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1. Pilot Study and Early Results of the Cosmic Filaments and Magnetism Survey with Nenufar: The Coma Cluster Field

Author: Etienne Bonnassieux, Evangelia Tremou, Julien N. Girard, Alan Loh, Valentina Vacca, Stéphane Corbel, Baptiste Cecconi, Jean-Mathias Grießmeier, Léon V. E. Koopmans, Michel Tagger, Gilles Theureau, and Philippe Zarka
Subjects: galaxy clusters, observational cosmology, radio interferometry, nenufar, Astronomy, QB1-991
Abstract: NenuFAR, the New Extension in Nancay Upgrading LOFAR, is currently in its early science phase. It is in this context that the Cosmic Filaments and Magnetism Pilot Survey is observing sources with the array as it is still under construction—with 57 (56 core, 1 distant) out of a total planned 102 (96 core, 6 distant) mini-arrays online at the time of observation—to get a first look at the low-frequency sky with NenuFAR. One of its targets is the Coma galaxy cluster: a well-known object, host of the prototype radio halo. It also hosts other features of scientific import, including a radio relic, along with a bridge of emission connecting it with the halo. It is thus a well-studied object.In this paper, we show the first confirmed NenuFAR detection of the radio halo and radio relic of the Coma cluster at 34.4 MHz, with associated intrinsic flux density estimates: we find an integrated flux value of 106.3 ± 3.5 Jy for the radio halo, and 102.0 ± 7.4 Jy for the radio relic. These are upper bound values, as they do not include point-source subtraction. We also give an explanation of the technical difficulties encountered in reducing the data, along with steps taken to resolve them. This will be helpful for other scientific projects which will aim to make use of standalone NenuFAR imaging observations in the future.
Published: 2021
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2. Pilot Study and Early Results of the Cosmic Filaments and Magnetism Survey with Nenufar: The Coma Cluster Field

Author: Evangelia Tremou, Alan Loh, Michel Tagger, Baptiste Cecconi, Gilles Theureau, V. Vacca, Jean-Mathias Griessmeier, Julien N. Girard, Stephane Corbel, Leon Koopmans, Bonnassieux Etienne, Philippe Zarka, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), NenuFAR has been supported by personnel and funding from: Station de Radioastronomie de Nançay, CNRS-INSU, Observatoire de Paris-PSL, Université d’Orléans, Observatoire des Sciences de l’Univers en Région Centre, Région Centre-Val de Loire, DIM-ACAV and DIM-ACAV+ of Région Île-de-France, Agence Nationale de la Recherche, European Project: 714245,DRANOEL - H2020-EU.1.1., Kapteyn Astronomical Institute, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), and NenuFAR has been supported by personnel and funding from: Station de Radioastronomie deNançay, CNRS-INSU, Observatoire de Paris-PSL, Université d’Orléans, Observatoire des Sciences de l’Univers en Région Centre, Région Centre-Val de Loire, DIM-ACAV and DIM-ACAV+ of Région Île-de-France, Agence Nationale de la Recherche
Subjects: 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Astronomy, FOS: Physical sciences, Context (language use), QB1-991, Astrophysics, 01 natural sciences, observational cosmology, 0103 physical sciences, Coma Cluster, galaxy clusters, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Galaxy cluster, 0105 earth and related environmental sciences, media_common, Physics, COSMIC cancer database, radio interferometry, Astronomy and Astrophysics, LOFAR, Astrophysics - Astrophysics of Galaxies, nenufar, Radio halo, Sky, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), Halo, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: NenuFAR, the New Extension in Nancay Upgrading LOFAR, is currently in its early science phase. It is in this context that the Cosmic Filaments and Magnetism Pilot Survey is observing sources with the array as it is still under construction - with 57 (56 core, 1 distant) out of a total planned 102 (96 core, 6 distant) mini-arrays online at the time of observation - to get a first look at the low-frequency sky with NenuFAR. One of its targets is the Coma galaxy cluster: a well-known object, host of the prototype radio halo. It also hosts other features of scientific import, including a radio relic, along with a bridge of emission connecting it with the halo. It is thus a well-studied object. In this paper, we show the first confirmed NenuFAR detection of the radio halo and radio relic of the Coma cluster at 34.4 MHz, with associated intrinsic flux density estimates: we find an integrated flux value of 106.3 +- 3.5 Jy for the radio halo, and 102.0 +- 7.4 Jy for the radio relic. These are upper bound values, as they do not include point-source subtraction. We also give an explanation of the technical difficulties encountered in reducing the data, along with steps taken to resolve them. This will be helpful for other scientific projects which will aim to make use of standalone NenuFAR imaging observations in the future., Comment: 14 pages, 4 figures, special issue of the Galaxies journal
Published: 2021

3. Observations of shock propagation through turbulent plasma in the solar corona

Author: A. Loh, Carine Briand, Julien N. Girard, Baptiste Cecconi, Gilles Theureau, Caterina Tiburzi, Nicole Vilmer, Sophie Masson, Stephane Corbel, Hamish A. S. Reid, K. Sasikumar Raja, Philippe Zarka, Jean-Mathias Grießmeier, V. V. Dorovskyy, Eoin P. Carley, Michel Tagger, Pietro Zucca, 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), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)
Subjects: Physics, Turbulent plasma, Shock propagation, 010504 meteorology & atmospheric sciences, particle acceleration, Astrophysics::High Energy Astrophysical Phenomena, turbulence, FOS: Physical sciences, Astronomy and Astrophysics, Mechanics, 01 natural sciences, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Physics::Space Physics, 010303 astronomy & astrophysics, Shocks, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences
Abstract: Eruptive activity in the solar corona can often lead to the propagation of shock waves. In the radio domain the primary signature of such shocks are type II radio bursts, observed in dynamic spectra as bands of emission slowly drifting towards lower frequencies over time. These radio bursts can sometimes have inhomogeneous and fragmented fine structure, but the cause of this fine structure is currently unclear. Here we observe a type II radio burst on 2019-March-20th using the New Extension in Nan\c{c}ay Upgrading LOFAR (NenuFAR), a radio interferometer observing between 10-85 MHz. We show that the distribution of size-scales of density perturbations associated with the type II fine structure follows a power law with a spectral index in the range of $\alpha=-1.7$ to -2.0, which closely matches the value of $-5/3$ expected of fully developed turbulence. We determine this turbulence to be upstream of the shock, in background coronal plasma at a heliocentric distance of $\sim$2 R$_{\odot}$. The observed inertial size-scales of the turbulent density inhomogeneities range from $\sim$62 Mm to $\sim$209 km. This shows that type II fine structure and fragmentation can be due to shock propagation through an inhomogeneous and turbulent coronal plasma, and we discuss the implications of this on electron acceleration in the coronal shock.
Published: 2021

4. Pulsars with NenuFAR: backend and pipelines

Author: Cyril Tasse, A. Possenti, Serge Yerin, Siyuan Chen, L. Bondonneau, C. Viou, M. Serylak, G. Shaifullah, Richard Dallier, J. W. McKee, Z. Wu, Julien N. Girard, Baptiste Cecconi, J.-M. Grießmeier, V. I. Kondratiev, M. Tagger, L. Guillemot, M. Brionne, Maura Pilia, R. A. Main, A. Loh, Ismaël Cognard, P. Zarka, Joris P. W. Verbiest, Caterina Tiburzi, Lilian Martin, Carine Briand, Stephane Corbel, A. V. Bilous, G. Theureau, Olaf Wucknitz, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-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), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), 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), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Netherlands Institute for Radio Astronomy (ASTRON), Max-Planck-Institut für Radioastronomie (MPIFR), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Universität Bielefeld = Bielefeld University, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Rhodes University, Grahamstown, 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), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Bondonneau, L, Griessmeier, J, Theureau, G, Cognard, I, Brionne, M, Kondratiev, V, Bilous, A, Mckee, J, Zarka, P, Viou, C, Guillemot, L, Chen, S, Main, R, Pilia, M, Possenti, A, Serylak, M, Shaifullah, G, Tiburzi, C, Verbiest, J, Wu, Z, Wucknitz, O, Yerin, S, Briand, C, Cecconi, B, Corbel, S, Dallier, R, Girard, J, Loh, A, Martin, L, Tagger, M, Tasse, C, Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: Physics - Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, 4/3, 01 natural sciences, frequency: high, Radio telescope, High Energy Physics - Phenomenology (hep-ph), Pulsar, Millisecond pulsar, Observatory, pulsars: general, 0103 physical sciences, site, Instrumentation (computer programming), structure, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), pulsar, Physics, radio wave, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Crab Pulsar, Astrophysics::Instrumentation and Methods for Astrophysics, resolution, Astronomy and Astrophysics, LOFAR, Instrumentation and Detectors (physics.ins-det), sensitivity, coherence, observatory, High Energy Physics - Phenomenology, frequency: low, Space and Planetary Science, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], dispersion, methods: observational, Astrophysics - Instrumentation and Methods for Astrophysics, performance, Radio wave
Abstract: NenuFAR (New extension in Nan\c{c}ay upgrading LoFAR) is a new radio telescope developed and built on the site of the Nan\c{c}ay Radio Observatory. It is designed to observe the largely unexplored frequency window from 10 to 85\,MHz, offering a high sensitivity across its full bandwidth. NenuFAR has started its "early science" operation in July 2019, with 58\% of its final collecting area being available. Pulsars are one of the major topics for the scientific exploitation of this frequency range and represent an important challenge in terms of instrumentation. Designing instrumentation at these frequencies is complicated by the need to compensate for the effects of both the interstellar medium and the ionosphere on the observed signal. Our real-time pipeline LUPPI (Low frequency Ultimate Pulsar Processing Instrumentation) is able to cope with a high data rate and to provide real-time coherent de-dispersion down to the lowest frequencies reached by NenuFAR (10\,MHz). The full backend functionality is described, as well as the main pulsar observing modes (folded, single-pulse, waveform, and dynamic spectrum). This instrumentation allowed us to detect 172 pulsars in our first targeted search below 85\,MHz, including 10 millisecond pulsars (6 of which detected for the first time below 100 MHz). We also present some of the "early science" results of NenuFAR on pulsars: a high frequency resolution mapping of PSR B1919$+$21's emission profile and a detailed observation of single-pulse sub-structures from PSR~B0809$+$74 down to 16\,MHz, the high rate of giant-pulse emission from the Crab pulsar detected at 68.7\,MHz (43 events/min), and the illustration of the very good timing performance of the instrumentation, allowing us to study dispersion measure variations in great detail., Comment: 13 pages, 14 figures, submitted to A&A
Published: 2020

5. Phased Subarray of the Low-Frequency Radio Telescope GURT as a Standalone Instrument for Radio Astronomy Studies

Author: A. Coffre, Peter L. Tokarsky, D. V. Mukha, A. I. Myasoyed, I. P. Kravtsov, A. D. Khristenko, V. V. Zakharenko, G. Kvasov, A. S. Belov, Y. Vasylkivskyi, Aleksander Stanislavsky, V. Bortsov, L. Denis, S. V. Stepkin, V. A. Shepelev, M. V. Shevchuk, I. M. Bubnov, Julien N. Girard, S. N. Yerin, P. Zarka, Valentin Melnik, M. A. Sydorchuk, V. Kharlanova, D. Charier, O. M. Ulyanov, V. Lisachenko, M. M. Kalinichenko, A. Reznichenko, Mykhaylo Panchenko, V. V. Dorovskyy, Helmut O. Rucker, Alexandr A. Konovalenko, A. I. Shevtsova, 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), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Beamforming, Computer science, business.industry, Antenna aperture, Electrical engineering, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Low frequency, Directivity, Radio telescope, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Antenna (radio), business, Digital signal processing, Radio astronomy
Abstract: International audience; Cutting edge astrophysical studies require more and more observing time at low-frequency radio telescopes, which is limited and quite expensive. Modern digital signal processing systems still unable to provide affordable computational and storage resources to allow simultaneous beamforming in a wide frequency range for multiple studies. Low-frequency radio telescopes of a new generation are very flexible and could be split into subarrays or groups of subarrays for some studies which do not require large antenna effective area and high directivity. In this paper we make a survey of astrophysical studies in the frequency range 8-80 MHz using a rather small part of the low-frequency radio telescope GURT - the subarray of 25 active antennas.
Published: 2020

6. Exploration of the Potential of the Radio-Detection Technique for the Detection of High-Energy Gamma Rays

Author: Julien N. Girard, Jean-Mathias Grießmeier, Stephane Corbel, Alan Loh, Cedric Dumez-Viou, Laurent Denis, Antony Escudie, Richard Dallier, M. Pandey-Pommier, Philippe Zarka, L. Bondonneau, Didier Charrier, Daniel García-Fernández, Lilian Martin, A. Coffre, Leon Koopmans, Benoît Revenu, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), 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), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], 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), CODALEMA, Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Physics, High energy, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Direction of arrival, Cosmic ray, 7. Clean energy, Radio spectrum, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Radio telescope, Observatory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Radio detection
Abstract: International audience; The radio detection of atmospheric particle showers initiated by ultra-high energy cosmic rays is today a proven technique that allows to reconstruct their properties (direction of arrival, energy, nature). Among the precursors of this method, the CODALEMA experiment installed at the Nançay radio-astronomy Observatory has contributed to several major technological innovations relevant for the radio detection technique (autonomous triggering, hybrid reconstruction, very wide frequency bands) and its high-performance antennas are also used on the NenuFAR radio telescope in Nançay. We propose to exploit the unique environment of the Nan\c cay Observatory through the CODALEMA experiment and the NenuFAR radio-telescope to explore the possibilities of radio-detection of atmospheric showers initiated by very high energy photons. The central idea is to phase a large set of antennas (several tens) in the direction of known sources emitting gamma (catalogs H.E.S.S., MAGIC, VERITAS, Fermi-LAT ...) to significantly increase the sensitivity of detection and to use the triggering capabilities on ultra fast transients controlled within the framework of CODALEMA. This would make it possible to observe the sources with a useful cycle close to 100 %. We present here the intended instrumental scheme as well as the expected signal level and some first results obtained on the observation of cosmic ray air showers with NenuFAR.
Published: 2019

7. Detecting exoplanets with FAST?

Author: P. Zarka, Jean-Mathias Grießmeier, T. Joseph W. Lazio, Sebastien Hess, Gregg Hallinan, Laurent Lamy, Di Li, Julien N. Girard, 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), National Astronomical Observatory, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, ONERA - The French Aerospace Lab [Toulouse], ONERA, California Institute of Technology (CALTECH), 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 de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: radio continuum: planetary systems, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, telescopes (radio), Physical information, 0103 physical sciences, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010308 nuclear & particles physics, Astronomy and Astrophysics, radiation mechanisms: non-thermal, plasmas, Exoplanet, planets and satellites: magnetic fields, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, methods: observational, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: We briefly review the various proposed scenarios that may lead to nonthermal radio emissions from exoplanetary systems (planetary magnetospheres, magnetosphere-ionosphere and magnetosphere-satellite coupling, and star-planet interactions), and the physical information that can be drawn from their detection. The latter scenario is especially favorable to the production of radio emission above 70\,MHz. We summarize the results of past and recent radio searches, and then discuss FAST characteristics and observation strategy, including synergies. We emphasize the importance of polarization measurements and a high duty-cycle for the very weak targets that radio-exoplanets prove to be., 6 pages, 3 figures, published in the mini-volume on FAST science potentials in the journal Research in Astronomy and Astrophysics
Published: 2019

8. The low-frequency radiotelescope NenuFAR

Author: A. Loh, Jean-Mathias Griessmeier, Philippe Zarka, Michel Tagger, Julien N. Girard, Cedric Dumez-Viou, A. Coffre, L. Denis, 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), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Département de Mathématiques [Evry], Université d'Évry-Val-d'Essonne (UEVE), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), ANR-17-CE31-0013,NRI,Un imageur radio basses fréquences pour NenuFAR(2017), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), and PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: Physics, 010308 nuclear & particles physics, Astronomy, LOFAR, 01 natural sciences, 7. Clean energy, Galaxy, Exoplanet, Electronic mail, Stars, Pulsar, [SDU]Sciences of the Universe [physics], Stellar physics, 0103 physical sciences, Angular resolution, 010303 astronomy & astrophysics
Abstract: International audience; NenuFAR (New extension in Nançay upgrading LOFAR), is a low-frequency SKA pathfinder presently in construction and commissioning in Nançay (France) [1], [2]. NenuFAR consists of 102 mini-arrays (MA) of 19 dual polarization antennas each. 96 MA cover densely a disk (core) of 400m in diameter, and 6 MA are located at distances up to ~3 km. NenuFAR will cover the range 10-85 MHz, that encompasses the low-frequency range of LOFAR ([3] 0-80 MHz nominal, that can be extended to 10-85 MHz), and be three instruments in one: (i)the core, connected to the receivers of the French LOFAR (FR606) station, will form a giant LOFAR station that can replace the LOFAR FR606 LBA field and be used as part of LOFAR; this LOFAR Super Station (LSS) will improve the sensitivity of long baselines by over one order of magnitude and thus the quality of high angular resolution (sub-arcsecond) imaging at low frequencies with LOFAR. (ii)the core will simultaneously be a standalone compact beamformer providing high instantaneous sensitivity, that will allows us to search efficiently for weak unresolved sources such as pulsars, exoplanets, stars ...A dedicated pulsar/time/frequency backend is in development, and the possibility to connect a SETI receiver that will analyze all NenuFAR data in piggyback (commensal) mode is under study. (iii)finally, thanks to the addition of a GPU-based correlator, NenuFAR will also (and simultaneously) be a standalone imager that can be used in two modes: a fast (1 sec) coarse resolution (1°) mode, using the 96 MA of the core only, and a slow (6-8 hours) medium resolution (~8') mode using all the 102 MA, core + distant; this mode will enable imaging studies in cosmology (search for the dark ages / cosmic dawn signal), planetary and stellar physics (exoplanets, stars and their plasma interactions), and the study of galaxies, clusters and haloes.
Published: 2018

9. NOIRE study report: Towards a low frequency radio interferometer in space

Author: Albert-Jan Boonstra, Mickael Bruno, Mark J. Bentum, Patrick Gélard, Alain Lamy, Julien N. Girard, Baptiste Cecconi, Quentin Nénon, Michel Delpech, Jean-Mathias Grießmeier, Moustapha Dekkali, Carine Briand, David Valat, Boris Segret, Martin Bucher, Andre Laurens, 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), CEA Sorbonne Paris Cité, Centre National d'Études Spatiales [Toulouse] (CNES), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Netherlands Institute for Radio Astronomy (ASTRON), Eindhoven Technical University, Université Paris Diderot, Sorbonne Paris Cité, Paris, France, Université Paris Diderot - Paris 7 (UPD7), PRES Université de Toulouse-ONERA, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Electromagnetics, Center for Wireless Technology Eindhoven, EM for Radio Science Lab, 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), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Technische Universiteit Eindhoven (TU/e)
Subjects: [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Computer science, business.industry, Electrical engineering, Electromagnetic compatibility, FOS: Physical sciences, Magnetosphere, Lagrangian point, Ranging, Orbit of the Moon, 7. Clean energy, 01 natural sciences, Clock synchronization, Interferometry, Observatory, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Astronomical interferometer, 010306 general physics, business, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics
Abstract: Ground based low frequency radio interferometers have been developed in the last decade and are providing the scientific community with high quality observations. Conversely, current radioastronomy instruments in space have a poor angular resolution with single point observation systems. Improving the observation capabilities of the low frequency range (a few kHz to 100 MHz) requires to go to space and to set up a space based network of antenna that can be used as an interferometer. We present the outcome of the NOIRE (Nanosatellites pour un Observatoire Interf\'erom\'etrique Radio dans l'Espace / Nanosatellites for a Radio Interferometer Observatory in Space) study which assessed, with help of CNES PASO (Architecture Platform for Orbital Systems is CNES' cross-disciplinary team in charge of early mission and concept studies), the feasibility of a swarm of nanosatellites dedicated to a low frequency radio observatory. With such a platform, space system engineering and instrument development must be studied as a whole: each node is a sensor and all sensors must be used together to obtain a measurement. The study was conducted on the following topics: system principle and concept (swarm, node homogeneity); Space and time management (ranging, clock synchronization); Orbitography (Moon orbit, Lagrange point options); Telecommunication (between nodes and with ground) and networking; Measurements and processing; Propulsion; Power; Electromagnetic compatibility. No strong show-stopper was identified during the preliminary study, although the concept is not yet ready. Several further studies and milestones are identified. The NOIRE team will collaborate with international teams to try and build this next generation of space systems., Comment: Submitted to IEEEAeroconf 2018 proceedings
Published: 2018

10. The SHARDDS survey: First resolved image of the HD 114082 debris disk in the Lower Centaurus Crux with SPHERE

Author: Dimitri Mawet, Mark C. Wyatt, Steve Ertel, Hiroshi Kobayashii, Anne-Marie Lagrange, Christophe Pinte, Julien N. Girard, Anthony Boccaletti, David Mouillet, Carlos del Burgo, William R. F. Dent, Laurent Pueyo, Carlos Gomez Gonzalez, Luca Matrà, Julien Milli, Elodie Choquet, Grant M. Kennedy, Jean-Charles Augereau, Olivier Absil, Zahed Wahhaj, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Steward Observatory, University of Arizona, 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), Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), Laboratoire Franco-Chilien d'Astronomie (LFCA), Universidad de Concepción [Chile]-Pontificia Universidad Católica de Chile (UC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Universidad de Chile, 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]), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Space Telescope Science Institute (STSci), 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), 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), Kennedy, Grant [0000-0001-6831-7547], Matr<U+FFFD>, Luca [0000-0003-4705-3188], Wyatt, Mark [0000-0001-9064-5598], Apollo - University of Cambridge Repository, and Universidad de Chile = University of Chile [Santiago] (UCHILE)-Pontificia Universidad Católica de Chile (UC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Universidad de Concepción - University of Concepcion [Chile]
Subjects: 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Luminosity, Angular diameter, Planet, 0103 physical sciences, Beta Pictoris, Astrophysics::Solar and Stellar Astrophysics, planetary systems, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], Debris disk, techniques: high angular resolution, Astronomy and Astrophysics, Radius, Position angle, Radiation pressure, Space and Planetary Science, stars: individual: HD 114082, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the first resolved image of the debris disk around the 16+/-8 Myr old star, HD 114082. The observation was made in the H-band using the SPHERE instrument. The star is at a distance of 92+/-6 pc in the Lower Centaurus Crux association. Using a Markov Chain Monte Carlo analysis, we determined that the debris is likely in the form of a dust ring with an inner edge of 27.7+2.8/-3.5 au, position angle -74+0.5/-1.5 deg, and an inclination with respect to the line of sight of 6.7+3.8/-0.4 deg. The disk imaged in scattered light has a surface density declining with radius like ~r^(-4), steeper than expected for grain blowout by radiation pressure. We find only marginal evidence (2 sigma) of eccentricity, and rule out planets more massive than 1.0 Mjup orbiting within 1 au of the ring's inner edge, since such a planet would have disrupted the disk. The disk has roughly the same fractional disk luminosity (Ldisk/L*=3.3x10^(-3)) as HR4796A and Beta Pictoris, however it was not detected by previous instrument facilities most likely because of its small angular size (radius~0.4"), low albedo (~0.2) and low scattering efficiency far from the star due to high scattering anisotropy. With the arrival of extreme adaptive optics systems like SPHERE and GPI, the morphology of smaller, fainter and more distant debris disks are being revealed, providing clues to planet-disk interactions in young protoplanetary systems., Comment: 8 pages, 4 figures
Published: 2016

11. Astrophysical Studies with Small Low-Frequency Radio Telescopes of New Generation

Author: D. V. Mukha, Serge Yerin, A. A. Konovalenko, M. M. Kalinichenko, O. M. Ulyanov, Peter L. Tokarsky, V. Bortsov, S. V. Stepkin, V. L. Koliadin, O. M. Reznichenko, Mykhaylo Panchenko, I. Y. Vasylieva, G. Kvasov, V. Lisachenko, A. I. Brazhenko, A. O. Skoryk, V. M. Melnik, A. O. Gridin, Loïc Denis, A. I. Shevtsova, I. M. Bubnov, K. Mylostna, Julien N. Girard, O. D. Khristenko, Aleksander Stanislavsky, M. A. Sidorchuk, H. O. Rucker, V. V. Dorovskyy, V. V. Zakharenko, P. Zarka, G. Litvinenko, Institute of Radio Astronomy of NASU [Kharkiv] (IRA), National Academy of Sciences of Ukraine (NASU), 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), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Main Astronomical Observatory of NAS of Ukraine (MAO), Observatoire des Sciences de l'Univers en région Centre (OSUC), and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, decameter and meter radio waves, 010504 meteorology & atmospheric sciences, Physics and Astronomy (miscellaneous), astrophysics, smallsized radio telescope, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], lcsh:Astronomy, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Astrophysics, Low frequency, 01 natural sciences, Radio telescope, lcsh:QB1-991, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Very-long-baseline interferometry, Electrical and Electronic Engineering, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Purpose: define and theoretically substantiate the range of astrophysical problems that may be efficiently solved using small antenna arrays. Design/methodology/approach: Observation parameters and configurations of a set of small antenna arrays included in the future Giant Ukrainian radio telescope, have been derived based on the theoretical analysis and scientific results obtained by UTR-2 and URAN radio telescopes. Results: We have proved that a wide scope of problems can be efficiently solved by small low-frequency antenna arrays, ranging from Solar studies to the search for cosmological effects associated with neutral hydrogen spectral line in the early Universe at high red shifts. For each study program, we have calculated the desired observation parameters (integration time, time and frequency resolutions), indicated the required antenna configurations and operating modes (interferometric or additive). Conclusions: We have shown that at the construction stage of the Giant Ukrainian radio telescope and gradual commissioning of its new sections, we can solve a number of important astrophysical problems. As the new sections are being added, the observation techniques and data processing methods will constantly be improving.
Published: 2016

12. The modern radio astronomy network in Ukraine: UTR-2, URAN and GURT

Author: I. Y. Vasylieva, Valentin Melnik, A. P. Reznik, V. Bovkun, E. R. Rudavin, Julien N. Girard, Helmut O. Rucker, O. Lytvinenko, A. Kravtsov, A. Lozinsky, K. Mylostna, Dmytro M. Vavriv, A. A. Gridin, Jean-Mathias Grieβmeier, N. V. Shevchuk, A. I. Shevtsova, V. V. Vinogradov, V. V. Dorovskyy, Aleksander Stanislavsky, Valery V. Shevchenko, A. Reznichenko, G. Kvasov, A. Kuzin, Peter L. Tokarsky, Y. Volvach, I. P. Kravtsov, S. N. Yerin, M. A. Sidorchuk, A. D. Khristenko, I. N. Bubnov, D. V. Mukha, Michel Tagger, Vladimir B. Ryabov, M. R. Olyak, M. S. Plakhov, V. V. Zakharenko, Georg Fischer, A. Shevchenko, Carine Briand, A. Coffre, A. O. Skoryk, V. Bortsov, S. V. Stepkin, A. Antonov, O. Pylaev, V. A. Shepelev, A. P. Miroshnichenko, R. V. Vashchishin, Alain Lecacheux, O. Ivantyshin, Loïc Denis, V. F. Kulishenko, A. I. Brazhenko, O. M. Ulyanov, V. Lisachenko, P. Zarka, A. A. Konovalenko, A. S. Belov, E. Bulakh, L. G. Sodin, Mykhaylo Panchenko, Didier Charrier, A. Vasilyev, N. Vasilenko, N. N. Kalinichenko, V. Koshovyy, V. L. Koliadin, R. Kozhin, I. Zhouk, A. A. Koval, G. Mann, G. Litvinenko, Institute of Radio Astronomy of NASU [Kharkiv] (IRA), National Academy of Sciences of Ukraine (NASU), 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), Future University-Hakodate, Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Max-Planck-Gesellschaft, Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches Linguistiques sur l'Asie Orientale (CRLAO), École des hautes études en sciences sociales (EHESS)-Institut National des Langues et Civilisations Orientales (Inalco)-Centre National de la Recherche Scientifique (CNRS), Physical and Computing Mechanics Department, Physical and Computing Mechanics Department (TSU), Tomsk State University [Tomsk]-Tomsk State University [Tomsk], Main Astronomical Observatory of NAS of Ukraine (MAO), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Ingénierie des Matériaux Polymères (IMP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Hubert Curien [Saint Etienne] (LHC), Institut d'Optique Graduate School (IOGS)-Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), University of Leeds, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, 010504 meteorology & atmospheric sciences, Bandwidth (signal processing), Antenna aperture, Radio telescope, Astronomy, Astronomy and Astrophysics, LOFAR, 01 natural sciences, 7. Clean energy, Antenna array, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Space research, 0103 physical sciences, Very-long-baseline interferometry, Antenna arrays, Radio astronomy, Decametre, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing
Abstract: International audience; The current status of the large decameter radio telescope UTR-2 (Ukrainian T-shaped Radio telescope) together with its VLBI system called URAN is described in detail. By modernization of these instruments through implementation of novel versatile analog and digital devices as well as new observation techniques, the observational capabilities of UTR-2 have been substantially enhanced. The total effective area of UTR-2 and URAN arrays reaches 200 000 m2, with 24 MHz observational bandwidth (within the 8-32 MHz frequency range), spectral and temporal resolutions down to 4 kHz and 0.5 msec in dynamic spectrum mode or virtually unlimited in waveform mode. Depending on the spectral and temporal resolutions and confusion effects, the sensitivity of UTR-2 varies from a few Jy to a few mJy, and the angular resolution ranges from ~ 30 arcminutes (with a single antenna array) to a few arcseconds (in VLBI mode). In the framework of national and international research projects conducted in recent years, many new results on Solar system objects, the Galaxy and Metagalaxy have been obtained. In order to extend the observation frequency range to 8-80 MHz and enlarge the dimensions of the UTR-2 array, a new instrument - GURT (Giant Ukrainian Radio Telescope) - is now under construction. The radio telescope systems described herein can be used in synergy with other existing low-frequency arrays such as LOFAR, LWA, NenuFAR, as well as provide ground-based support for space-based instruments.
Published: 2016

13. Imaging Jupiter's radiation belts down to 127 MHz with LOFAR

Author: Gianni Bernardi, Jörg R. Hörandel, A. G. Polatidis, Ashish Asgekar, A. Nelles, Angélica Sicard, H. Munk, R. J. van Weeren, Jason W. T. Hessels, D. McKay-Bukowski, I. de Pater, Matthias Hoeft, Oleg Smirnov, A. W. Gunst, Frank Breitling, Arthur Corstanje, Sebastien Hess, Quentin Nénon, Mark J. Bentum, J. van Leeuwen, R. C. Vermeulen, M. Loose, P. Zarka, H. J. A. Röttgering, P. Maat, M. J. Norden, M. Tagger, J. Moldón, F. de Gasperin, S. Bourdarie, Rene P. Breton, Annalisa Bonafede, John D. Swinbank, I. van Bemmel, Stephane Corbel, Martin Bell, V. I. Kondratiev, M. Pandey-Pommier, M. Iacobelli, James M. Anderson, Roberto Pizzo, Marcus Brüggen, Satyendra Thoudam, M. C. Toribio, Gerard H. Kuper, Antonia Rowlinson, Jochen Eislöffel, S. Duscha, Rebecca McFadden, M. A. Garrett, Daniel Santos-Costa, Julien N. Girard, Matthias Steinmetz, B. Ciardi, O. Wucknitz, J.-M. Grießmeier, M. Kuniyoshi, Ralph A. M. J. Wijers, Wilfred Frieswijk, Heino Falcke, C. Tasse, W. N. Brouw, S. Markov, Emanuela Orrú, H. Paas, Adam Deller, W. Reich, Dominik J. Schwarz, J. W. Broderick, E. Juette, G. Mann, Philip Best, C. Vocks, E. de Geus, Girard, J.N., Zarka, P., Tasse, C., Hess, S., De Pater, I., Santos-Costa, D., Nenon, Q., Sicard, A., Bourdarie, S., Anderson, J., Asgekar, A., Bell, M.E., Van Bemmel, I., Bentum, M.J., Bernardi, G., Best, P., Bonafede, A., Breitling, F., Breton, R.P., Broderick, J.W., Brouw, W.N., Brüggen, M., Ciardi, B., Corbel, S., Corstanje, A., De Gasperin, F., De Geus, E., Deller, A., Duscha, S., Eislöffel, J., Falcke, H., Frieswijk, W., Garrett, M.A., Grießmeier, J., Gunst, A.W., Hessels, J.W.T., Hoeft, M., Hörandel, J., Iacobelli, M., Juette, E., Kondratiev, V.I., Kuniyoshi, M., Kuper, G., Van Leeuwen, J., Loose, M., Maat, P., Mann, G., Markoff, S., McFadden, R., McKay-Bukowski, D., Moldon, J., Munk, H., Nelles, A., Norden, M.J., Orru, E., Paas, H., Pandey-Pommier, M., Pizzo, R., Polatidis, A.G., Reich, W., Röttgering, H., Rowlinson, A., Schwarz, D., Smirnov, O., Steinmetz, M., Swinbank, J., Tagger, M., Thoudam, S., Toribio, M.C., Vermeulen, R., Vocks, C., Van Weeren, R.J., Wijers, R.A.M.J., Wucknitz, O., Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, ONERA - The French Aerospace Lab [Toulouse], ONERA, Netherlands Institute for Radio Astronomy (ASTRON), University of Southampton, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Royal Observatory Edinburgh (ROE), University of Edinburgh, Jacobs University [Bremen], Leibniz-Institut für Astrophysik Potsdam (AIP), Jodrell Bank Centre for Astrophysics (JBCA), University of Manchester [Manchester], Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Radboud University [Nijmegen], Hamburger Sternwarte/Hamburg Observatory, Universität Hamburg (UHH), Thüringer Landessternwarte Tautenburg (TLS), Leiden Observatory [Leiden], Universiteit Leiden, Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Department of Pure Mathematics and Mathematical Statistics (DPMMS), Faculty of mathematics Centre for Mathematical Sciences [Cambridge] (CMS), University of Cambridge [UK] (CAM)-University of Cambridge [UK] (CAM), Ruhr-Universität Bochum [Bochum], Max-Planck-Institut für Radioastronomie (MPIFR), University of Oulu, University of Groningen [Groningen], 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), CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Universität Bielefeld, Rhodes University, Grahamstown, Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH / Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures (DSMZ), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, ANR-11-IDEX-0005,USPC,Université Sorbonne Paris Cité(2011), European Project: 228261,EC:FP7:ERC,ERC-2008-AdG,SPARSEASTRO(2009), ITA, GBR, FRA, DEU, NLD, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Radboud university [Nijmegen], Universiteit Leiden [Leiden], Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), 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), Harvard University [Cambridge]-Smithsonian Institution, 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), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Jodrell Bank Centre for Astrophysics, Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), DPMMS/CMS, University of Cambridge [UK] (CAM), ANR-11-IDEX-0005-02/10-LABX-0023,UnivEarthS,Earth - Planets - Universe: observation, modeling, transfer(2011), Astronomy, High Energy Astrophys. & Astropart. Phys (API, FNWI), and Faculty of Science
Subjects: radio continuum: planetary systems, Brightness, 010504 meteorology & atmospheric sciences, radio continuum: planetary, EWI-27447, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Magnetosphere, FOS: Physical sciences, Astrophysics, Electron, METIS-321662, 7. Clean energy, 01 natural sciences, Jupiter, symbols.namesake, 0103 physical sciences, Emission spectrum, IR-103183, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Radio continuum: planetary system, Planets and satellites: magnetic field, Astronomy and Astrophysics, LOFAR, Astronomy and Astrophysic, planets and satellites: magnetic fields, Spectral flux density, 13. Climate action, Space and Planetary Science, Van Allen radiation belt, Techniques: interferometric, symbols, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, systems, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. Observing Jupiter's synchrotron emission from the Earth remains today the sole method to scrutinize the distribution and dynamical behavior of the ultra energetic electrons magnetically trapped around the planet (because in-situ particle data are limited in the inner magnetosphere). Aims. We perform the first resolved and low-frequency imaging of the synchrotron emission with LOFAR at 127 MHz. The radiation comes from low energy electrons (~1-30 MeV) which map a broad region of Jupiter's inner magnetosphere. Methods (see article for complete abstract) Results. The first resolved images of Jupiter's radiation belts at 127-172 MHz are obtained along with total integrated flux densities. They are compared with previous observations at higher frequencies and show a larger extent of the synchrotron emission source (>=4 $R_J$). The asymmetry and the dynamic of east-west emission peaks are measured and the presence of a hot spot at lambda_III=230 {\deg} $\pm$ 25 {\deg}. Spectral flux density measurements are on the low side of previous (unresolved) ones, suggesting a low-frequency turnover and/or time variations of the emission spectrum. Conclusions. LOFAR is a powerful and flexible planetary imager. The observations at 127 MHz depict an extended emission up to ~4-5 planetary radii. The similarities with high frequency results reinforce the conclusion that: i) the magnetic field morphology primarily shapes the brightness distribution of the emission and ii) the radiating electrons are likely radially and latitudinally distributed inside about 2 $R_J$. Nonetheless, the larger extent of the brightness combined with the overall lower flux density, yields new information on Jupiter's electron distribution, that may shed light on the origin and mode of transport of these particles., Comment: 10 pages, 12 figures, accepted for publication in A&A (27/11/2015) - abstract edited because of limited characters
Published: 2015

14. NenuFAR: Instrument description and science case

Author: Sylvain Azarian, A. Bosma, Chiara Ferrari, A. Petiteau, Loïc Denis, M. Pandey-Pommier, Luitje Koopmans, Remy Boyer, M. Arnaud, C. Taffoureau, Jean-Louis Pinçon, David Mary, Giulia Macario, M. N. El Korso, A. A. Konovalenko, Jean-Jacques Maintoux, W. van Driel, Marcellin Atemkeng, Didier Charrier, Ismaël Cognard, Peter L. Tokarsky, B. Guiderdoni, Benoît Revenu, A. Loh, Annalisa Bonafede, J. Vaubaillon, A. Ferrari, S. Daiboo, S. Masson, M. Serylak, Edith Falgarone, Francoise Combes, F. Levrier, Gilles Theureau, P. Salome, Mykhaylo Panchenko, Arwa Dabbech, M.-A. Miville-Deschenes, B. Semelin, M. Was, Jason W. T. Hessels, J.-M. Griebmeier, Frederic Boone, Carine Briand, Rodolphe Weber, E. Gerard, C. Fevotte, Frederic Rible, S. D. Vergani, V. V. Zakharenko, Cedric Dumez-Viou, V. I. Kondratiev, Julien N. Girard, E. Chassande-Mottin, T. Lanz, L. Lamy, Oleg Smirnov, M. Fullekrug, O. M. Ulyanov, Franco Vazza, Benjamin Stappers, C. Tasse, P. Zarka, M. Tagger, C. Courte, M. Branchesi, Lucas Guillemot, Matt Lehnert, Baptiste Cecconi, Steve Torchinsky, I. Falkovych, D. Oberoi, Richard Dallier, A. Coffre, M. Barsuglia, I. Y. Vasylieva, Stephane Corbel, Katia Ferrière, Helmut O. Rucker, L. Martin, A. Fialkov, S. Celestin, Cédric Richard, Pascal Larzabal, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire des signaux et systèmes (L2S), Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Collège de France - Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Laboratoire d'Etudes et Recherche en Mathématiques Appliquées (LERMA), Ecole Mohammadia d'Ingénieurs (EMI), Laboratoire Energétique Mécanique Electromagnétisme (LEME), Université Paris Nanterre (UPN), Systèmes et Applications des Technologies de l'Information et de l'Energie (SATIE), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École normale supérieure - Rennes (ENS Rennes)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Pluridisciplinaire de Recherche en Ingénierie des Systèmes, Mécanique et Energétique (PRISME), Université d'Orléans (UO)-Ecole Nationale Supérieure d'Ingénieurs de Bourges (ENSI Bourges), NenuFAR, ANR-14-CE23-0004,MAGELLAN,Méthodes d'apprentissage pour les très grands réseaux d'antennes en radioastronomie(2014), 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), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Chaire Galaxies et cosmologie, Université Paris-Seine-Université Paris-Seine-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Ecole Nationale Supérieure d'Ingénieurs de Bourges (ENSI Bourges)-Université d'Orléans (UO), École normale supérieure - Rennes (ENS Rennes)-Université Paris-Sud - Paris 11 (UP11)-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Cachan (ENS Cachan)-Université Gustave Eiffel (UNIV GUSTAVE EIFFEL)
Subjects: Antenna design, 02 engineering and technology, radio astronomy, radio telescope, antenna array, antenna effective area, 01 natural sciences, Antenna array, Radio telescope, [SPI]Engineering Sciences [physics], 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Radiotelescope, Low frequency radioastronomy, Radio astronomy, 010303 astronomy & astrophysics, Antenna Arrays, Physics, Scope (project management), business.industry, NenuFAR, 020206 networking & telecommunications, LOFAR, Pathfinder, Antenna (radio), Telecommunications, business, antennas, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience; NenuFAR is both a giant extension of the LOFAR and a large standalone instrument in the low-frequency range (10-85 MHz). It was designed in Nançay with national and international collaboration. Antenna radiators were modeled on the LWA antenna design whereas preamplifiers were designed in France. Antennas will be distributed in 96 mini-arrays of 19 dual-polarized elements, densely covering a disk of 400 m in diameter. A few mini-arrays are expected to lie at distances of 2-3 km. A silent control-command system was designed, and the computer dialog with LOFAR defined. Receivers will include the LOFAR backend, a local beamformer and a local correlator. NenuFAR is in construction in Nançay and it was recently granted by the SKA office the official label of SKA pathfinder. Its exploitation will expand the scope of LOFAR scientific studies as well as permit new studies, preparing for SKA science. The NenuFAR concept has many points in common with GURT (the Giant Ukrainian Radio Telescope), with which it shares some technical studies, an its exploitation will benefit from a coordination with UTR-2. We describe the instrument, technical developments and science case.
Published: 2015

15. State-of-the-art of low frequency radio astronomy, relevant antenna systems and international cooperation in Ukraine

Author: V. F. Kulishenko, G. Litvinenko, Julien N. Girard, G. Kvasov, Vladimir B. Ryabov, Mykhaylo Panchenko, V. L. Koliadin, Peter L. Tokarsky, I. Y. Vasylieva, S. V. Stepkin, Valentin Melnik, A. Coffre, A. A. Gridin, P. Zarka, A. Reznichenko, J.-M. Griebmeier, O. M. Ulyanov, S. N. Yerin, M. A. Sidorchuk, A. I. Brazhenko, Georg Fischer, M. Tagger, A. A. Konovalenko, V. A. Shepelev, A. D. Khristenko, I. N. Bubnov, V. V. Zakharenko, G. Mann, A. A. Koval, Loïc Denis, A. A. Stanislavsky, A. P. Reznik, Helmut O. Rucker, V. V. Dorovskyy, Didier Charrier, N. N. Kalinichenko, V. Koshovyy, Institute of Radio Astronomy of NASU [Kharkiv] (IRA), National Academy of Sciences of Ukraine (NASU), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Future University-Hakodate, Leibniz-Institut für Astrophysik Potsdam (AIP), Main Astronomical Observatory of NAS of Ukraine (MAO), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, 010504 meteorology & atmospheric sciences, business.industry, Ukrainian, radio interferometry, phased arrays, LOFAR, Low frequency, 01 natural sciences, 7. Clean energy, language.human_language, Radio telescope, radio telescope, Radio propagation beacon, 0103 physical sciences, Very-long-baseline interferometry, language, Antenna (radio), Radio astronomy, Telecommunications, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; The low frequency radio astronomy (decameter-meter range, frequencies of 10-300 MHz) currently demonstrates rapid progress all over the world. New generations of large antennas-LOFAR, LWA, MWA and others – have been created in many countries. At the same time Ukrainian radio astronomical systems UTR-2 and URAN still remain the largest and most informative ones at the lowest frequency range available for the ground-based radio astronomy (below 33 MHz), especially after their radical modernization during the most recent years. A great number of top priority results have been obtained on the basis of these radio telescopes. The results prove a high significance of the low frequency radio astronomy for astrophysics. Substantial part of these results have been obtained in the course of many year cooperation between Ukraine on one side and France, Austria, Germany and other countries on the other. Creation of new low frequency instruments GURT (Ukraine) and LSS/NenuFAR (France) for the wide frequency range of 10-80 MHz opens up new possibilities for research and fruitful cooperation.
Published: 2015

16. Searching for companions down to 2 AU from β Pictoris using the L ′-band AGPM coronagraph on VLT/NACO

Author: Julien Milli, Anne-Marie Lagrange, Christian Delacroix, Gael Chauvin, Jean Surdej, Anthony Boccaletti, Dimitri Mawet, Julien N. Girard, Olivier Absil, European Southern Observatory (ESO), Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), 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), Sibley School of Mechanical and Aerospace Engineering (MAE), Cornell University [New York], Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)
Subjects: FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, law.invention, 010309 optics, Gravitation, Planet, law, 0103 physical sciences, Beta Pictoris, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Coronagraph, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Angular distance, Giant planet, Astronomy and Astrophysics, Orbit, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. The orbit of the giant planet discovered around beta Pic is slightly inclined with respect to the outer parts of the debris disc, which creates a warp in the inner debris disc. This inclination might be explained by gravitational interactions with other planets. Aims. We aim to search for additional giant planets located at smaller angular separations from the star. Methods. We used the new L'-band AGPM coronagraph on VLT/NACO, which provides an exquisite inner working angle. A long observing sequence was obtained on beta Pic in pupil-tracking mode. To derive sensitivity limits, the collected images were processed using a principal-component analysis technique specifically tailored to angular differential imaging. Results. No additional planet is detected down to an angular separation of 0.2" with a sensitivity better than 5 MJup. Meaningful upper limits (< 10 MJup) are derived down to an angular separation of 0.1", which corresponds to 2 AU at the distance of beta Pic., Accepted for publication in A&A Letters
Published: 2013

17. Planetary and exoplanetary low frequency radio observations from the Moon

Author: Philippe Zarka, Laurent Lamy, Baptiste Cecconi, J.-L. Bougeret, Sebastien Hess, C. Briand, David Mimoun, Amin Aminaei, Heino Falcke, A. A. Konovalenko, Julien N. Girard, J.-M. Grießmeier, Marc Klein-Wolt, 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), 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), Department of Astrophysics [Nijmegen], Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University [Nijmegen]-Radboud University [Nijmegen], Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Radio Astronomy of NASU [Kharkiv] (IRA), National Academy of Sciences of Ukraine (NASU), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), and Radboud university [Nijmegen]-Radboud university [Nijmegen]
Subjects: Thermal noise, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy, Hot Jupiters, Uranus, Exoplanetology, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Planets, 01 natural sciences, Lightning, Astrobiology, Jupiter, Neptune, Planet, Saturn, 0103 physical sciences, Hot Jupiter, Radio emission, Moon, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Aurora, Lunar radio array, Galactic background, Exoplanets, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Goniopolarimetry, Exoplanet, 13. Climate action, Space and Planetary Science, Magnetosphere, Physics::Space Physics, Radioastronomy, Astrophysics::Earth and Planetary Astrophysics
Abstract: International audience; We analyze the planetary and exoplanetary science that can be carried out with precursor as well as future low frequency radio instruments on the Moon, assessing the limiting noise sources, comparing them to the average and peak spectra of all planetary radio components as they will be seen from the Lunar surface or orbit. We identify which objectives will be accessible with each class of instrument, and discuss the interest of these observations compared to observations by planetary probes and to ground-based observations by large low-frequency radio arrays. The interest of goniopolarimetry is emphasized for pathfinder missions.
Published: 2012

18. Detecting exoplanets with FAST?

Author: Philippe Zarka, Di Li, Jean-Mathias Grießmeier, Laurent Lamy, Julien N. Girard, Sébastien L. G. Hess, T. Joseph W. Lazio, and Gregg Hallinan
Published: 2019
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18 results on '"Julien N. Girard"'

1. Pilot Study and Early Results of the Cosmic Filaments and Magnetism Survey with Nenufar: The Coma Cluster Field

2. Pilot Study and Early Results of the Cosmic Filaments and Magnetism Survey with Nenufar: The Coma Cluster Field

3. Observations of shock propagation through turbulent plasma in the solar corona

4. Pulsars with NenuFAR: backend and pipelines

5. Phased Subarray of the Low-Frequency Radio Telescope GURT as a Standalone Instrument for Radio Astronomy Studies

6. Exploration of the Potential of the Radio-Detection Technique for the Detection of High-Energy Gamma Rays

7. Detecting exoplanets with FAST?

8. The low-frequency radiotelescope NenuFAR

9. NOIRE study report: Towards a low frequency radio interferometer in space

10. The SHARDDS survey: First resolved image of the HD 114082 debris disk in the Lower Centaurus Crux with SPHERE

11. Astrophysical Studies with Small Low-Frequency Radio Telescopes of New Generation

12. The modern radio astronomy network in Ukraine: UTR-2, URAN and GURT

13. Imaging Jupiter's radiation belts down to 127 MHz with LOFAR

14. NenuFAR: Instrument description and science case

15. State-of-the-art of low frequency radio astronomy, relevant antenna systems and international cooperation in Ukraine

16. Searching for companions down to 2 AU from β Pictoris using the L ′-band AGPM coronagraph on VLT/NACO

17. Planetary and exoplanetary low frequency radio observations from the Moon

18. Detecting exoplanets with FAST?

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18 results on '"Julien N. Girard"'

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