Vakili, Markus Kasper, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris
Subjects: Test strategy, Physics, medicine.medical_specialty, Polarimetry, Phase (waves), Astronomy, Field of view, Exoplanet, Spectral imaging, Planet, medicine, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Design review
Abstract: SPHERE, the ESO extra-solar planet imager for the VLT is aimed at the direct detection and spectral characterization of extra-solar planets. Its whole design is optimized towards reaching the highest contrast in a limited field of view and at short distances from the central star. SPHERE has passed its Final Design Review (FDR) in December 2008 and it is in the manufacturing and integration phase. We review the most challenging specifications and expected performance of this instrument; then we present the latest stage of the design chosen to meet the specifications, the progress in the manufacturing as well as the integration and test strategy to insure gradual verification of performances at all levels.
Published: 2009
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79. Calibration and data reduction for planet detection with SPHERE-IFS

Author: Kjetil Dohlen, Jacopo Antichi, Pietro Bruno, J. L. Beuzit, R. G. Gratton, Massimo Turatto, Dino Mesa, Salvo Scuderi, Markus Feldt, A. Pavlov, O. Moeller-Nilsson, V. De Caprio, Enrico Cascone, Enrico Giro, Pascal Puget, Silvano Desidera, David Mouillet, Riccardo Claudi, and Francois Wildi
Subjects: Physics, business.industry, Near-infrared spectroscopy, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Stars, Optics, Integral field spectrograph, Planet, Calibration, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Spectral resolution, business, Astrophysics::Galaxy Astrophysics, Data reduction
Abstract: The 2nd generation VLT instrument SPHERE will include an integral field spectrograph to enhance the capabilities of detection of planetary companions close to bright stars. SPHERE-IFS is foreseen to work in near IR (0.95-1.65 micron) at low spectral resolution. This paper describes the observing strategies, the adopted hardware solutions for calibrating the instrument, and the data reduction procedures that are mandatory for the achievement of the extreme contrast performances for which the instrument is designed.
Published: 2008
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80. Low order high accuracy deformable mirror based on electromagnetic actuators

Author: Tony Maulaz, Francois Wildi, and Gabriel Mühlebach
Subjects: Physics, business.industry, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Order (ring theory), GeneralLiterature_MISCELLANEOUS, Deformable mirror, law.invention, Power (physics), Telescope, Compact space, law, Simplicity (photography), Data_FILES, Electronic engineering, Computer vision, Artificial intelligence, business, Actuator, Adaptive optics
Abstract: Building on the technology developed to make deformable secondary mirrors for large telescopes, we show that a new breed of tip-tilt and low order deformable mirrors can be designed to satisfy the need of a large number of traditional astronomical AO systems that rely on a high order piezo deformable mirror compounded with a tip-tilt mirror to compensate for the large image motion present in the atmosphere. Using a new paradigm, we are developing a compact 50mm deformable mirror which benefits from a large computer power used to implement powerful control algorithms that allow speeding up the mirror response. Freed from the space and geometrical constraints that deformable secondary mirrors must respect, our mirror also displays elegant simplicity and compactness.
Published: 2007
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81. The SPHERE exoplanet imager: status report at PDR

Author: Rens Waters, Markus Kasper, Farrokh Vakili, Enrico Fedrigo, Anthony Boccaletti, Kjetil Dohlen, H. M. Schmid, David Mouillet, Norbert Hubin, Pierre Baudoz, Anne-Marie Lagrange, Jacopo Antichi, Raffaele Gratton, Michel Saisse, Maud Langlois, Cyril Petit, Riccardo Claudi, Claire Moutou, Marcel Carbillet, Massimo Turatto, Christian Thalmann, Patrick Rabou, Andrea Baruffolo, Jean-Luc Beuzit, Thierry Fusco, Markus Feldt, Johan Pragt, Ronald Roelfsema, Pascal Puget, Thomas Henning, A. Pavlov, Philippe Feautrier, Eric Stadler, Francois Wildi, Rainer Lenzen, Julien Charton, Stéphane Udry, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Astronomie du LESIA, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris
Subjects: Physics, medicine.medical_specialty, business.industry, Polarimetry, Astronomy, Optical polarization, Exoplanet, law.invention, Spectral imaging, Integral field spectrograph, Optics, Planet, law, medicine, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], business, Adaptive optics, Coronagraph
Abstract: The SPHERE is an exo-solar planet imager, which goal is to detect giant exo-solar planets in the vicinity of bright stars and to characterize them through spectroscopic and polarimetric observations. It is a complete system with a core made of an extreme-Adaptive Optics (AO) turbulence correction, pupil tracker and interferential coronagraphs. At its back end, an Infra-Red Dual-beam Imaging and Spectroscopy science module and an integral field spectrograph work in the Near Infrared (NIR) Y, J, H and Ks bands (0.95 - 2.32μm) and a high resolution polarization camera covers the visible (0.6 - 0.9 μm) region. We describe briefly the science goals of the instrument and deduce the top-level requirements. This paper presents the system architecture, and reviews each of the main sub-systems. The results of the latest end-to-end simulations are shown and an update of the expected performance is given. The project has been officially kicked-off in March 2006, it is presently undergoing Preliminary Design Review and is scheduled for 1st light in early 2011. This paper reviews the present design of SPHERE but focuses on the changes implemented since this project was presented the last time to this audience.
Published: 2007
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82. Performance of the VLT Planet Finder SPHERE

Author: Francois Wildi, Thomas Henning, A. Pavlov, Alice Zurlo, Andrea Baruffolo, David Mouillet, Anne Costille, Matteo Albéri, Jacopo Antichi, Enrico Giro, Silvano Desidera, Riccardo Claudi, Kjetil Dohlen, Jean-Luc Beuzit, O. Moeller-Nilsson, Anne-Lise Maire, Stéphane Udry, A. Boccaletti, Farrokh Vakili, Arthur Vigan, Bernardo Salasnich, Mickael Bonnefoy, Maud Langlois, Patrice Martinez, E. Sissa, Markus Kasper, Rens Waters, Thierry Fusco, Markus Feldt, Raffaele Gratton, Daniela Fantinel, C. Moutou, Dino Mesa, Massimo Turatto, Pascal Puget, Jean-François Sauvage, NASA Goddard Space Flight Center (GSFC), 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), 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)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), 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 Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), 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, 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), University of Geneva, Genève, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, 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), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, ESO, Physics Department [Garching], Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Centre de Recherche Astrophysique de Lyon (CRAL), 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), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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), ITA, Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), 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), 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), Environnements et Paléoenvironnements OCéaniques (EPOC), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), 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)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-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), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), ONERA, Technical University of Munich (TUM)-Technical University of Munich (TUM), and Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, 010308 nuclear & particles physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Order (ring theory), Astronomy and Astrophysics, 01 natural sciences, Exoplanet, Spectral line, law.invention, Telescope, Optics, Software, Integral field spectrograph, Space and Planetary Science, law, 0103 physical sciences, Deconvolution, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], business, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Data reduction
Abstract: We present the performance of the Integral Field Spectrograph (IFS) of SPHERE, the high-contrast imager for the ESO VLT telescope designed to perform imaging and spectroscopy of extrasolar planets, obtained from tests performed at the Institute de Plan\'etologie et d'Astrophysique de Grenoble facility during the integration phase of the instrument.} {The tests were performed using the instrument software purposely prepared for SPHERE. The output data were reduced applying the SPHERE data reduction and handling software, adding an improved spectral deconvolution procedure. To this aim, we prepared an alternative procedure for the spectral subtraction exploiting the principal components analysis algorithm. Moreover, a simulated angular differential imaging procedure was also implemented to estimate how the instrument performed once this procedure was applied at telescope. The capability of the IFS to faithfully retrieve the spectra of the detected faint companions was also considered.} {We found that the application of the updated version of the spectral deconvolution procedure alone, when the algorithm throughput is properly taken into account, gives us a $5\sigma$ limiting contrast of the order of 5$\times$$10^{-6}$ or slightly better. The further application of the angular differential imaging procedure on these data should allow us to improve the contrast by one order of magnitude down to around 7$\times$$10^{-7}$ at a separation of 0.3 arcsec. The application of a principal components analysis procedure that simultaneously uses spectral and angular data gives comparable results. Finally, we found that the reproducibility of the spectra of the detected faint companions is greatly improved when angular differential imaging is applied in addition to the spectral deconvolution., Comment: 13 pages, 23 figures
Published: 2015
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83. SPHERE: A planet finder instrument for the VLT

Author: Kjetil Dohlen, Enrico Fedrigo, Riccardo Claudi, Norbert Hubin, Gérard Rousset, Claire Moutou, Markus Kasper, Thierry Fusco, Markus Feldt, Jean-Luc Gach, Maud Langlois, Johan Pragt, Julien Charton, H. M. Schmid, Alessandro Berton, Pierre Baudoz, Massimo Turatto, Daphne Stamm, Christophe Fabron, Raffaele Gratton, Cyril Petit, Francois Wildi, Anthony Boccaletti, Philippe Feautrier, Eric Stadler, Michel Saisse, Patrick Rabou, Mark Downing, David Mouillet, Jacopo Antichi, Marcel Carbillet, Andrea Baruffolo, Jean-Luc Beuzit, Pascal Puget, Rens Waters, Andy Longmore, 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, 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: 010309 optics, Physics, Planet, 0103 physical sciences, Astronomy, 010303 astronomy & astrophysics, 01 natural sciences
Abstract: Ground-based and Airborne instrumentation for Astronomy, eds. I. S. McLean and M. Iye, SPIE Proc. 6269, p. 62690Q (2006); International audience
Published: 2006
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84. Adaptive Optics Science with the MMT Adaptive Secondary: Mid-IR AO Imaging of the Post-AGB Star AC Her

Author: John H. Bieging, Don Fisher, William F. Hoffmann, Doug Miller, Roger Angel, Phil Hinz, Guido Brusa, Michael Lloyd-Hart, Francois Wildi, Beth Biller, and Laird M. Close
Subjects: Physics, Stars, Astronomy, Asymptotic giant branch, H band, Astrophysics, Deconvolution, Adaptive optics
Abstract: The world’s first adaptive secondary has been commissioned at the 6.5m MMT. Early science results suggests that it is unique and highly productive. Nearly diffraction-limited 0.07” H band images have been obtained of the Trapezium core [Close et al. 2003b]. Moreover, an adaptive secondary makes low emissivity Mid-IR (8-20 micron) AO science possible for the first time. We have obtained the first Mid-IR AO results with Strehls of ∼100% from 8-20 microns. The very high PSF stability at such Strehls has allowed us to rule out any extended (> 0.2 ) structure around the post-AGB stars AC Her and Alpha Her [Close et al. 2003c]. In addition, Biller et al. (2003) has used this PSF stability to obtain super-resolutions through deconvolution. The resulting 0.1” images of the AGB star RV Boo detects a dust disk for the first time [Biller et al. 2003].
Published: 2005
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85. Off-line and on-line modal optimization of the MMT-AO system

Author: B. Girardet, Francois Wildi, and Guido Brusa
Subjects: Wavefront, Optics, Modal, Control theory, Computer science, business.industry, Integrator, Line (geometry), Sensitivity (control systems), Optimal control, business, Adaptive optics
Abstract: The MMT adaptive optics system has been in operation for over 2 years. Besides being a technological demonstration, it has achieved remarkable success. However, the system is presently limited by a few factors, one of which is the lack of an optimised controller. In this paper, we review the optimised modal integrator and evaluate its potential for MMT-AO. We find that it can indeed increase the system sensitivity by one magnitude but that a careful analysis of wave front sensor data must be performed to remove artefacts that can severely bias the outcome of the optimization.
Published: 2005
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86. GRAPHIC: The Geneva Reduction and Analysis Pipeline for High-contrast Imaging of planetary Companions

Author: Stéphane Udry, Damien Ségransan, Francois Wildi, and Janis Hagelberg
Subjects: Physics, Pipeline (computing), Brown dwarf, Astronomy, Astronomy and Astrophysics, Context (language use), Astrophysics, Planetary system, Rotation, Protoplanetary disk, 7. Clean energy, Radial velocity, Stars, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics
Abstract: We present a new analysis and reduction pipeline for the detection of planetary companions using Angular Differential Imaging. The pipeline uses Fourier transforms for image shifting and rotation in order to achieve very low signal loss. Furthermore it is parallelised in order to run on computer clusters of up to 1024 cores. The pipeline was developed in Geneva for the ongoing direct imaging campaign for stars with radial velocity drifts in the HARPS and CORALIE radial-velocity planet-search surveys. In addition to that, a disk mode has been implemented in the context of observations of the protoplanetary disk around HD142527.
Published: 2013
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87. Determining the interaction matrix using starlight

Author: Francois Wildi and Guido Brusa
Subjects: Wavefront, Physics, business.industry, Cassegrain reflector, Starlight, law.invention, Telescope, Matrix (mathematics), Optics, Signal-to-noise ratio, law, Secondary mirror, business, Adaptive optics
Abstract: The adaptive optics system of the 6.5m MMT, based on a deformable secondary mirror has been of the sky now for 6 runs of roughly 2 weeks each. Altogether its performance has been quite satisfactory with a crop of science results. However, even if the mirror has shown it promises, it has proven difficult to improve the system in terms of wavefront quality much beyond what it achieved during 1st light. In particular, it has not been possible to improve image quality by using a larger number of modes than the 52 modes used originally. One reason for this behavior could be that the interaction matrix used to build the AO controller has been measured in lab conditions using a different optical set-up than the one on the telescope. In a Cassegrain adaptive secondary AO system measuring the interaction matrix in the way all other AO systems do is impossible when the secondary is mounted on the telescope. In this paper, we present a way of measuring the interaction matrix on the telescope using real natural guide stars as sources. We present simulations results that show that this method can be used to measure the interaction matrix to a high signal-to-noise ratio.
Published: 2004
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88. MMT adaptive secondary: first AO closed-loop results

Author: Roberto Biasi, Daniele Gallieni, Don Fisher, Fabio Zocchi, Douglas L. Miller, Guido Brusa, Armando Riccardi, Richard G. Allen, Francois Wildi, Hubert M. Martin, and Michael Lloyd-Hart
Subjects: Wavefront, Physics, business.industry, Wavefront sensor, Frame rate, Deformable mirror, law.invention, Telescope, Optics, law, Calibration, Electronic engineering, business, Secondary mirror, Adaptive optics
Abstract: The adaptive secondary for the MMT is the first mirror of its kind. It was designed to allow the application of wavefront corrections (including tip-tilt) directly at the secondary mirror location. Among the advantages of such a choice for adaptive optics operation are higher throughput, lower emissivity, and simpler optical setup. Furthermore, this specific implementation provides capabilities that are not found in most correctors including internal position feedback, large stroke (to allow chopping) and provision for absolute position calibration. The mirror has now been used at the MMT during several runs where it has performed reliably. In this paper we discuss the mirror operation and AO performance achieved during these runs in which the adaptive secondary has been operating in conjunction with a Shack-Hartmann wavefront sensor as part of the MMT adaptive optics system. In particular we mention a residual mirror position error due to wind buffeting and other errors of ≈ 15 nm rms surface and a stable closed loop operation with a 0dB point of the error transfer function in the range 20-30 Hz limited mainly by the wavefront sensor maximum frame rate. Because of the location of the adaptive secondary with respect to the wavefront sensor camera, reimaging optics are required in order to perform the optical interaction matrix measurements needed to run the AO loop. This optical setup has been used in the lab but not replicated at the telescope so far. We will discuss the effects of the lack of such an internal calibration on the AO loop performances and a possible alternative to the lab calibration technique that uses directly light from sky objects.
Published: 2003
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89. MMT adaptive secondary: performance evaluation and field testing

Author: Armando Riccardi, Hubert M. Martin, Roberto Biasi, Michael Lloyd-Hart, Don Fisher, Francois Wildi, Doug Miller, Piero Salinari, Guido Brusa, Daniele Gallieni, Fabio Zocchi, and Richard G. Allen
Subjects: Physics, Wavefront, Interferometry, Optics, Duty cycle, business.industry, Astronomical interferometer, Wavefront sensor, business, Adaptive optics, Secondary mirror, Deformable mirror
Abstract: The adaptive secondary for the MMT (called MMT336) is the first mirror of its kind. It was designed to allow the application of wavefront corrections (including tip-tilt) directly at the secondary mirror location. Among the advantages of such a choice for adaptive optics operation are higher throughput, lower emissivity, and simpler optical setup. The mirror also has capabilities that are not found in most correctors including internal position feedback, large stroke (to allow chopping) and provision for absolute position calibration. The 336 actuator adaptive secondary for MMT has been used daily for over one year in our adaptive optics testing facility which has built confidence in the mirror operation and allowed us to interface it to the MMT adaptive optics system. Here we present the most recent data acquired in the lab on the mirror performance. By using interferometer measurements we were able to achieve a residual surface error of approximately 40nm rms. Coupling the mirror with a Shack-Hartmann wavefront sensor we obtained a stable closed loop operation with a -3dB closed loop bandwidth of approximately 30Hz limited by the wavefront sensor frame rate. We also present some preliminary results that show a 5Hz, 90% duty cycle, ±5 arcsec chopping of the mirror. Finally the experience gained and the problems encountered during the first light adaptive optics run at the telescope will be briefly summarized. A more extensive report can be found in another paper also presented at this conference.
Published: 2003
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90. Towards first light of the 6.5m MMT adaptive optics system with deformable secondary mirror

Author: Laird M. Close, Francois Wildi, Armando Riccardi, Guido Brusa, Michael Lloyd-Hart, and Hubert M. Martin
Subjects: Physics, Wavefront, business.industry, First light, Deformable mirror, law.invention, Telescope, Optics, law, Secondary mirror, business, Adaptive optics, Actuator, Digital signal processing
Abstract: In this communication, we present the progress of the 6.5m MMT adaptive optics system. During the last part of 2001 and the 1st part of 2002, the system has been validated in the laboratory statically and dynamically with sample frequencies of up to 550 Hz. In June 2002, an attempt has been made to make this system work on the telescope but has been hampered by mechanical failures. However, ease of installation of the system and open-loop operation of the mirror was demonstrated at this occasion and offers reasons to be optimistic on the future of the system. The MMT-AO system is the first AO system to compensate the aberrated wavefront at the telescope's secondary mirror. This approach has unique advantages in terms of optical simplicity, high throughput and low emissivity. Its realization presents many technical challenges, which have now been overcome. Today, the deformable mirror is characterized and accepted. It features a 1.8 mm thick 640mm diameter convex aspheric mirror (manufactured at the Steward Observatory Mirror Lab), mounted on a 50 mm thick ULE reference body with 336 actuators, as well as a cluster of 168 DSP’s and associated analog circuitry for position sensing and actuator driving. The system has been characterized in the laboratory at sampling speeds up to 550 Hz and had been integrated on the telescope.
Published: 2003
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91. Progress of the MMT adaptive optics program

Author: Doug Miller, R. G. Allen, Roberto Biasi, Francois Wildi, Armando Riccardi, Buddy Martin, Daniele Gallieni, Michael Lloyd-Hart, and Guido Brusa-Zappellini
Subjects: Physics, Wavefront, business.industry, Optical engineering, Wavefront sensor, Deformable mirror, law.invention, Telescope, Autocollimation, Optics, law, Adaptive optics, Secondary mirror, business
Abstract: The adaptive optics (AO) system for the 6.5 m MMT conversion telescope is the first to compensate the aberrated wavefront at the telescope's secondary mirror. This approach has unique advantages in terms of optical simplicity, high throughput and low emissivity. Its realization presents many technical challenges, which have now been overcome. The deformable mirror is now characterized and accepted. It features a 1.9mm thick 640mm diameter convex aspheric mirror (manufactured at the Steward Observatory Mirror Lab), mounted on a 50 mm thick ULE reference body with 336 actuators, as well as a cluster of 168 DSP's and associated analog circuitry. A wavefront sensor with integrated CCD and lenslet array has also been completed. The complete system is now starting to produce laboratory results, which we present below. Closed loop operation is tested under an auto-collimation illumination system that reflects aberrated artificial starlight from the convex secondary.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Published: 2002
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92. The Extreme Stellar-signals Project. III. Combining Solar Data from HARPS, HARPS-N, EXPRES, and NEID

Author: Lily L. Zhao, Xavier Dumusque, Eric B. Ford, Joe Llama, Annelies Mortier, Megan Bedell, Khaled Al Moulla, Chad F. Bender, Cullen H. Blake, John M. Brewer, Andrew Collier Cameron, Rosario Cosentino, Pedro Figueira, Debra A. Fischer, Adriano Ghedina, Manuel Gonzalez, Samuel Halverson, Shubham Kanodia, David W. Latham, Andrea S. J. Lin, Gaspare Lo Curto, Marcello Lodi, Sarah E. Logsdon, Christophe Lovis, Suvrath Mahadevan, Andrew Monson, Joe P. Ninan, Francesco Pepe, Rachael M. Roettenbacher, Arpita Roy, Nuno C. Santos, Christian Schwab, Guđmundur Stefánsson, Andrew E. Szymkowiak, Ryan C. Terrien, Stephane Udry, Sam A. Weiss, François Wildi, Thibault Wildi, and Jason T. Wright
Subjects: Stellar activity, Solar activity, Spectrometers, Astronomical instrumentation, Radial velocity, Exoplanet detection methods, Astronomy, QB1-991
Abstract: We present an analysis of Sun-as-a-star observations from four different high-resolution, stabilized spectrographs—HARPS, HARPS-N, EXPRES, and NEID. With simultaneous observations of the Sun from four different instruments, we are able to gain insight into the radial velocity precision and accuracy delivered by each of these instruments and isolate instrumental systematics that differ from true astrophysical signals. With solar observations, we can completely characterize the expected Doppler shift contributed by orbiting Solar System bodies and remove them. This results in a data set with measured velocity variations that purely trace flows on the solar surface. Direct comparisons of the radial velocities measured by each instrument show remarkable agreement with residual intraday scatter of only 15–30 cm s ^−1 . This shows that current ultra-stabilized instruments have broken through to a new level of measurement precision that reveals stellar variability with high fidelity and detail. We end by discussing how radial velocities from different instruments can be combined to provide powerful leverage for testing techniques to mitigate stellar signals.
Published: 2023
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93. Adaptive optics for the 6.5-m MMT

Author: Hubert M. Martin, George Z. Angeli, Stephen M. Miller, Michael Lloyd-Hart, Francois Wildi, Roger Angel, Bruce C. Fitz-Patrick, Matthew A. Kenworthy, Patrick C. McGuire, and Robert L. Johnson
Subjects: Physics, Wavefront, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Physics::Optics, Cassegrain reflector, Astrophysics::Cosmology and Extragalactic Astrophysics, law.invention, Telescope, Low emissivity, Optics, law, Adaptive system, Adaptive optics, business, Secondary mirror, Throughput (business), Astrophysics::Galaxy Astrophysics
Abstract: The adaptive optics system for the 6.5 m MMT conversion telescope will be the first to compensate the aberrated wavefront at the telescope's secondary mirror. This approach has unique advantages in terms of optical simplicity, high throughput and low emissivity. We report here the present state of construction, and the results of static and dynamic performance tests of the Cassegrain optical package.
Published: 2000
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94. Optical fabrication of the MMT adaptive secondary mirror

Author: Hubert M. Martin, Lee R. Dettmann, Stephen M. Miller, Ciro Del Vecchio, Francois Wildi, Bryan Smith, and James H. Burge
Subjects: Physics, Wavefront, Wavelength, Optics, Fabrication, business.industry, Shell (structure), Polishing, Profilometer, business, Secondary mirror, Adaptive optics
Abstract: We describe the optical fabrication of the adaptive secondary mirror for the MMT. The 640 mm f/15 secondary consists of a flexible glass shell, 1.8 mm thick, whose shape is controlled by 336 electromagnetic actuators. It is designed to give diffraction-limited images at a wavelength of 1 micron. For generating and polishing, the shell was supported by attaching it to a rigid glass blocking body with a thin layer of pitch. It could then be figured and measured using techniques developed for rigid secondaries. The highly aspheric surface was polished with a 30 cm stressed lap and small passive tools, and measured using a swing-arm profilometer and a holographic test plate. The goal for fabrication was to produce diffraction-limited images in the visible, after simulated adaptive correction using only a small fraction of the typical actuator forces. This translates into a surface accuracy of less than 19 nm rms with correction forces of less than 0.05 N rms. We achieved a surface accuracy of 8 nm rms after simulated correction with forces of 0.02 N rms.
Published: 2000
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95. Full-system laboratory testing of the F/15 deformable secondary mirror for the new MMT adaptive optics system

Author: Roberto Biasi, James H. Burge, George Z. Angeli, Chunyu Zhao, Stephen M. Miller, Francois Wildi, Roland J. Sarlot, Daniele Gallieni, Robert L. Johnson, James Roger P. Angel, Claudio Franchini, Ciro Del Vecchio, Guido Brusa-Zappellini, Richard M. Cordova, Skip Schaller, Michael Lloyd-Hart, Bruce C. Fitz-Patrick, Warren B. Davison, Todd K. Barrett, David G. Sandler, Brian L. Stamper, Mario Andrighettoni, John M. Hughes, Piero Salinari, Patrick C. McGuire, Mario Rascon, Armando Riccardi, M. Rademacher, Matthew A. Kenworthy, and Cynthia J. Bresloff
Subjects: Physics, Wavefront, Spherical aberration, Optics, Cardinal point, business.industry, Optical engineering, Cassegrain reflector, Wavefront sensor, Secondary mirror, business, Adaptive optics
Abstract: We will present a system to perform closed-loop optical tests of the 64 cm diameter, 336 actuator adaptive secondary made at the Steward Observatory Mirror Laboratory. Testing will include Shack-Hartmann wavefront sensing and modal correction of static and dynamic aberrated wavefronts. The test optical system is designed so that experiments can be made with both the focal plane instrument and secondary installed in their normal configuration at the MMT, or with the same 9 m spacing in a laboratory test tower. The convex secondary will be illuminated at normal incidence through two 70 cm diameter lenses mounted just below. The artificial, aberrated star is projected from near the wavefront sensor in the Cassegrain focus assembly. Computer generated holograms correct for spherical aberration in the really optics at the test wavelengths of 0.594 and 1.5 micrometers . Atmospheric turbulence is reproduced by two spinning transmission plates imprinted with Kolmogorov turbulence. The Shimmulator will give us the opportunity to test fully the adaptive optics system before installation at the new MMT, hence saving much precious telescope time.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Published: 1999
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96. Construction and testing of the wavefront sensor camera for the new MMT adaptive optics system

Author: James Roger P. Angel, Troy A. Rhoadarmer, Jeff G. Capara, M. Rademacher, Matthew A. Kenworthy, Skip Schaller, John M. Hughes, Michael Lloyd-Hart, Michael Lesser, David Ouellette, J. C. Shelton, Patrick C. McGuire, Francois Wildi, Bruce C. Fitz-Patrick, and George Z. Angeli
Subjects: Wavefront, Physics, Optics, Pixel, business.industry, Detector, Guide star, Wavefront sensor, Lenslet, Frame rate, business, Adaptive optics
Abstract: This paper describes the construction and testing of the Shack-Hartmann wavefront sensor camera for the new MMT adaptive optics system. Construction and use of the sensor is greatly simplified by having the 12 X 12 lenslet array permanently glued to the detector array, obviating the need for any further realignment. The detector is a frame transfer CCD made by EEV with 80 by 80 pixels, each 24 microns square, and 4 output amplifiers operated simultaneously. 3 by 3 pixel binning is used to create in effect an array of quad-cells, each centered on a spot formed by a lenslet. Centration of the lenslet images is measured to have an accuracy of 1 micrometers rms. The maximum frame rate in the binned mode is 625 Hz, when the rms noise is 4.5-5 electrons. In use at the telescope, the guide star entering the wavefront sensor passes through a 2.4 arcsec squares field stop matched to the quall-cell size, and each lenslet samples a 54 cm square segment of the atmospherically aberrated wavefront to form a guide star image at a plate scale of 60 micrometers /arcsec. Charge diffusion between adjacent detector pixels is small: the signal modulation in 0.7 arcsec seeing is reduced by only 10 percent compared to an ideal quad-cell with perfectly sharp boundaries.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Published: 1999
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97. Astrophysical false positives in direct imaging for exoplanets: a white dwarf close to a rejuvenated star

Author: Massimo Turatto, Raffaele Gratton, Janis Hagelberg, S. Messina, Arthur Vigan, Joseph C. Carson, Valentina D'Orazi, Damien Ségransan, J. M. Almenara, Alice Zurlo, Silvano Desidera, Mickael Bonnefoy, Katia Biazzo, Francois Wildi, Stéphane Udry, Gael Chauvin, Philippe Delorme, Elvira Covino, Dino Mesa, Claire Moutou, 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), 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: Earth and Planetary Astrophysics (astro-ph.EP), Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, FOS: Physical sciences, White dwarf, Astronomy and Astrophysics, Astrophysics, Star (graph theory), Rotation, 01 natural sciences, Exoplanet, Radial velocity, Orbit, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Spectral energy distribution, Spectroscopy, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract: As is the case for all techniques involved in the research for exoplanets, direct imaging has to take into account the probability of so-called astrophysical false positives, which are phenomena that mimic the signature of objects we are seeking. In this work we aim to present a case of a false positive found during a direct imaging survey conducted with VLT/NACO. A promising exoplanet candidate was detected around the K2-type star HD\,8049 in July 2010.Its contrast of $\Delta H$=7.05 at 1.57 arcsec allowed us to guess the presence of a 35 \MJup companion at 50 projected AU, for the nominal system age and heliocentric distance.To check whether it was gravitationally bound to the host star, as opposed to an unrelated background object, we re-observed the system one year later and concluded a high probability of a bound system. We also used radial velocity measurements of the host star, spanning a time range of $\sim$ 30 yr, to constrain the companion's mass and orbital properties, as well as to probe the host star's spectral age indicators and general spectral energy distribution. We also obtained for the companion $U$-band imaging with EFOSC and $NIR$ spectroscopy. Combining all these information we conclude that the companion of HD\,8049 is a white dwarf (WD), with temperature $T_{eff}=18800 \pm 2100$ K and mass $M_{WD}=0.56 \pm 0.08 M_{\odot}$. The significant radial velocity trend coupled with the imaging data indicate that the most probable orbit has a semimajor axis of about 50 AU.The discrepancy between the age indicators suggested against a bona-fide young star. The moderately large level of chromospheric activity and fast rotation, mimicking the properties of a young star, might be induced by the exchange of mass with the progenitor of the WD. This example demonstrates some of the challenges in determining accurate age estimates and identifications of faint companions., Comment: 12 pages, 10 figures, 4 tables. Accepted for publication in Astronomy&Astrophysics
Published: 2013
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98. Sphere-zimpol system testing: Status report on polarimetric high contrast results

Author: Kjetil Dohlen, Johan Pragt, Jean-Louis Lizon, Carsten Dominik, Norbert Hubin, Markus Kasper, Andrea Baruffolo, Jean-François Sauvage, Mark Downing, Jean-Luc Beuzit, D. Gisler, Hans Martin Schmid, David Mouillet, A. Pavlov, Francois Wildi, Matthew A. Kenworthy, Anne Costille, Patrice Martinez, Anthonoy Boccaletti, Pascal Puget, Christoph U. Keller, Ronald Roelfsema, Eddy Elswijk, Bernardo Salasnich, Andreas Bazzon, Christian Thalmann, Menno de Haan, and Shaklan, S.
Subjects: Physics, business.industry, Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, media_common.quotation_subject, Astronomy, Polarimetry, System testing, Polarimeter, Exoplanet, law.invention, Optics, law, Planet, Contrast (vision), Proceedings of SPIE, business, Adaptive optics, Coronagraph, media_common
Abstract: SPHERE (Spectro-Polarimetric High Contrast Exoplanet Research) is one of the first instruments which aim for the direct detection from extra-solar planets. SPHERE commissioning is foreseen in 2013 on the VLT. ZIMPOL (Zurich Imaging Polarimeter) is the high contrast imaging polarimeter subsystem of the ESO SPHERE instrument. ZIMPOL is dedicated to detect the very faint reflected and hence polarized visible light (600-900 nm) from extrasolar planets. It is located behind an extreme AO system (SAXO) and a stellar coronagraph. We present the first high contrast polarimetric results obtained for the fully integrated SPHERE-ZIMPOL system. We have measured the polarimetric high contrast performance of several coronagraphs: a Classical Lyot on substrate, a suspended Classical Lyot and two 4 Quadrant Phase Mask coronagraphs. We describe the impact of crucial system parameters – Adaptive Optics, Coronagraphy and Polarimetry - on the contrast performance.
Published: 2013

99. Lessons learned from the first adaptive secondary mirror

Author: Don Fisher, Guido Brusa, Michael Lloyd-Hart, Douglas L. Miller, Armando Riccardi, and Francois Wildi
Subjects: Physics, Class (computer programming), business.industry, Large Binocular Telescope, Context (language use), law.invention, Telescope, Software, law, Retrofitting, business, Secondary mirror, Adaptive optics, Computer hardware, Simulation
Abstract: The adaptive optics system for the 6.5 m MMT, based on a deformable secondary mirror, has been on the sky now for three commissioning runs totalling approximately 30 nights. The mirror has begun to demonstrate uniquely clean point-spread functions, high photon efficiency, and very low background in the thermal infrared. In this paper we review the lessons learned from the first few months of operation. Broadly, the hardware works well, and we are learning how procedures related to operation, system error recovery, and safety should be implemented in software. Experience with the MMT system is now guiding the design of the second and third adaptive secondaries, being built for the Large Binocular Telescope. In this context, we discuss the general requirements for retrofitting an adaptive secondary to an existing large telescope. Finally, we describe how the new technology can support the design of adaptive optics for 30-cm class telescopes, with particular attention to ground-layer adaptive optics (GLAO), where conjugation as close as possible to the turbulence is important.

100. Dynamical models to explain observations with SPHERE in planetary systems with double debris belts

Author: N. Pawellek, R. Ligi, Raphaël Galicher, C. Lazzoni, Luigi Lessio, T. Kopytova, Michael Meyer, Francois Wildi, M. Feldt, Anne-Marie Lagrange, Daniela Fantinel, Ch. Ginski, Anthony Cheetham, Bernardo Salasnich, T. Schmidt, Maud Langlois, V. De Caprio, Wolfgang Brandner, S. Incorvaia, Graeme Salter, G. Farisato, Mickael Bonnefoy, M. Cudel, Salvo Scuderi, Francesco Marzari, Alice Zurlo, J. L. Beuzit, E. Sissa, Markus Janson, Pietro Bruno, Andreas Bazzon, Philippe Delorme, Dino Mesa, Anne-Lise Maire, M. Samland, C. Perrot, Stéphane Udry, R. G. Gratton, F. Cantalloube, Riccardo Claudi, Daniel Rouan, Sebastian Daemgen, Henning Avenhaus, Beth Biller, Jacopo Antichi, S. Peretti, Enrico Cascone, E. Sezestre, Johan Olofsson, Th. Henning, H. LeCoroller, J. Milli, Enrico Giro, Jean-Loup Baudino, Massimo Turatto, Andrea Baruffolo, Julien Girard, M. Kasper, Esther Buenzli, Janis Hagelberg, Gael Chauvin, Quentin Kral, David Mouillet, Arthur Vigan, Mariangela Bonavita, Francois Menard, Anthony Boccaletti, Silvano Desidera, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'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), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, INAF - Osservatorio Astronomico di Capodimonte (OAC), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Institute of Astronomy [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), 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), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Stockholm University, European Southern Observatory (ESO), Geneva Observatory, University of Geneva [Switzerland], 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), 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 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]), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Université de Genève = University of Geneva (UNIGE), Universiteit Leiden, ANR-16-CE31-0013,PLANET-FORMING-DISKS,De meilleurs modèles pour de meilleures données(2016), Pawellek, Nicole [0000-0002-9385-9820], and Apollo - University of Cambridge Repository
Subjects: GENERAL [KUIPER BELT], IMAGE PROCESSING, GENERALS [KUIPER BELT], FOS: Physical sciences, DEBRIS, Orbital eccentricity, techniques: image processing, Astrophysics, IMAGE PROCESSING [TECHNIQUES], 01 natural sciences, methods: analytical, Planet, instrumentation: high angular resolution, 0103 physical sciences, ANALYTICAL [METHODS], Circular orbit, 010303 astronomy & astrophysics, Physics, Earth and Planetary Astrophysics (astro-ph.EP), PLANET-DISK INTERACTIONS, Debris disk, planet-disk interactions, 010308 nuclear & particles physics, Astronomy and Astrophysics, Mass ratio, Planetary system, Exoplanet, SPHERES, 13. Climate action, Space and Planetary Science, OBSERVATIONAL [METHODS], HIGH ANGULAR RESOLUTION [INSTRUMENTATION], Kuiper belt: general, Astrophysics::Earth and Planetary Astrophysics, ORBITS, methods: observational, Low Mass, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics, PLANETS
Abstract: A large number of systems harboring a debris disk show evidence for a double belt architecture. One hypothesis for explaining the gap between the belts is the presence of one or more planets dynamically carving it. This work aims to investigate this scenario in systems harboring two components debris disks. All the targets in the sample were observed with the SPHERE instrument which performs high-contrast direct imaging. Positions of the inner and outer belts were estimated by SED fitting of the infrared excesses or, when available, from resolved images of the disk. Very few planets have been observed so far in debris disks gaps and we intended to test if such non-detections depend on the observational limits of the present instruments. This aim is achieved by deriving theoretical predictions of masses, eccentricities and semi-major axes of planets able to open the observed gaps and comparing such parameters with detection limits obtained with SPHERE. The relation between the gap and the planet is due to the chaotic zone around the orbit of the planet. The radial extent of this zone depends on the mass ratio between the planet and the star, on the semi-major axis and on the eccentricity of the planet and it can be estimated analytically. We apply the formalism to the case of one planet on a circular or eccentric orbit. We then consider multi-planetary systems: 2 and 3 equal-mass planets on circular orbits and 2 equal-mass planets on eccentric orbits in a packed configuration. We then compare each couple of values (M,a), derived from the dynamical analysis of single and multiple planetary models, with the detection limits obtained with SPHERE. Our results show that the apparent lack of planets in gaps between double belts could be explained by the presence of a system of two or more planets possibly of low mass and on an eccentric orbits whose sizes are below the present detection limits., Comment: 23 pages, 13 figures
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