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8 results on '"Vincent Lapeyrere"'

1. MOLsphere and pulsations of the Galactic Center’s red supergiant GCIRS 7 from VLTI/GRAVITY

Author

Karine Perraut, Xavier Haubois, Jason Dexter, Christian Straubmeier, Th. Henning, F. H. Vincent, Linda J. Tacconi, Eckhard Sturm, Idel Waisberg, Stefan Hippler, Guy Perrin, Vincent Lapeyrere, J. Sanchez-Bermudez, Felix Widmann, Andreas Kaufer, Thomas Ott, A. Drescher, O. Pfuhl, Julien Woillez, G. Rodríguez-Coira, Laurent Jocou, Jean-Philippe Berger, Eric Gendron, Lieselotte Jochum, Gérard Zins, S. von Fellenberg, Paulo J. V. Garcia, Sylvestre Lacour, Stefan Gillessen, M. Nowak, N. M. Förster Schreiber, Julia Stadler, Matthew Horrobin, Feng Gao, António Amorim, Frank Eisenhauer, Pierre Léna, Odele Straub, J.-B. Le Bouquin, Erich Wiezorrek, M. Habibi, Reinhard Genzel, Silvia Scheithauer, H. Bonnet, Thibaut Paumard, Pierre Kervella, A. Jiménez-Rosales, Andreas Eckart, Ekkehard Wieprecht, S. Yazici, T. Taro Shimizu, M. Bauböck, Roberto Abuter, Jinyi Shangguan, Wolfgang Brandner, Yann Clénet, P. T. de Zeeuw, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), 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)-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), Département de Chimie Moléculaire - Ingéniérie et Intéractions BioMoléculaires (DCM - I2BM), Département de Chimie Moléculaire (DCM), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Extraterrestrische Physik (MPE), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Wageningen University and Research [Wageningen] (WUR), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Poznan Technical University, Max Planck Institute for Astronomy (MPIA), GRAVITY Collaboration, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics [LESIA], Récepteurs nucléaires, maladies cardiovasculaires et diabète - U 1011 [RNMCD], Département de Chimie Moléculaire - Ingéniérie et Intéractions BioMoléculaires [DCM - I2BM], Max-Planck-Institut für Extraterrestrische Physik [MPE], Laboratoire d'études spatiales et d'instrumentation en astrophysique [LESIA], Wageningen University and Research [Wageningen] [WUR], European Southern Observatory [Santiago] [ESO], European Southern Observatory [ESO], Institut Européen des membranes [IEM], Institut de Planétologie et d'Astrophysique de Grenoble [IPAG], Max Planck Institute for Astronomy [MPIA], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Universidade de Lisboa = University of Lisbon (ULISBOA), Centro de Astrofísica e Gravitação (CENTRA), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, 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, Leiden University, University of Colorado [Boulder], Universität zu Köln = University of Cologne, Max Planck Institute for Radio Astronomy, Universidade do Porto = University of Porto, University of California [Berkeley] (UC Berkeley), University of California (UC), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Weizmann Institute of Science [Rehovot, Israël], Sciences, EDP, Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut Européen des membranes (IEM), and Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Galaxy: nucleus, techniques: interferometric, stars: individual: GCIRS 7, stars: fundamental parameters, supergiants, Astrophysics - astrophysics of galaxies, Extinction (astronomy), Continuum (design consultancy), FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, Astrophysics - solar and stellar astrophysics, 0103 physical sciences, Red supergiant, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Photosphere, 010308 nuclear & particles physics, Galactic Center, Astronomy and Astrophysics, Stars, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Supergiant, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

GCIRS 7, the brightest star in the Galactic central parsec, formed $6\pm2$ Myr ago together with dozens of massive stars in a disk orbiting the central black-hole. It has been argued that GCIRS 7 is a pulsating body, on the basis of photometric variability. We present the first medium-resolution ($R=500$), K-band spectro-interferometric observations of GCIRS 7, using the GRAVITY instrument with the four auxiliary telescopes of the ESO VLTI. We looked for variations using two epochs, namely 2017 and 2019. We find GCIRS 7 to be moderately resolved with a uniform-disk photospheric diameter of $\theta^*_\text{UD}=1.55 \pm 0.03$ mas ($R^*_\text{UD}=1368 \pm 26$ $R_\odot$) in the K-band continuum. The narrow-band uniform-disk diameter increases above 2.3 $\mu$m, with a clear correlation with the CO band heads in the spectrum. This correlation is aptly modeled by a hot ($T_\text{L}=2368\pm37$ K), geometrically thin molecular shell with a diameter of $\theta_\text{L}=1.74\pm0.03$ mas, as measured in 2017. The shell diameter increased ($\theta_\text{L}=1.89\pm0.03$ mas), while its temperature decreased ($T_\text{L}=2140\pm42$ K) in 2019. In contrast, the photospheric diameter $\theta^*_\text{UD}$ and the extinction up to the photosphere of GCIRS 7 ($A_{\mathrm{K}_\mathrm{S}}=3.18 \pm 0.16$) have the same value within uncertainties at the two epochs. In the context of previous interferometric and photo-spectrometric measurements, the GRAVITY data allow for an interpretation in terms of photospheric pulsations. The photospheric diameter measured in 2017 and 2019 is significantly larger than previously reported using the PIONIER instrument ($\theta_*=1.076 \pm 0.093$ mas in 2013 in the H band). The parameters of the photosphere and molecular shell of GCIRS 7 are comparable to those of other red supergiants that have previously been studied using interferometry., Comment: 12 pages, 11 figures, 3 tables. Accepted for publication in Astronomy and Astrophysics (A&A)

Published
2021

2. The mass of β Pictoris c from β Pictoris b orbital motion

Author

Matthias Samland, Anne-Lise Maire, David Mouillet, Andreas Eckart, Valentin Christiaens, Julien Woillez, Sarah Blunt, K. Perraut, T. Paumard, T. Ott, Myriam Benisty, E. Nasedkin, A. Mérand, Z. Hubert, Stefan Hippler, Frank Eisenhauer, Roderick Dembet, Gilles Otten, F. H. Vincent, Pierre Léna, Jinyi Shangguan, Miriam Keppler, Ekkehard Wieprecht, G. Bourdarot, M. Houllé, Odele Straub, Alexander J. Bohn, M. Nowak, Felix Widmann, K. Ward-Duong, P. T. de Zeeuw, J.-B. Le Bouquin, Julia Stadler, T. Taro Shimizu, A. Boccaletti, David K. Sing, Ji Wang, Linda J. Tacconi, Arthur Vigan, Elodie Choquet, Jens Kammerer, Claudia Paladini, J. Rameau, R. J. García López, Xavier Haubois, E. Rickman, Guy Perrin, J. P. Berger, Wolfgang Brandner, Eric Gendron, G. Heißel, H. Bonnet, Laurent Jocou, A. Cridland, S. D. von Fellenberg, Pierre Kervella, R. Asensio-Torres, G. Rousset, O. Pfuhl, Erich Wiezorrek, M. Bonnefoy, Y. Clénet, Senol Yazici, R. Abuter, John D. Monnier, Laura Kreidberg, Paulo J. V. Garcia, Zafar Rustamkulov, Tomas Stolker, Gilles Duvert, Paul Mollière, H. Beust, Eckhard Sturm, António Amorim, Anne-Marie Lagrange, Paola Caselli, Christian Straubmeier, Th. Henning, G. Chauvin, Benjamin Charnay, Sylvestre Lacour, E. F. van Dishoeck, Jason Dexter, Stefan Gillessen, André Young, D. Lutz, V. Coudé du Foresto, R. Genzel, Feng Gao, J. H. Girard, Faustine Cantalloube, L. Rodet, Sasha Hinkley, A. Drescher, Vincent Lapeyrere, Laurent Pueyo, Matthew Horrobin, M. L. Bolzer, 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), 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)-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), MacoPharma, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Departamento de Astronomía, Universidad de Chile = University of Chile [Santiago] (UCHILE), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, European Southern Observatory (ESO), Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Max-Planck-Institut für Astronomie (MPIA), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Service de Pathologie respiratoire et allergologie [CHU Limoges], CHU Limoges, University of Auckland [Auckland], the GRAVITY Collaboration, 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), 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, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Harvard University-Smithsonian Institution, and Université de Genève = University of Geneva (UNIGE)

Subjects
Astrophysics - instrumentation and methods for astrophysics, planets and satellites: detection, 010504 meteorology & atmospheric sciences, Astrophysics, Astrophysics - Earth and planetary astrophysics, 01 natural sciences, High angular resolution, Planet, instrumentation: high angular resolution, 0103 physical sciences, Beta Pictoris, 10. No inequality, instrumentation: interferometers, 010303 astronomy & astrophysics, Instrumentation, 0105 earth and related environmental sciences, Orbital elements, Physics, Interferometers, Astronomy and Astrophysics, Astrometry, Exoplanet, Radial velocity, Detection, Space and Planetary Science, Orbital motion, Planets and satellites, Eccentricity (mathematics), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Aims.We aim to demonstrate that the presence and mass of an exoplanet can now be effectively derived from the astrometry of another exoplanet.Methods.We combined previous astrometry ofβPictoris b with a new set of observations from the GRAVITY interferometer. The orbital motion ofβPictoris b is fit using Markov chain Monte Carlo simulations in Jacobi coordinates. The inner planet,βPictoris c, was also reobserved at a separation of 96 mas, confirming the previous orbital estimations.Results.From the astrometry of planet b only, we can (i) detect the presence ofβPictoris c and (ii) constrain its mass to 10.04−3.10+4.53MJup. If one adds the astrometry ofβPictoris c, the mass is narrowed down to 9.15−1.06+1.08MJup. The inclusion of radial velocity measurements does not affect the orbital parameters significantly, but it does slightly decrease the mass estimate to 8.89−0.75+0.75MJup. With a semimajor axis of 2.68 ± 0.02 au, a period of 1221 ± 15 days, and an eccentricity of 0.32 ± 0.02, the orbital parameters ofβPictoris c are now constrained as precisely as those ofβPictoris b. The orbital configuration is compatible with a high-order mean-motion resonance (7:1). The impact of the resonance on the planets’ dynamics would then be negligible with respect to the secular perturbations, which might have played an important role in the eccentricity excitation of the outer planet.

Published
2021

3. FIRST, a pupil-remapping fiber interferometer at the Subaru Telescope: on-sky results

Author

Elsa Huby, Olivier Guyon, Vincent Lapeyrere, Franck Marchis, Takayuki Kotani, Guillermo Martin, Julien Lozi, Kevin Barjot, Sébastien Vievard, Daniel Rouan, Gaspard Duchene, Vincent Deo, Sylvestre Lacour, Nick Cvetojevic, Guy Perrin, Nemanja Jovanovic, Tuthill, Peter G., Mérand, Antoine, and Sallum, Stephanie

Subjects
Physics, Diffraction, media_common.quotation_subject, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, 010309 optics, Telescope, Interferometry, law, Sky, 0103 physical sciences, Extremely Large Telescope, Astrophysics::Solar and Stellar Astrophysics, Angular resolution, Astrophysics::Earth and Planetary Astrophysics, Adaptive optics, Subaru Telescope, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, media_common
Abstract

FIRST, the Fibered Imager foR a Single Telescope, is a spectro-imager using single-mode fibers for pupil remap- ping, allowing measurements beyond the telescope diffraction limit. Integrated on the Subaru Coronagraphic Extreme Adaptive Optics instrument at the Subaru Telescope, it benefits from a very stable visible light wave- front allowing to acquire long exposure and operate on significantly fainter sources than previously possible. On-sky results demonstrated the ability of the instrument to detect stellar companions separated 43mas in the case of the Capella binary system. A similar approach on an extremely large telescope would offer unique scientific opportunities for companion detection and characterization at very high angular resolution.

Published
2020

4. Test of the Einstein Equivalence Principle near the Galactic Center Supermassive Black Hole

Author

N. M. Förster Schreiber, Karine Perraut, Ekkehard Wieprecht, Christian Straubmeier, Stefan Hippler, Th. Henning, Thibaut Paumard, Frank Eisenhauer, Felix Widmann, Pierre Kervella, Laurent Jocou, Paulo J. V. Garcia, Pierre Léna, Silvia Scheithauer, Matthew Horrobin, M. Bauböck, Thomas Ott, Maryam Habibi, Oliver Pfuhl, Jason Dexter, Linda J. Tacconi, S. von Fellenberg, A. Jimenez Rosales, Yann Clénet, P. T. de Zeeuw, Sylvestre Lacour, Gilles Duvert, Andreas Eckart, Guy Perrin, Amiel Sternberg, Senol Yazici, Eckhard Sturm, Erich Wiezorrek, Eric Gendron, Idel Waisberg, M. Ebert, Reinhard Genzel, F. Vincent, António Amorim, Sebastian Rabien, G. Rodríguez-Coira, Z. Hubert, Xavier Haubois, Vincent Lapeyrere, Odele Straub, J.-B. Le Bouquin, Wolfgang Brandner, G. Rousset, Feng Gao, V. Coudé du Foresto, Jean-Philippe Berger, Stefan Gillessen, 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)-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), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), GRAVITY, Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
General Physics and Astronomy, FOS: Physical sciences, Astrophysics, General Relativity and Quantum Cosmology (gr-qc), Gravitation and Astrophysics, 7. Clean energy, 01 natural sciences, General Relativity and Quantum Cosmology, Gravitational potential, 0103 physical sciences, Equivalence principle, 010306 general physics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, Supermassive black hole, Galactic Center, White dwarf, Astrophysics - Astrophysics of Galaxies, Redshift, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Black hole, Sagittarius A, Astrophysics of Galaxies (astro-ph.GA), Physics::Space Physics, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

During its orbit around the four million solar mass black hole Sagittarius A* the star S2 experiences significant changes in gravitational potential. We use this change of potential to test one part of the Einstein equivalence principle: the local position invariance (LPI). We study the dependency of different atomic transitions on the gravitational potential to give an upper limit on violations of the LPI. This is done by separately measuring the redshift from hydrogen and helium absorption lines in the stellar spectrum during its closest approach to the black hole. For this measurement we use radial velocity data from 2015 to 2018 and combine it with the gravitational potential at the position of S2, which is calculated from the precisely known orbit of S2 around the black hole. This results in a limit on a violation of the LPI of $|\beta_{He}-\beta_{H}| = (2.4 \pm 5.1) \cdot 10^{-2}$. The variation in potential that we probe with this measurement is six magnitudes larger than possible for measurements on Earth, and a factor ten larger than in experiments using white dwarfs. We are therefore testing the LPI in a regime where it has not been tested before., Comment: Accepted for publication in Physical Review Letters

Published
2019

5. A geometric distance measurement to the Galactic Center black hole with 0.3% uncertainty

Author

Idel Waisberg, Thibaut Paumard, Julien Woillez, Jason Dexter, Oliver Pfuhl, Stefan Gillessen, Thomas Henning, Senol Yazici, Matthew Horrobin, Stefan Hippler, Christian Straubmeier, Karine Perraut, Odele Straub, J.-B. Le Bouquin, Sebastian Rabien, Amiel Sternberg, F. Vincent, António Amorim, Laurent Jocou, Vincent Lapeyrere, Reinhard Genzel, V. Coudé du Foresto, Feng Gao, Xavier Haubois, Gilles Duvert, Ekkehard Wieprecht, Jean-Philippe Berger, Paulo J. V. Garcia, Maryam Habibi, Thomas Ott, A. Jiménez-Rosales, Ortwin Gerhard, S. von Fellenberg, Linda J. Tacconi, G. Rousset, Eric Gendron, Guy Perrin, Pierre Kervella, Frank Eisenhauer, G. Rodriguez Coira, R. Abuter, Felix Widmann, Pierre Léna, Eckhard Sturm, Silvia Scheithauer, N. M. Förster Schreiber, Erich Wiezorrek, Henri Bonnet, Andreas Eckart, M. Bauböck, Sylvestre Lacour, Yann Clénet, P. T. de Zeeuw, Wolfgang Brandner, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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]), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Galaxy: nucleus, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Galactic Center, black hole physics, FOS: Physical sciences, Astronomy and Astrophysics, Orbital eccentricity, Astrometry, Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Redshift, Black hole, Orbit, Interferometry, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, astrometry, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Gravitational redshift
Abstract

We present a 0.16% precise and 0.27% accurate determination of R0, the distance to the Galactic Center. Our measurement uses the star S2 on its 16-year orbit around the massive black hole Sgr A* that we followed astrometrically and spectroscopically for 27 years. Since 2017, we added near-infrared interferometry with the VLTI beam combiner GRAVITY, yielding a direct measurement of the separation vector between S2 and Sgr A* with an accuracy as good as 20 micro-arcsec in the best cases. S2 passed the pericenter of its highly eccentric orbit in May 2018, and we followed the passage with dense sampling throughout the year. Together with our spectroscopy, in the best cases with an error of 7 km/s, this yields a geometric distance estimate: R0 = 8178 +- 13(stat.) +- 22(sys.) pc. This work updates our previous publication in which we reported the first detection of the gravitational redshift in the S2 data. The redshift term is now detected with a significance level of 20 sigma with f_redshift = 1.04 +- 0.05., Comment: 9 pages, 7 figures, submitted to A&A

Published
2019
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6. Short life and abrupt death of PicSat, a small 3U CubeSat dreaming of exoplanet detection

Author

Guillaume Schworer, Mathias Nowak, Antoine Crouzier, Lester David, Vincent Lapeyrere, and Sylvestre Lacour

Subjects
010504 meteorology & atmospheric sciences, Payload, Computer science, FOS: Physical sciences, Astronomy, 01 natural sciences, Exoplanet, Starlight, 0103 physical sciences, Hill sphere, Beta Pictoris, Satellite, CubeSat, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Transit (satellite), 0105 earth and related environmental sciences
Abstract

PicSat was a three unit CubeSat (measuring 30 cm x 10 cm x 10 cm) which was developed to monitor the beta Pictoris system. The main science objective was the detection of a possible transit of the giant planet beta Pictoris b's Hill sphere. Secondary objectives included studying the circumstellar disk, and detecting exocomets in the visible band. The mission also had a technical objective: demonstrate our ability to inject starlight in a single mode fiber, on a small satellite platform. To answer all those objectives, a dedicated opto-mechanical payload was built, and integrated in a commercial 3U platform, along with a commercial ADCS (Attitude Determination and Control System). The satellite successfully reached Low Earth Orbit on the PSLV-C40 rocket, on January, 12, 2018. Unfortunately, on March, 20, 2018, after 10 weeks of operations, the satellite fell silent, and the mission came to an early end. Furthermore, due to a failure of the ADCS, the satellite never actually pointed toward its target star during the 10 weeks of operations. In this paper, we report on the PicSat mission development process, and on the reasons why it did not deliver any useful astronomical data., Comment: 11 pages, 11 figures

Published
2018

7. SAGE: using CubeSats for Gravitational Wave Detection

Author

Julien Woillez, Lester David, A. Kellerer, Sylvestre Lacour, Pierre Bourget, A. Le Tiec, Mathias Nowak, F. Vincent, Vincent Lapeyrere, O. Straub, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), 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 Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
geometry, interferometer, FOS: Physical sciences, geostationary, 01 natural sciences, 7. Clean energy, High Energy Physics - Experiment, thermal, High Energy Physics - Experiment (hep-ex), Acceleration, General Relativity and Quantum Cosmology, pressure, Optics, 0103 physical sciences, optical, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, effect: solar, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, orbit, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Spacecraft, business.industry, Gravitational wave, gravitational radiation, acceleration, Trajectory of a projectile, tracks, recombination, observatory, Orbit, Interferometry, Solar wind, gravitational waves, frequency, trajectory, cubesats, Geostationary orbit, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], nanosats
Abstract

SAGE (SagnAc interferometer for Gravitational wavE) is a fast track project for a space observatory based on multiple 12-U CubeSats in geostationary orbit. The objective of this project is to create a Sagnac interferometer with 73000 km circular arms. The geometry of the interferometer makes it especially sensitive to circularly polarized gravitational waves at frequency close to 1 Hz. The nature of the Sagnac measurement makes it almost insensitive to position error, allowing spacecrafts in ballistic trajectory. The light source and recombination units of the interferometer are based on compact fibered technologies, without the need of an optical bench. The main limitation would come from non-gravitational acceleration of the spacecraft. However, conditionally upon our ability to post-process the effect of solar wind, solar pressure and thermal expansion, we would detect gravitational waves with strains down to 10^-21 over a few days of observation., Comment: published in SPIE conference proceedings, 2018

Published
2018

8. GRAVITY chromatic imaging of η Car's core. Milliarcsecond resolution imaging of the wind-wind collision zone (Brγ, He I)

Author

S. Kellner, Pierre Kervella, Faustine Cantalloube, Johana Panduro, Magdalena Lippa, V. Coudé du Foresto, Y. Clénet, R. Abuter, G. Avila, Matteo Accardo, Konrad R. W. Tristram, Dan Popovic, Alejandra Rosales, A. Buron, R. Genzel, C. Deen, Laurent Jocou, Markus Schöller, T. Ott, H. Bonnet, P. Fédou, Frank Eisenhauer, R. van Boekel, Stefan Hippler, André Müller, Pierre Léna, Thibaut Moulin, Julien Woillez, L. Pallanca, Ekkehard Wieprecht, P.-O. Petrucci, N. Hubin, Leander Mehrgan, Sylvestre Lacour, Markus Wittkowski, Vincent Lapeyrere, Christian A. Hummel, M. Haug, Eckhard Sturm, Frederic Derie, Thanh Phan Duc, Sarah Kendrew, Burkhard Wolff, Mario Kiekebusch, Nicolas Blind, Andreas Kaufer, W. J. de Wit, Feng Gao, C. Collin, Silvia Scheithauer, L. Kern, Roderick Dembet, Matthew Horrobin, J.-U. Pott, Stefan Gillessen, Johann Kolb, Narsireddy Anugu, R.-R. Rohloff, M. Riquelme, J. Sanchez-Bermudez, Andreas Eckart, J. Moreno-Ventas, R. Brast, Z. Hubert, Isabelle Percheron, M. Mellein, F. Delplancke-Ströbele, M. Karl, Udo Neumann, Imke Wank, Rainer Lenzen, Odele Straub, Michael Esselborn, Armin Huber, J.-B. Le Bouquin, Ralf Klein, Juan-Luis Ramos, Erich Wiezorrek, Samuel Lévêque, K. Perraut, Frédéric Cassaing, C. E. Garcia Dabo, F. Müller, P. M. Plewa, Ewald Müller, N. Ventura, F. Chapron, Gerd Weigelt, M. Ebert, Martin Kulas, M. Wiest, Elodie Choquet, Luca Pasquini, A. Caratti o Garatti, A. Pflüger, T. de Zeeuw, Guy Perrin, Myriam Benisty, Yves Magnard, Joachim M. Bestenlehner, S. Oberti, António Amorim, Nicolas Schuhler, B. Lazareff, Paulo J. V. Garcia, Jason Dexter, Christian Straubmeier, Th. Henning, Jason Spyromilio, F. H. Vincent, A. Mérand, Senol Yazici, Felix Widmann, C. Rau, Pierre Bourget, R. J. García López, Xavier Haubois, Eric Gendron, Gérard Zins, G. Rousset, Andres J. Ramirez, Gilles Duvert, T. Paumard, Lieselotte Jochum, Idel Waisberg, F. Haussmann, O. Pfuhl, Sebastian Rabien, G. Rodríguez-Coira, Gerd Jakob, J. P. Berger, Wolfgang Brandner, D. Ziegler, and Marcos Suarez

Subjects
Physics, 010308 nuclear & particles physics, Binary number, Astronomy and Astrophysics, Astrophysics, Collision, 01 natural sciences, Galaxy, Wavelength, 13. Climate action, Space and Planetary Science, Angular diameter, 0103 physical sciences, Radiative transfer, Chromatic scale, 010303 astronomy & astrophysics, Cavity wall
Abstract

Context. η Car is one of the most intriguing luminous blue variables in the Galaxy. Observations and models of the X-ray, ultraviolet, optical, and infrared emission suggest a central binary in a highly eccentric orbit with a 5.54 yr period residing in its core. 2D and 3D radiative transfer and hydrodynamic simulations predict a primary with a dense and slow stellar wind that interacts with the faster and lower density wind of the secondary. The wind-wind collision scenario suggests that the secondary’s wind penetrates the primary’s wind creating a low-density cavity in it, with dense walls where the two winds interact. However, the morphology of the cavity and its physical properties are not yet fully constrained. Aims. We aim to trace the inner ∼5–50 au structure of η Car’s wind-wind interaction, as seen through Brγ and, for the first time, through the He I 2s-2p line. Methods. We have used spectro-interferometric observations with the K-band beam-combiner GRAVITY at the VLTI. The analyses of the data include (i) parametrical model-fitting to the interferometric observables, (ii) a CMFGEN model of the source’s spectrum, and (iii) interferometric image reconstruction. Results. Our geometrical modeling of the continuum data allows us to estimate its FWHM angular size close to 2 mas and an elongation ratio ϵ = 1.06 ± 0.05 over a PA = 130° ± 20°. Our CMFGEN modeling of the spectrum helped us to confirm that the role of the secondary should be taken into account to properly reproduce the observed Brγ and He I lines. Chromatic images across the Brγ line reveal a southeast arc-like feature, possibly associated to the hot post-shocked winds flowing along the cavity wall. The images of the He I 2s-2p line served to constrain the 20 mas (∼50 au) structure of the line-emitting region. The observed morphology of He I suggests that the secondary is responsible for the ionized material that produces the line profile. Both the Brγ and the He I 2s-2p maps are consistent with previous hydrodynamical models of the colliding wind scenario. Future dedicated simulations together with an extensive interferometric campaign are necessary to refine our constraints on the wind and stellar parameters of the binary, which finally will help us predict the evolutionary path of η Car.

Published
2018

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