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19 results on '"Steward Observatory (STEWARD OBSERVATORY)"'

1. Hubble Frontier Fields: predictions for the return of SN Refsdal with the MUSE and GMOS spectrographs

Author: Jean-Paul Kneib, Hakim Atek, Richard Massey, Eric Jullo, Guillaume Mahler, Johan Richard, Eiichi Egami, Kenda Knowles, B. Clement, Harald Ebeling, Mathilde Jauzac, Graham P. Smith, Dominique Eckert, Marceau Limousin, Priyamvada Natarajan, M. Rexroth, Institute for Computational Cosmology (ICC), Durham University, 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), 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), AUTRES, School of Physics and Astronomy [Birmingham], University of Birmingham [Birmingham], Ecole Polytechnique Fédérale de Lausanne (EPFL), Yale University [New Haven], Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), and 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)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Strong gravitational lensing, Dark matter, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, strong [Gravitational lensing], 01 natural sciences, 0103 physical sciences, Cluster (physics), clusters: individual: MACS J1149. [Galaxies], 010306 general physics, galaxies: clusters: individual: MACS J1149, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Very Large Telescope, gravitational lensing: strong, Astronomy, Astronomy and Astrophysics, Multi Unit Spectroscopic Explorer, Astrophysics - Astrophysics of Galaxies, Galaxy, Supernova, Abell 2744, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), supernovae: individual: SN Refsdal, Astrophysics - Cosmology and Nongalactic Astrophysics, individual: SN Refsdal [Supernovae]
Abstract: We present a high-precision mass model of the galaxy cluster MACSJ1149.6+2223, based on a strong-gravitational-lensing analysis of Hubble Space Telescope Frontier Fields (HFF) imaging data and spectroscopic follow-up with Gemini/GMOS and VLT/MUSE. Our model includes 12 new multiply imaged galaxies, bringing the total to 22, comprised of 65 individual lensed images. Unlike the first two HFF clusters, Abell 2744 and MACSJ0416.1-2403, MACSJ1149 does not reveal as many multiple images in the HFF data. Using the Lenstool software package and the new sets of multiple images, we model the cluster with several cluster-scale dark-matter halos and additional galaxy-scale halos for the cluster members. Consistent with previous analyses, we find the system to be complex, composed of five cluster-scale halos. Their spatial distribution and lower mass, however, makes MACSJ1149 a less powerful lens. Our best-fit model predicts image positions with an RMS of 0.91". We measure the total projected mass inside a 200~kpc aperture as ($1.840\pm 0.006$)$\times 10^{14}$M$_{\odot}$, thus reaching again 1% precision, following our previous HFF analyses of MACSJ0416.1-2403 and Abell 2744. In light of the discovery of the first resolved quadruply lensed supernova, SN Refsdal, in one of the multiply imaged galaxies identified in MACSJ1149, we use our revised mass model to investigate the time delays and predict the rise of the next image between November 2015 and January 2016., Comment: Submitted to MNRAS -- 14 pages, 8 figures, 6 tables
Published: 2016
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2. Mechanism and kinetics of electrocarboxylation of aromatic ketones in ionic liquid

Author: Klaudia Wagner, Andrew Doherty, Valentin Puchelle, Eunan Marley, Rachid Barhdadi, Gordon G. Wallace, laboratoire Eau Environnement et Systèmes Urbains (LEESU), AgroParisTech-École des Ponts ParisTech (ENPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Steward Observatory (STEWARD OBSERVATORY), and University of Arizona
Subjects: 010405 organic chemistry, General Chemical Engineering, Kinetics, electrocarboxylations, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Chemical reaction, Coupling reaction, 0104 chemical sciences, Analytical Chemistry, chemistry.chemical_compound, Reaction rate constant, Carboxylation, chemistry, Nucleophile, IONIC LIQUIDS, Ionic liquid, [SDE]Environmental Sciences, Electrochemistry, Dimethylformamide, mechanism kinetics, ComputingMilieux_MISCELLANEOUS
Abstract: The electrochemical carboxylation of a range of substituted benzophenones was studied in 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid (IL, ([Bmpy][NTf2])). As expected, the aromatic carbonyls exhibited electrochemical reversibility for the first reduction to the radical anion at potentials which were a function of the sum of their Hammett substituent constants (Σσ). However, in the presence of CO2, the electrochemical reversibility was lost and positive shifts in reduction potentials were observed which were indicative of post-electron transfer chemical reaction which has been attributable to the nucleophilic radical anion/CO2 coupling reaction.Analysis of the positive potential shift a function of sweep rate (ν) indicated that the mechanism is either ECE or DISP1, or mixed ECE/DISP1. Also from the potential shift with ν, an apparent rate constant (kapp), and a pseudo-first order rate constant (k1), for the coupling reaction was determined and compared to molecular solvent where the rate is over two orders of magnitude lower in IL compared to dimethylformamide (DMF). The low polarity of the IL compared to DMF appears to be the cause of slow kinetics. Finally, plots of kapp vs. Σσ were strictly linear indicating that IL does not preferentially interact with any of the electrogenerated radical anions thus implying that the electrocarboxylation reaction may be a useful probe of IL environments and structure on radical anion reactions.
Published: 2017
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3. Shadows and spirals in the protoplanetary disk HD 100453

Author: C. Fontanive, Alice Zurlo, Christian Ginski, Thomas Henning, Paola Pinilla, Tomas Stolker, M. Llored, Maud Langlois, D. Gisler, O. Moeller-Nilsson, R. van Boekel, J. Pragt, Yves Magnard, Kevin Wagner, François Ménard, Jean-François Sauvage, Silvano Desidera, Antonio Garufi, David Mouillet, Geoffroy Lesur, Francois Wildi, M. Bonnefoy, Myriam Benisty, T. Buey, Raffaele Gratton, Arthur Vigan, Gael Chauvin, Anthony Boccaletti, Michiel Min, A-M. Lagrange, Jacopo Antichi, Thierry Fusco, Markus Feldt, Christophe Pinte, H. LeCoroller, Carsten Dominik, Jean-Luc Beuzit, M. Cudel, E. Sissa, Dino Mesa, J. de Boer, Attila Juhasz, Ronald Roelfsema, Cornelis P. Dullemond, M. Kasper, Stefano Facchini, Adriana Pohl, Daniel Apai, Sascha P. Quanz, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Astronomical Institute Anton Pannekoek, University of Amsterdam, Max-Planck-Institut für Astronomie (MPIA), Leiden Observatory, Institute of Earth Sciences, Heidelberg University, 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), 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), SRON Netherlands Institute for Space Research, Department of Astronomy, Steward Observatory, Institute of Astronomy, Madingley Road, Cambridge CB3, OHA, UK, Max-Planck-Institut fur extraterrestrische Physik, Universidad Autononoma de Madrid, Dpto. Fisica Teorica, Facultad de Ciencias, Campus de Cantoblanco, 28049, Madrid, Spain, Institute for Astronomy, Department of Physics, ETH Zürich, Nucleo de Astronomia, Facultad de Ingenieria, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), INAF-Osservatorio Astronomico di Padova, Institute for Astronomy, Blackford Hill, European Southern Observatory (ESO), INAF-Osservatorio Astrofisico di Arcetri (INAF-OAA), ONERA, Geneva Observatory, 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]), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Max-Planck-Gesellschaft, Leiden Observatory [Leiden], Universiteit Leiden, Institute for Theoretical Astrophysics [Heidelberg], Heidelberg University, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), SRON Netherlands Institute for Space Research (SRON), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Max-Planck-Institut für Extraterrestrische Physik (MPE), Universidad Autonónoma de Madrid, 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), Universidad Diego Portales [Santiago] (UDP), Universidade do Chile, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, ESO, Physics Department [Garching], Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), Kiepenheuer-Institut für Sonnenphysik (KIS), Université de Genève = University of Geneva (UNIGE), Universiteit Leiden [Leiden], Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), University of Geneva [Switzerland], 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), 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), 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), Technical University of Munich (TUM)-Technical University of Munich (TUM), Low Energy Astrophysics (API, FNWI), 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 Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: Brightness, FOS: Physical sciences, Astrophysics, RADIATIVE TRANSFER, Astrophysics::Cosmology and Extragalactic Astrophysics, Protoplanetary disk, OPTIQUE ADAPTATIVE, 01 natural sciences, VLT, POLARIMETRIE, POLARIMETRIC, Planet, SPHERE, 0103 physical sciences, TECHNIQUES, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Inclined orbit, Spiral galaxy, 010308 nuclear & particles physics, Scattering, protoplanetary disks, Astronomy and Astrophysics, Scale height, TRANSFERT RADIATIF, Wavelength, techniques: polarimetric, Space and Planetary Science, [SDU]Sciences of the Universe [physics], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Astrophysics - Earth and Planetary Astrophysics
Abstract: Understanding the diversity of planets requires to study the morphology and the physical conditions in the protoplanetary disks in which they form. We observed and spatially resolved the disk around the ~10 Myr old protoplanetary disk HD 100453 in polarized scattered light with SPHERE/VLT at optical and near-infrared wavelengths, reaching an angular resolution of ~0.02", and an inner working angle of ~0.09". We detect polarized scattered light up to ~0.42" (~48 au) and detect a cavity, a rim with azimuthal brightness variations at an inclination of 38 degrees, two shadows and two symmetric spiral arms. The spiral arms originate near the location of the shadows, close to the semi major axis. We detect a faint spiral-like feature in the SW that can be interpreted as the scattering surface of the bottom side of the disk, if the disk is tidally truncated by the M-dwarf companion currently seen at a projected distance of ~119 au. We construct a radiative transfer model that accounts for the main characteristics of the features with an inner and outer disk misaligned by ~72 degrees. The azimuthal brightness variations along the rim are well reproduced with the scattering phase function of the model. While spirals can be triggered by the tidal interaction with the companion, the close proximity of the spirals to the shadows suggests that the shadows could also play a role. The change in stellar illumination along the rim, induces an azimuthal variation of the scale height that can contribute to the brightness variations. Dark regions in polarized images of transition disks are now detected in a handful of disks and often interpreted as shadows due to a misaligned inner disk. The origin of such a misalignment in HD 100453, and of the spirals, is unclear, and might be due to a yet-undetected massive companion inside the cavity, and on an inclined orbit., Comment: A&A, accepted
Published: 2017
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4. First light of the VLT planet finder SPHERE. III. New spectrophotometry and astrometry of the HR 8799 exoplanetary system

Author: Zurlo, A., Vigan, Arthur, Galicher, R., Maire, A.L., Mesa, D., Gratton, R., Chauvin, G., Kasper, M., Moutou, C., Bonnefoy, M., Desidera, S., Abe, L., Apai, D., Baruffolo, A., Baudoz, P., Baudrand, J., Beuzit, J.L., Blancard, P., Boccaletti, A., Cantalloube, F., Carle, M., Cascone, E., Charton, P., Claudi, R.U., Costille, A., De Caprio, V., Dohlen, K., Dominik, C., Fantinel, D., Feautrier, P., Feldt, M., Fusco, T., Gigan, P., Girard, J.H., Gisler, D., Gluck, L., Gry, C., Henning, T., Hugot, E., Janson, M., Jaquet, M., Lagrange, A.M., Langlois, M., Llored, M., Madec, F., Magnard, Y., Martinez, P., Maurel, D., Mawet, D., Meyer, M.R., Milli, J., Moeller-Nilsson, O., Mouillet, D., Origné, A., Pavlov, A., Petit, C., Puget, P., Quanz, S.P., Rabou, P., Ramos, J., Rousset, G., Roux, A., Salasnich, B., Salter, G., Sauvage, J.F., Schmid, H.M., Soenke, C., Stadler, E., Suarez, M., Turatto, M., Udry, S., F., Vakili, Wahhaj, Z., Wildi, F., Antichi, J., Universidad Diego Portales [Santiago] (UDP), Departamento de Astronomía, Universidad de Chile = University of Chile [Santiago] (UCHILE), 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), European Southern Observatory, European Southern Observatory (ESO), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), ESO, Physics Department [Garching], Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Lunar and Planetary Laboratory [Tucson] (LPL), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), Anton Pannekoek Institute for Astronomy, University of Amsterdam [Amsterdam] (UvA), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Kiepenheuer-Institut für Sonnenphysik (KIS), AlbaNova University Center (ALBANOVA), Stockholm University, 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), California Institute of Technology (CALTECH), 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), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Universidad de Chile, 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), 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), 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), Technical University of Munich (TUM)-Technical University of Munich (TUM), 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), ONERA, Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), 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 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), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Genève = University of Geneva (UNIGE)
Subjects: TRAITEMENT IMAGE, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, SPECTROSCOPIE, ANALYSE DONNEES, ASTROMETRIE, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, HAUTE RESOLUTION, EXOPLANETE
Abstract: International audience; Context. The planetary system discovered around the young A-type HR 8799 provides a unique laboratory to: a) test planet formation theories; b) probe the diversity of system architectures at these separations, and c) perform comparative (exo)planetology.Aims. We present and exploit new near-infrared images and integral-field spectra of the four gas giants surrounding HR 8799 obtained with SPHERE, the new planet finder instrument at the Very Large Telescope, during the commissioning and science verification phase of the instrument (July–December 2014). With these new data, we contribute to completing the spectral energy distribution (SED) of these bodies in the 1.0–2.5 μm range. We also provide new astrometric data, in particular for planet e, to further constrain the orbits.Methods. We used the infrared dual-band imager and spectrograph (IRDIS) subsystem to obtain pupil-stabilized, dual-band H2H3 (1.593 μm, 1.667 μm), K1K2 (2.110 μm, 2.251 μm), and broadband J (1.245 μm) images of the four planets. IRDIS was operated in parallel with the integral field spectrograph (IFS) of SPHERE to collect low-resolution (R ~ 30), near-infrared (0.94–1.64 μm) spectra of the two innermost planets HR 8799 d and e. The data were reduced with dedicated algorithms, such as the Karhunen-Loève image projection (KLIP), to reveal the planets. We used the so-called negative planets injection technique to extract their photometry, spectra, and measure their positions. We illustrate the astrometric performance of SPHERE through sample orbital fits compatible with SPHERE and literature data.Results. We demonstrated the ability of SPHERE to detect and characterize planets in this kind of systems, providing spectra and photometry of its components. The spectra improve upon the signal-to-noise ratio of previously obtained data and increase the spectral coverage down to the Y band. In addition, we provide the first detection of planet e in the J band. Astrometric positions for planets HR 8799 bcde are reported for the epochs of July, August, and December 2014. We measured the photometric values in J, H2H3, K1K2 bands for the four planets with a mean accuracy of 0.13 mag. We found upper limit constraints on the mass of a possible planet f of 3–7 MJup . Our new measurements are more consistent with the two inner planets d and e being in a 2d:1e or 3d:2e resonance. The spectra of HR 8799 d and e are well matched by those of L6-8 field dwarfs. However, the SEDs of these objects are redder than field L dwarfs longward of 1.6 μm.
Published: 2016
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5. SN 1994W: an interacting supernova or two interacting shells?

Author: Stéphane Basa, D. John Hillier, Suvi Gezari, Luc Dessart, Thomas Matheson, Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Department of Physics and Astronomy [Pittsburgh], University of Pittsburgh (PITT), Pennsylvania Commonwealth System of Higher Education (PCSHE)-Pennsylvania Commonwealth System of Higher Education (PCSHE), 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), and Beaussier, Catherine
Subjects: Physics, Photosphere, 010308 nuclear & particles physics, Scattering, Astrophysics (astro-ph), Incoherent scatter, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Radius, 01 natural sciences, 7. Clean energy, Redshift, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Supernova, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 13. Climate action, Space and Planetary Science, 0103 physical sciences, Ejecta, 010303 astronomy & astrophysics, Line (formation)
Abstract: We present a multi-epoch quantitative spectroscopic analysis of the Type IIn SN 1994W, an event interpreted by Chugai et al. as stemming from the interaction between the ejecta of a SN and a 0.4Msun circumstellar shell ejected 1.5yr before core collapse. During the brightening phase, our models suggest that the source of optical radiation is not unique, perhaps associated with an inner optically-thick Cold Dense Shell (CDS) and outer optically-thin shocked material. During the fading phase, our models support a single source of radiation, an hydrogen-rich optically-thick layer with a near-constant temperature of ~7000K that recedes from a radius of 4.3x10^15 at peak to 2.3x10^15cm 40 days later. We reproduce the hybrid narrow-core broad-wing line profile shapes of SN 1994W at all times, invoking an optically-thick photosphere exclusively (i.e., without any external optically-thick shell). In SN 1994W, slow expansion makes scattering with thermal electrons a key escape mechanism for photons trapped in optically-thick line cores, and allows the resulting broad incoherent electron-scattering wings to be seen around narrow line cores. In SNe with larger expansion velocities, the thermal broadening due to incoherent scattering is masked by the broad profile and the dominant frequency redshift occasioned by bulk motions. Given the absence of broad lines at all times and the very low 56Ni yields, we speculate whether SN 1994W could have resulted from an interaction between two ejected shells without core collapse. The high conversion efficiency of kinetic to thermal energy may not require a SN-like energy budget for SN1994W., Comment: 36 pages (includes online tables), 16 figures, paper accepted to MNRAS, discussion section expanded, title re-worded
Published: 2009
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6. ARE ULTRA-FAINT GALAXIES AT z = 6–8 RESPONSIBLE FOR COSMIC REIONIZATION? COMBINED CONSTRAINTS FROM THE HUBBLE FRONTIER FIELDS CLUSTERS AND PARALLELS

Author: Hakim Atek, Benjamin Clément, Jean-Paul Kneib, Daniel Schaerer, Priyamvada Natarajan, Eiichi Egami, Eric Jullo, Marceau Limousin, Johan Richard, Mathilde Jauzac, Harald Ebeling, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Yale University [New Haven], Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute for Computational Cosmology (ICC), Durham University, 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), Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Université de Genève (UNIGE), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Absolute magnitude, Cosmology and Nongalactic Astrophysics (astro-ph.CO), first stars, strong. [Gravitational lensing], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, gravitational lensing:strong, 01 natural sciences, galaxies:high-redshift, Luminosity, high-redshift [Galaxies], [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], galaxies: high-redshift, 0103 physical sciences, dark ages, 010303 astronomy & astrophysics, Reionization, Astrophysics::Galaxy Astrophysics, Luminosity function (astronomy), Physics, 010308 nuclear & particles physics, James Webb Space Telescope, gravitational lensing: strong, Astronomy, Astronomy and Astrophysics, luminosity function [Galaxies], Astrophysics - Astrophysics of Galaxies, Redshift, Galaxy, galaxies: luminosity function, Space and Planetary Science, mass function, Dark ages, Astrophysics of Galaxies (astro-ph.GA), Magnitude (astronomy), reionization, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We use deep Hubble Space Telescope imaging of the Frontier Fields to accurately measure the galaxy rest-frame ultraviolet luminosity function (UV LF) in the redshift range $z \sim 6-8$. We combine observations in three lensing clusters A2744, MACS0416, MACS0717 and their associated parallels fields to select high-redshift dropout candidates. We use the latest lensing models to estimate the flux magnification and the effective survey volume in combination with completeness simulations performed in the source plane. We report the detection of 227 galaxy candidates at $z=6-7$ and 25 candidates at $z \sim 8$. While the total survey area is about 4 arcmin$^{2}$ in each parallel field, it drops to about 0.6 to 1 arcmin$^{2}$ in the cluster core fields because of the strong lensing. We compute the UV luminosity function at $z \sim 7$ using the combined galaxy sample and perform Monte Carlo simulations to determine the best fit Schechter parameters. We are able to reliably constrain the LF down to an absolute magnitude of $M_{UV}=-15.25$, which corresponds to 0.005$L^{\star}$. More importantly, we find that the faint-end slope remains steep down to this magnitude limit with $\alpha=-2.04_{-0.17}^{+0.13}$. Our results confirm the most recent results in deep blank fields but extend the LF measurements more than two magnitudes deeper. The UV LF at $z \sim 8$ is not very well constrained below $M_{UV}=-18$ due to the small number statistics and incompleteness uncertainties. To assess the contribution of galaxies to cosmic reionization we derive the UV luminosity density at $z\sim7$ by integrating the UV LF down to an observationally constrained limit of $M_{UV} = -15$. We show that our determination of Log($\rho_{UV}$)=$26.2\pm0.13$ (erg s$^{-1}$ Hz$^{-1}$ Mpc$^{-3}$) can be sufficient to maintain the IGM ionized., Comment: 13 pages, 10 figures, 4 tables, accepted for publication in ApJ
Published: 2015
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7. Hubble Frontier Fields: a high-precision strong-lensing analysis of the massive galaxy cluster Abell 2744 using similar to 180 multiple images

Author: B. Clement, M. Rexroth, Jean-Paul Kneib, Mathilde Jauzac, Eiichi Egami, Johan Richard, S. Rodney, Eric Jullo, Marceau Limousin, H. Atek, Dominique Eckert, Richard Massey, Harald Ebeling, Priyamvada Natarajan, 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), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Dark Cosmology Centre (DARK), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), Department of Astronomy, Yale University [New Haven], AUTRES, Institut Bisontin en Sciences Fondamentales (IBSF), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Université de Genève = University of Geneva (UNIGE), INAF-IASF Milano, Istituto Nazionale di Astrofisica (INAF), Steward Observatory, University of Arizona, Institute for Computational Cosmology (ICC), Durham University, Aix Marseille Université (AMU), Département de Mathématiques - EPFL, Johns Hopkins University (JHU), Observatoire Astronomique de l'Université de Genève (ObsGE), Steward Observatory (STEWARD OBSERVATORY), 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), University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), University of Geneva [Switzerland], and Université de Genève (UNIGE)
Subjects: observations. [Cosmology], Cosmology and Nongalactic Astrophysics (astro-ph.CO), [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Dark matter, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, strong [Gravitational lensing], gravitational lensing:strong, cosmology:observations, Abell 520, Brightest cluster galaxy, Weak gravitational lensing, Galaxy cluster, Astrophysics::Galaxy Astrophysics, Physics, galaxies: clusters: individual: Abell 2744, gravitational lensing: strong, Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Abell 2744, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), cosmology: observations, galaxies:clusters:individual:Abell2744, clusters: individual: Abell 2744 [Galaxies], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Wide Field Camera 3, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present a high-precision mass model of galaxy cluster Abell 2744, based on a strong-gravitational-lensing analysis of the \emph{Hubble Space Telescope Frontier Fields} (HFF) imaging data, which now include both \emph{Advanced Camera for Surveys} and \emph{Wide-Field Camera 3} observations to the final depth. Taking advantage of the unprecedented depth of the visible and near-infrared data, we identify 34 new multiply imaged galaxies, bringing the total to 61, comprising 181 individual lensed images. In the process, we correct previous erroneous identifications and positions of multiple systems in the northern part of the cluster core. With the \textsc{Lenstool} software and the new sets of multiple images, we model the cluster using two cluster-scale dark matter halos plus galaxy-scale halos for the cluster members. Our best-fit model predicts image positions with an \emph{RMS} error of 0.69$\arcsec$, which constitutes an improvement by almost a factor of two over previous parametric models of this cluster. We measure the total projected mass inside a 200~kpc aperture as ($2.162\pm 0.005$)$\times 10^{14}M_{\odot}$, thus reaching 1\% level precision for the second time, following the recent HFF measurement of MACSJ0416.1-2403. Importantly, the higher quality of the mass model translates into an overall improvement by a factor of 4 of the derived magnification factor. % for the high-redshift lensed background galaxies. Together with our previous HFF gravitational lensing analysis, this work demonstrates that the HFF data enables high-precision mass measurements for massive galaxy clusters and the derivation of robust magnification maps to probe the early Universe., 11 pages, 4 figures, 3 tables, Accepted for publication in MNRAS. arXiv admin note: text overlap with arXiv:1405.3582
Published: 2015
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8. Spectroscopic detections of C III] λ1909 Å at z ≃ 6-7: a new probe of early star-forming galaxies and cosmic reionization

Author: Matthew A. Schenker, Brant Robertson, Brian Siana, Stéphane Charlot, Julia Gutkin, Johan Richard, Richard S. Ellis, Benjamin Clément, Aida Wofford, Daniel P. Stark, Steward Observatory (STEWARD OBSERVATORY), University of Arizona, 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), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), California Institute of Technology (CALTECH), University of California [Riverside] (UCR), University of California, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California [Riverside] (UC Riverside), and University of California (UC)
Subjects: Physics, Brightness, COSMIC cancer database, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], media_common.quotation_subject, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, Spectral line, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), Cluster (physics), Reionization, Astrophysics::Galaxy Astrophysics, media_common
Abstract: Deep spectroscopic observations of z~6.5 galaxies have revealed a marked decline with increasing redshift in the detectability of Lyman-alpha emission. While this may offer valuable insight into the end of the reionisation process, it presents a fundamental challenge to the detailed spectroscopic study of the many hundreds of photometrically-selected distant sources now being found via deep HST imaging, and particularly those bright sources viewed through foreground lensing clusters. In this paper we demonstrate the validity of a new way forward via the convincing detection of an alternative diagnostic line, CIII]1909, seen in spectroscopic exposures of two star forming galaxies at z=6.029 and 7.213. The former detection is based on a 3.5 hour X-shooter spectrum of a bright (J=25.2) gravitationally-lensed galaxy behind the cluster Abell 383. The latter detection is based on a 4.2 hour MOSFIRE spectra of one of the most distant spectroscopically confirmed galaxies, GN-108036, with J=25.2. Both targets were chosen for their continuum brightness and previously-known redshift (based on Lyman-alpha), ensuring that any CIII] emission would be located in a favorable portion of the near-infrared sky spectrum. We compare our CIII] and Lyman-alpha equivalent widths in the context of those found at z~2 from earlier work and discuss the motivation for using lines other than Lyman-alpha to study galaxies in the reionisation era., Comment: 10 pages, 6 figures, submitted to MNRAS
Published: 2015
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9. The 0.1 < z < 1.65 evolution of the bright end of the [ OII ] luminosity function

Author: Jean-Paul Kneib, Stephanie Escoffier, Jiali Wang, Jun Ma, Xu Zhou, Roland Bacon, David J. Schlegel, Eric Jullo, Laurence Tresse, Jian Ge, Michael Lesser, Anne Ealet, Yipeng Jing, Carlton M. Baugh, Timothée Delubac, Lidia Tasca, Xiaohui Fan, Donald P. Schneider, Zhou Fan, Tianmeng Zhang, Cedric G. Lacey, Olivier Ilbert, Jundan Nie, Johan Comparat, Christophe Yèche, Oliver Steele, Zhenyu Wu, Joel R. Brownstein, Nicholas P. Ross, Julien Zoubian, Hu Zou, Zhimin Zhou, Zhaoji Jiang, Stephane Arnouts, Johan Richard, Violeta Gonzalez-Perez, 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), 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), Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute for Computational Cosmology (ICC), Durham University, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), University of Utah, University of Florida [Gainesville] (UF), Drexel University, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Pennsylvania State University (Penn State), Penn State System, Institute of Cosmology and Gravitation, University of Portsmouth, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Steward Observatory (STEWARD OBSERVATORY), University of Arizona, National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), Shanghai Astronomical Observatory [Shanghai] (SHAO), Departamento de FisicaTeorica e IFT-UAM/CSIC, Universidad Autónoma de Madrid (UAM), 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), EPFL Laboratoire d’astrophysique, 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), ANR-08-BLAN-0222,BOSS,Baryon Oscillation Spectroscopic Survey(2008), European Project: 336736,EC:FP7:ERC,ERC-2013-StG,CALENDS(2013), European Project: 290975,EC:FP7:ERC,ERC-2011-ADG_20110209,LIDA(2012), Universidad Autonoma de Madrid (UAM), and UAM. Departamento de Física Teórica
Subjects: luminosity function, mass function [Galaxies], [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics::High Energy Astrophysical Phenomena, evolution. [Galaxies], Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Surveys, 01 natural sciences, Spectral line, statistics [Galaxies], surveys, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, observations [Cosmology], 010303 astronomy & astrophysics, Spectrograph, galaxies: statistics, Astrophysics::Galaxy Astrophysics, Luminosity function (astronomy), Line (formation), Physics, 010308 nuclear & particles physics, Galaxies: luminosity function, mass function, Astrophysics::Instrumentation and Methods for Astrophysics, Física, Astronomy and Astrophysics, evolution [Galaxies], Astrophysics - Astrophysics of Galaxies, luminosity function [Galaxies], Galaxy, Redshift, Baryon, galaxies: luminosity function, Space and Planetary Science, mass function, Mass function, cosmology: observations, Catalogs, galaxies: evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], catalogs, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Astronomy and Astrophysics 575 (2015): A40 reproduced with permission from Astronomy & Astrophysics, © ESO, We present the [OII] (λλ3729,3726) luminosity function measured in the redshift range 0.1, J.C. acknowledges financial support from MINECO (Spain) under project number AYA2012-31101. J.R. acknowledges support from the ERC starting grant CALENDS. J.P.K. and T.D. acknowledge support from the LIDA ERC advanced grant. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The BOSS French Participation Group is supported by Agence Nationale de la Recherche under grant ANR-08-BLAN-0222. This equipment was funded by BIS National Einfrastructure capital grant ST/K00042X/1, STFC capital grant ST/H008519/1, and STFC DiRAC Operations grant ST/K003267/1 and Durham University. DiRAC is part of the National E-Infrastructure. V.G.P. acknowledges support from a European Research Council Starting Grant (DEGAS-259586) and the Science and Technology Facilities Council (grant number ST/F001166/1)
Published: 2015
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10. New Constraints on the Faint End of the UV Luminosity Function at z ~ 7-8 Using the Gravitational Lensing of the Hubble Frontier Fields Cluster A2744

Author: Hakim Atek, Jean-Paul Kneib, Daniel Schaerer, Eiichi Egami, Priyamvada Natarajan, Mathilde Jauzac, Johan Richard, Eric Jullo, Benjamin Clément, Marceau Limousin, Harald Ebeling, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), 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), Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute for Computational Cosmology (ICC), Durham University, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), 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), Yale University [New Haven], Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), Université de Genève = University of Geneva (UNIGE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: Absolute magnitude, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], strong. [Gravitational lensing], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Luminosity, high-redshift [Galaxies], galaxies: high-redshift, 0103 physical sciences, 010303 astronomy & astrophysics, Reionization, Galaxy cluster, Astrophysics::Galaxy Astrophysics, Luminosity function (astronomy), Physics, 010308 nuclear & particles physics, gravitational lensing: strong, Astronomy and Astrophysics, evolution [Galaxies], Astrophysics - Astrophysics of Galaxies, luminosity function [Galaxies], Redshift, Galaxy, galaxies: luminosity function, Gravitational lens, Space and Planetary Science, mass function, Astrophysics of Galaxies (astro-ph.GA), galaxies: evolution
Abstract: Exploiting the power of gravitational lensing, the Hubble Frontier Fields (HFF) program aims at observing six massive galaxy clusters to explore the distant Universe far beyond the depth limits of blank field surveys. Using the complete Hubble Space Telescope observations of the first HFF cluster Abell 2744, we report the detection of 50 galaxy candidates at $z \sim 7$ and eight candidates at $z \sim 8$ in a total survey area of 0.96 arcmin$^{2}$ in the source plane. Three of these galaxies are multiply-imaged by the lensing cluster. Using an updated model of the mass distribution in the cluster we were able to calculate the magnification factor and the effective survey volume for each galaxy in order to compute the ultraviolet galaxy luminosity function at both redshifts 7 and 8. Our new measurements extend the $z \sim 7$ UV LF down to an absolute magnitude of $M_{UV} \sim -15.5$. We find a characteristic magnitude of $M^{\star}_{UV}=-20.63^{+0.69}_{-0.56}$ mag and a faint-end slope $\alpha = -1.88^{+0.17}_{-0.20}$ close to previous determinations in blank fields. We show here for the first time that this slope remains steep down to very faint luminosities of 0.01$L^{\star}$. Although prone to large uncertainties, our results at $z \sim 8$ also seem to confirm a steep faint-end slope below 0.1$L^{\star}$. The HFF program is therefore providing an extremely efficient way to study the faintest galaxy populations at $z > 7$ that would otherwise be inaccessible with current instrumentation. The full sample of six galaxy clusters will provide yet better constraints on the build-up of galaxies at early epochs and their contribution to cosmic reionization., Comment: 14 pages, 9 figures, submitted to ApJ
Published: 2015
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11. ALMA detection of [C II] 158 µm emission from a strongly lensed z = 2.013 star-forming galaxy

Author: Daniel Schaerer, Richard S. Ellis, Antonio Cava, Frédéric Boone, Miroslava Dessauges-Zavadsky, M. Zamojski, Eiichi Egami, Johan Richard, Francoise Combes, T. D. Rawle, T. A. Jones, Panos Sklias, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Department of Physics [Santa Barbara] (PHYSICS-UCSB), University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université de Genève (UNIGE), University of California [Santa Barbara] (UCSB), University of California-University of California, 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), École normale supérieure - Paris (ENS Paris), and Chaire Galaxies et cosmologie
Subjects: Physics, Active galactic nucleus, 010308 nuclear & particles physics, Star formation, Strong gravitational lensing, Plateau de Bure Interferometer, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Redshift, Galaxy, Luminosity, Interstellar medium, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: International audience; Aims. Our objectives are to determine the properties of the interstellar medium (ISM) and of star formation in typical star-forming galaxies at high redshift. Methods. Following up on our previous multi-wavelength observations with HST, Spitzer, Herschel, and the Plateau de Bure Interferometer (PdBI), we have studied a strongly lensed z = 2.013 galaxy, the arc behind the galaxy cluster MACS J0451+0006, with ALMA to measure the [C ] 158 µm emission line, one of the main coolants of the ISM. Results. Emission of the [C ] line from the southern part of this galaxy is detected at 10σ. Taking strong gravitational lensing into account, which provides a magnification of µ = 49, the intrinsic lensing-corrected [C ] luminosity is L [CII] = 1.2 × 10 8 L. The observed ratio of [C ]-to-IR emission, L [CII] /L FIR ≈ (1.2−2.4) × 10 −3 , is found to be similar to that in nearby galaxies. The same also holds for the observed ratio L [CII] /L CO = 2.3 × 10 3 , which is comparable to that of star-forming galaxies and active galaxy nuclei (AGN) at low redshift. Conclusions. We utilize strong gravitational lensing to extend diagnostic studies of the cold ISM to an order of magnitude lower lumi-nosity (L IR ∼ (1.1−1.3) × 10 11 L) and SFR than previous work at high redshift. While larger samples are needed, our results provide evidence that the cold ISM of typical high-redshift galaxies has physical characteristics similar to normal star-forming galaxies in the local Universe.
Published: 2015
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12. Correction: Enhancement of charge photo-generation and transport via an internal network of Sb2Se3/Cu2GeSe3 heterojunctions

Author: Jean-Jacques Simon, Xianghua Zhang, Qun Luo, Hui Yang, Hongli Ma, Michel Cathelinaud, Laurent Calvez, Xianping Fan, Bo Fan, Qianhong Shen, Xusheng Qiao, Yang Xu, Fudan University [Shanghai], Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), National Engineering Research Center for Information Technology in Agriculture [Beijing] (NERCITA), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Department of Materials Science and Engineering, Zhejiang University, Biomathematics Research Centre, University of Canterbury [Christchurch], Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Photocurrent, Materials science, Renewable Energy, Sustainability and the Environment, business.industry, Nanoparticle, Chalcogenide glass, Biasing, Heterojunction, Charge (physics), 02 engineering and technology, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, law.invention, law, Optoelectronics, General Materials Science, Charge carrier, Crystallization, 0210 nano-technology, business
Abstract: An interpenetrating iodine-doped-Sb2Se3/Cu2GeSe3 heterojunction network has been fabricated by controlling the crystallization of a chalcogenide glass. These two crystals absorb strongly and widely the solar spectrum for efficient charge photo-generation, and the heterojunction formed by these two crystals greatly promotes the charge separation. More importantly, these free charge carriers can be efficiently transported through the conductive channels formed by the oriented Cu2GeSe3 nanoparticles aggregated between the Sb2Se3 rods. The photo-electrochemical measurement shows that this structure results in a photocurrent of 74 μA cm−2 and a photo-current/dark-current ratio over 12 times at a bias voltage of −0.6 V and under an illumination of 250 W cm−2. This photocurrent is at least 100 times higher than any of these two crystals individually.
Published: 2015
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13. Hubble Frontier Fields: the geometry and dynamics of the massive galaxy cluster merger MACSJ0416.1−2403

Author: Marceau Limousin, H. Atek, Eiichi Egami, Eric Jullo, Benjamin Clément, Dominique Eckert, Markus Rexroth, Priyamvada Natarajan, Johan Richard, Mathilde Jauzac, Benoit Neichel, David Harvey, Harald Ebeling, Kenda Knowles, Richard Massey, Jean-Paul Kneib, Institute for Computational Cosmology (ICC), Durham University, 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 = University of Geneva (UNIGE), Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, University of Edinburgh, AUTRES, Yale University [New Haven], Université de Genève (UNIGE), 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), School of Mathematics and Statistics [Sydney] (UNSW), University of New South Wales [Sydney] (UNSW), and 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)
Subjects: galaxies: clusters: individual, Cosmology and Nongalactic Astrophysics (astro-ph.CO), [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Strong gravitational lensing, Dark matter, galaxies: clusters. [X-rays], FOS: Physical sciences, Geometry, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, strong [Gravitational lensing], 01 natural sciences, dark matter, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], clusters: individual [Galaxies], gravitational lensing: weak, 0103 physical sciences, Brightest cluster galaxy, 010303 astronomy & astrophysics, Galaxy cluster, Weak gravitational lensing, Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, Astronomy, Velocity dispersion, gravitational lensing: strong, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Abell 2744, Space and Planetary Science, X-rays: galaxies: clusters, Astrophysics of Galaxies (astro-ph.GA), weak [Gravitational lensing], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We use a joint optical/X-ray analysis to constrain the geometry and history of the ongoing merging event in the massive galaxy cluster MACSJ0416.1-2403 (z=0.397). Our investigation of cluster substructure rests primarily on a combined strong- and weak-lensing mass reconstruction based on the deep, high-resolution images obtained for the Hubble Frontier Fields initiative. To reveal the system's dynamics, we complement this lensing analysis with a study of the intra-cluster gas using shallow Chandra data, and a three-dimensional model of the distribution and motions of cluster galaxies derived from over 100 spectroscopic redshifts. The multi-scale grid model obtained from our combined lensing analysis extends the high-precision strong-lensing mass reconstruction recently performed to cluster-centric distances of almost 1 Mpc. Our analysis detects the two well known mass concentrations in the cluster core. A pronounced offset between collisional and collisionless matter is only observed for the SW cluster component, while excellent alignment is found for the NE cluster. Both the lensing analysis and the distribution of cluster light strongly suggest the presence of a third massive structure, almost 2 arcmin SW of the cluster centre. Since no X-ray emission is detected in this region, we conclude that this structure is non-virialised and speculate that it might be part of a large-scale filament almost aligned with our line of sight. Combining all evidence from the distribution of dark and luminous matter, we propose two alternative scenarios for the trajectories of the components of MACSJ0416.1-2403. Upcoming deep X-ray observations that allow the detection of shock fronts, cold cores, and sloshing gas (all key diagnostics for studies of cluster collisions) will allow us to test, and distinguish between these two scenarios., Comment: Submitted to MNRAS - 17 pages, 13 figures, 3 tables
Published: 2015
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14. Ultraviolet emission lines in young low-mass galaxies at z ≃ 2: physical properties and implications for studies at z > 7

Author: Stark, Daniel P., Richard, Johan, Siana, Brian, Charlot, Stéphane, Freeman, William R., Gutkin, Julia, Wofford, Aida, Robertson, Brant, Amanullah, Rahman, Watson, Darach, Milvang-Jensen, Bo, Steward Observatory (STEWARD OBSERVATORY), University of Arizona, 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), University of California [Riverside] (UCR), University of California, Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), AlbaNova University Center (ALBANOVA), Stockholm University, Dark Cosmology Centre (DARK), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), 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), University of California [Riverside] (UC Riverside), University of California (UC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], and University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)
Subjects: [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: International audience; We present deep spectroscopy of 17 very low mass (M* ~= 2.0 × 106-1.4 × 109 M&sun;) and low luminosity (MUV ~= -13.7 to -19.9) gravitationally lensed galaxies in the redshift range z ~= 1.5-3.0. Deep rest-frame ultraviolet spectra reveal large equivalent width emission from numerous emission lines (N IV], O III], C IV, Si III], C III]) which are rarely seen in individual spectra of more massive star-forming galaxies. C III] is detected in 16 of 17 low-mass star-forming systems with rest-frame equivalent widths as large as 13.5 Å. Nebular C IV emission is present in the most extreme C III] emitters, requiring an ionizing source capable of producing a substantial component of photons with energies in excess of 47.9 eV. Photoionization models support a picture whereby the large equivalent widths are driven by the increased electron temperature and enhanced ionizing output arising from metal-poor gas and stars (0.04-0.13 Z&sun;), young stellar populations (6-50 Myr), and large ionization parameters (log U = -2.16 to -1.84). The young ages implied by the emission lines and continuum spectral energy distributions (SEDs) indicate that the extreme line emitters in our sample are in the midst of a significant upturn in their star formation activity. The low stellar masses, blue UV colours, and large specific star formation rates of our sample are similar to those of typical z ≳ 6 galaxies. Given the strong attenuation of Lyalpha in z ≳ 6 galaxies, we suggest that C III] is likely to provide our best probe of early star-forming galaxies with ground-based spectrographs and one off the most efficient means of confirming z ≳ 10 galaxies with the James Webb Space Telescope.
Published: 2014

15. The near-infrared spectral energy distribution of β Pictoris b

Author: Gael Chauvin, A-M. Lagrange, Derek Homeier, Anthony Boccaletti, C. Mordasini, H. Beust, F. Allard, Sylvestre Lacour, Daniel Apai, Julien Girard, Daniel Rouan, Mickael Bonnefoy, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire 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), 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), Physikalisches Institut [Bern], Universität Bern [Bern], European Southern Observatory (ESO), Zentrum für Astronomie der Universität Heidelberg (ZAH), Universität Heidelberg [Heidelberg], Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Observatoire de Paris - Site de Paris (OP), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Observatoire 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), 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), Universität Bern [Bern] (UNIBE), and Universität Heidelberg [Heidelberg] = Heidelberg University
Subjects: Physics, [PHYS]Physics [physics], Debris disk, 010308 nuclear & particles physics, Gas giant, Astronomy and Astrophysics, Context (language use), Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Luminosity, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Planetary mass, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics - Earth and Planetary Astrophysics
Abstract: A gas giant planet has previously been directly seen orbiting at 8-10 AU within the debris disk of the ~12 Myr old star {\beta} Pictoris. The {\beta} Pictoris system offers the rare opportunity to study the physical and atmospheric properties of an exoplanet placed on a wide orbit and to establish its formation scenario. We obtained J (1.265 {\mu}m), H (1.66 {\mu}m), and M' (4.78 {\mu}m) band angular differential imaging of the system between 2011 and 2012. We detect the planetary companion in our four-epoch observations. We estimate J = 14.0 +- 0.3, H = 13.5 +- 0.2, and M' = 11.0 +- 0.3 mag. Our new astrometry consolidates previous semi-major axis (sma=8-10 AU) and excentricity (e = 6MJup and the initial entropies to values (Sinit >= 9.3Kb/baryon), intermediate between those considered for cold/hot-start models, but likely closer to those of hot-start models., Comment: 19 pages, accepted in Astronomy and Astrophysics
Published: 2013
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16. The position of β Pictoris b position relative to the debris disk

Author: Julien Milli, A. Boccaletti, David Mouillet, J. C. Augereau, M. Bonnefoy, J. H. Girard, Sylvestre Lacour, G. Chauvin, Daniel Apai, Anne-Marie Lagrange, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Departement de recherche SPAtiale (DESPA), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, [PHYS]Physics [physics], Debris disk, Inclined orbit, 010504 meteorology & atmospheric sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Orientation (vector space), Space and Planetary Science, Planet, Position (vector), 0103 physical sciences, Beta Pictoris, Beta (velocity), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Context. We detected in 2009 a giant, close-by planet orbiting {\beta} Pic, a young star surrounded with a disk, extensively studied for more than 20 years. We showed that if located on an inclined orbit, the planet could explain several peculiarities of {\beta} Pictoris system. However, the available data did not permit to measure the inclination of {\beta} Pic b with respect to the disk, and in particular to establish in which component of the disk - the main, extended disk or the inner inclined component/disk-, the planet was located. Comparison between the observed planet position and the disk orientation measured on previous imaging data was not an option because of potential biases in the measurements. Aims. Our aim is to measure precisely the planet location with respect to the dust disk using a single high resolution image, and correcting for systematics or errors that degrades the precision of the disk and planet relative position measurements. Methods. We gathered new NaCo data at Ks band, with a set-up optimized to derive simultaneously the orientation(s) of the disk(s) and that of the planet. Results. We show that the projected position of {\beta} Pic b is above the midplane of the main disk. With the current data and knowledge on the system, this implies that {\beta} Pic b cannot be located in the main disk. The data rather suggest the planet being located in the inclined component.
Published: 2012
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17. Direct constraint on the distance of Gamma2 Velorum from AMBER/VLTI observations

Author: F. Millour, R. G. Petrov, O. Chesneau, D. Bonneau, L. Dessart, C. Bechet, I. Tallon-Bosc, M. Tallon, E. Thiébaut, F. Vakili, F. Malbet, D. Mourard, P. Antonelli, U. Beckmann, Y. Bresson, A. Chelli, M. Dugué, G. Duvert, S. Gennari, L. Glück, P. Kern, S. Lagarde, E. Le Coarer, F. Lisi, K. Perraut, P. Puget, F. Rantakyrö, S. Robbe-Dubois, A. Roussel, E. Tatulli, G. Weigelt, G. Zins, M. Accardo, B. Acke, K. Agabi, E. Altariba, B. Arezki, E. Aristidi, C. Baffa, J. Behrend, T. Blöcker, S. Bonhomme, S. Busoni, F. Cassaing, J.-M. Clausse, J. Colin, C. Connot, A. Delboulbé, A. Domiciano de Souza, T. Driebe, P. Feautrier, D. Ferruzzi, T. Forveille, E. Fossat, R. Foy, D. Fraix-Burnet, A. Gallardo, E. Giani, C. Gil, A. Glentzlin, M. Heiden, M. Heininger, O. Hernandez Utrera, K.-H. Hofmann, D. Kamm, M. Kiekebusch, S. Kraus, D. Le Contel, J.-M. Le Contel, T. Lesourd, B. Lopez, M. Lopez, Y. Magnard, A. Marconi, G. Mars, G. Martinot-Lagarde, P. Mathias, P. Mège, J.-L. Monin, D. Mouillet, E. Nussbaum, K. Ohnaka, J. Pacheco, C. Perrier, Y. Rabbia, S. Rebattu, F. Reynaud, A. Richichi, A. Robini, M. Sacchettini, D. Schertl, M. Schöller, W. Solscheid, A. Spang, P. Stee, P. Stefanini, D. Tasso, L. Testi, O. von der Lühe, J.-C. Valtier, M. Vannier, N. Ventura, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Gemini (LG), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Radioastronomie (MPIFR), European Southern Observatory (ESO), PHOTONIQUE, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), AMBER, Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), ONERA, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Observable, Ranging, Astrophysics, Spectral bands, Position angle, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, 0103 physical sciences, Binary system, 010303 astronomy & astrophysics
Abstract: International audience; In this work, we present the first AMBER observations, of the Wolf-Rayet and O (WR+O) star binary system y² Velorum. The AMBER instrument was used with the telescopes UT2, UT3, and UT4 on baselines ranging from 46m to 85m. It delivered spectrally dispersed visibilities, as well as differential and closure phases, with a resolution R = 1500 in the spectral band 1.95-2.17 micron. We interpret these data in the context of a binary system with unresolved components, neglecting in a first approximation the wind-wind collision zone flux contribution. We show that the AMBER observables result primarily from the contribution of the individual components of the WR+O binary system. We discuss several interpretations of the residuals, and speculate on the detection of an additional continuum component, originating from the free-free emission associated with the wind-wind collision zone (WWCZ), and contributing at most to the observed K-band flux at the 5% level. The expected absolute separation and position angle at the time of observations were 5.1±0.9mas and 66±15° respectively. However, we infer a separation of 3.62+0.11-0.30 mas and a position angle of 73+9-11°. Our analysis thus implies that the binary system lies at a distance of 368+38-13 pc, in agreement with recent spectrophotometric estimates, but significantly larger than the Hipparcos value of 258+41-31 pc.
Published: 2007
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18. [C II] emission in z similar to 6 strongly lensed, star-forming galaxies

Author: Knudsen, Kirsten K., Richard, Johan, Kneib, Jean-Paul, Jauzac, Mathilde, Clément, Benjamin, Drouart, Guillaume, Egami, Eiichi, Lindroos, Lukas, Alfa, Rheinische Friedrich-Wilhelms-Universität Bonn, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Institute for Computational Cosmology (ICC), Durham University, European Southern Observatory (ESO), Steward Observatory (STEWARD OBSERVATORY), University of Arizona, École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and 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)
Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], galaxies: high-redshift, galaxies: formation, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], galaxies: evolution, submillimetre: galaxies, galaxies: ISM
Abstract: International audience; The far-infrared fine-structure line [C II] at 1900.5 GHz is known to be one of the brightest cooling lines in local galaxies, and therefore it has been suggested to be an efficient tracer for star formation in very high redshift galaxies. However, recent results for galaxies at z \textgreater 6 have yielded numerous non-detections in star-forming galaxies, except for quasars and submillimetre galaxies. We report the results of ALMA observations of two lensed, star-forming galaxies at z = 6.029 and z = 6.703. The galaxy A383-5.1 (star formation rate [SFR] of 3.2 M-circle dot yr(-1) and magnification of mu = 11.4 +/- 1.9) shows a line detection with L-[C II] = 8.9 x 10(6) L-circle dot, making it the lowest L-[C II] detection at z \textgreater 6. For MS0451-H (SFR = 0.4 M-circle dot yr(-1) and mu = 100 +/- 20) we provide an upper limit of L-[C II] \textless 3 x 10(5) L-circle dot, which is 1 dex below the local SFR-L-[C II] relations. The results are consistent with predictions for low-metallicity galaxies at z \textgreater 6; however, other effects could also play a role in terms of decreasing L-[CII]. The detection of A383-5.1 is encouraging and suggests that detections are possible, but much fainter than initially predicted.
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19. Wolf-Rayet stars probed by AMBER/VLTI

Author: Luc Dessart, Olivier Chesneau, Daniel Bonneau, Thomas Driebe, Karl-Heinz Hofmann, Gerd Weigelt, Florentin Millour, Romain Petrov, Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire Hippolyte Fizeau (FIZEAU), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Steward Observatory (STEWARD OBSERVATORY), and University of Arizona
Subjects: Physics, Orbital elements, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics (astro-ph), Techniques: image processing, FOS: Physical sciences, Astrophysics, Stellar classification, Kinetic energy, 01 natural sciences, Luminosity, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Interferometry, Stars, Wolf–Rayet star, 13. Climate action, Methods: data analysis, Instrumentation: interferometers, 0103 physical sciences, Emission spectrum, 010303 astronomy & astrophysics
Abstract: Massive stars deeply influence their surroundings by their luminosity and the injection of kinetic energy. So far, they have mostly been studied with spatially unresolved observations, although evidence of geometrical complexity of their wind are numerous. Interferometry can provide spatially resolved observations of massive stars and their immediate vicinity. Specific geometries (disks, jets, latitude-dependent winds) can be probed by this technique. The first observation of a Wolf-Rayet (WR) star (\gamma^2 Vel) with the AMBER/VLTI instrument yielded to a re-evaluation of its distance and an improved characterization of the stellar components, from a very limited data-set. This motivated our team to increase the number of WR targets observed with AMBER. We present here new preliminary results that encompass several spectral types, ranging from early WN to evolved dusty WC. We present unpublished data on WR79a, a massive star probably at the boundary between the O and Wolf- Rayet type, evidencing some Wolf-Rayet broad emission lines from an optically thin wind. We also present new data obtained on \gamma^2 Vel that can be compared to the up-to-date interferometry-based orbital parameters from North et al. (2007). We discuss the presence of a wind-wind collision zone in the system and provide preliminary analysis suggesting the presence of such a structure in the data. Then, we present data obtained on 2 dusty Wolf-Rayet stars: WR48a-b and WR118, the latter exhibiting some clues of a pinwheel-like structure from the visibility variations., Comment: This paper will be published in the proceeding of SPIE ``astronomical Telescopes and Instrumentation: Optical and Infrared Interferometry''

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19 results on '"Steward Observatory (STEWARD OBSERVATORY)"'

1. Hubble Frontier Fields: predictions for the return of SN Refsdal with the MUSE and GMOS spectrographs

2. Mechanism and kinetics of electrocarboxylation of aromatic ketones in ionic liquid

3. Shadows and spirals in the protoplanetary disk HD 100453

4. First light of the VLT planet finder SPHERE. III. New spectrophotometry and astrometry of the HR 8799 exoplanetary system

5. SN 1994W: an interacting supernova or two interacting shells?

6. ARE ULTRA-FAINT GALAXIES AT z = 6–8 RESPONSIBLE FOR COSMIC REIONIZATION? COMBINED CONSTRAINTS FROM THE HUBBLE FRONTIER FIELDS CLUSTERS AND PARALLELS

7. Hubble Frontier Fields: a high-precision strong-lensing analysis of the massive galaxy cluster Abell 2744 using similar to 180 multiple images

8. Spectroscopic detections of C III] λ1909 Å at z ≃ 6-7: a new probe of early star-forming galaxies and cosmic reionization

9. The 0.1 < z < 1.65 evolution of the bright end of the [ OII ] luminosity function

10. New Constraints on the Faint End of the UV Luminosity Function at z ~ 7-8 Using the Gravitational Lensing of the Hubble Frontier Fields Cluster A2744

11. ALMA detection of [C II] 158 µm emission from a strongly lensed z = 2.013 star-forming galaxy

12. Correction: Enhancement of charge photo-generation and transport via an internal network of Sb2Se3/Cu2GeSe3 heterojunctions

13. Hubble Frontier Fields: the geometry and dynamics of the massive galaxy cluster merger MACSJ0416.1−2403

14. Ultraviolet emission lines in young low-mass galaxies at z ≃ 2: physical properties and implications for studies at z > 7

15. The near-infrared spectral energy distribution of β Pictoris b

16. The position of β Pictoris b position relative to the debris disk

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

18. [C II] emission in z similar to 6 strongly lensed, star-forming galaxies

19. Wolf-Rayet stars probed by AMBER/VLTI

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