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2,930 results on '"Université d'Orléans (UO)"'

1. A broad-band radio study of PSR J0250+5854

Author: Chun-sheng Zhang, C.H. Agar, A. Loh, V. I. Kondratiev, J. Künsemöller, Benjamin Stappers, J.N. Girard, Jason W. T. Hessels, Aris Karastergiou, L. Bondonneau, Baptiste Cecconi, Jean-Mathias Grießmeier, Charlotte Sobey, C.M. Tan, Di Li, Patrick Weltevrede, B. Peng, Michael Keith, H.G. Wang, Gilles Theureau, W.J. Huang, Philippe Zarka, 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 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), 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 d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), 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 Diderot - Paris 7 (UPD7), 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), High Energy Astrophys. & Astropart. Phys (API, FNWI), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), 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), 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: Astrophysics::High Energy Astrophysical Phenomena, Population, Polarimetry, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, polarisation, magnetars, Magnetar, 01 natural sciences, neutron stars, stars: neutron, stars: magnetars, Pulsar, 0103 physical sciences, education, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, polarization, pulsars: individual: PSR J0250+5854, education.field_of_study, Spectral index, 010308 nuclear & particles physics, Conjunction (astronomy), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, LOFAR, Polarization (waves), PSR J0250+5854, [SDU]Sciences of the Universe [physics], Space and Planetary Science, pulsars, broadband, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We present radio observations of the most slowly rotating known radio pulsar PSR J0250+5854. With a 23.5 s period, it is close, or even beyond, the $P$-$\dot{P}$ diagram region thought to be occupied by active pulsars. The simultaneous observations with FAST, the Chilbolton and Effelsberg LOFAR international stations, and NenuFAR represent a five-fold increase in the spectral coverage of this object, with the detections at 1250 MHz (FAST) and 57 MHz (NenuFAR) being the highest- and lowest-frequency published respectively to date. We measure a flux density of $4\pm2$ $\mu$Jy at 1250 MHz and an exceptionally steep spectral index of $-3.5^{+0.2}_{-1.5}$, with a turnover below $\sim$95 MHz. In conjunction with observations of this pulsar with the GBT and the LOFAR Core, we show that the intrinsic profile width increases drastically towards higher frequencies, contrary to the predictions of conventional radius-to-frequency mapping. We examine polarimetric data from FAST and the LOFAR Core and conclude that its polar cap radio emission is produced at an absolute height of several hundreds of kilometres around 1.5 GHz, similar to other rotation-powered pulsars across the population. Its beam is significantly underfilled at lower frequencies, or it narrows because of the disappearance of conal outriders. Finally, the results for PSR J0250+5854 and other slowly spinning rotation-powered pulsars are contrasted with the radio-detected magnetars. We conclude that magnetars have intrinsically wider radio beams than the slow rotation-powered pulsars, and that consequently the latter's lower beaming fraction is what makes objects such as PSR J0250+5854 so scarce., Comment: 14 pages, 6 figures
Published: 2021

2. Small-time asymptotics of hypoelliptic heat kernels near the diagonal, nilpotentization and related results

Author: Yves Colin de Verdière, Emmanuel Trélat, Luc Hillairet, Institut Fourier (IF), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut Denis Poisson (IDP), Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO), Laboratoire Jacques-Louis Lions (LJLL (UMR_7598)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Control And GEometry (CaGE ), Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jacques-Louis Lions (LJLL (UMR_7598)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), ANR-15-CE40-0018,SRGI,Géométrie sous-Riemannienne et Interactions(2015), Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO), Université d'Orléans (UO)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: Nilpotentization, Pure mathematics, Mathematics::Complex Variables, 010102 general mathematics, Diagonal, Mathematics::Analysis of PDEs, Structure (category theory), Boundary (topology), Ocean Engineering, Sub-Riemannian Laplacian, Mathematics::Spectral Theory, 01 natural sciences, Mathematics - Analysis of PDEs, Small-time asymptotics, Hypoelliptic heat kernel, Hypoelliptic operator, 0103 physical sciences, FOS: Mathematics, [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], 010307 mathematical physics, 0101 mathematics, Smoothing, Analysis of PDEs (math.AP), Mathematics
Abstract: International audience; We establish small-time asymptotic expansions for heat kernels of hypoelliptic Hörmander operators in a neighborhood of the diagonal, generalizing former results obtained in particular by Métivier and by Ben Arous. The coefficients of our expansions are identified in terms of the nilpotentization of the underlying sub-Riemannian structure. Our approach is purely analytic and relies in particular on local and global subelliptic estimates as well as on the local nature of small-time asymptotics of heat kernels. The fact that our expansions are valid not only along the diagonal but in an asymptotic neighborhood of the diagonal is the main novelty, useful in view of deriving Weyl laws for subelliptic Laplacians. In turn, we establish a number of other results on hypoelliptic heat kernels that are interesting in themselves, such as Kac's principle of not feeling the boundary, asymptotic results for singular perturbations of hypoelliptic operators, global smoothing properties for selfadjoint heat semigroups.
Published: 2021

3. Wave equation on certain noncompact symmetric spaces

Author: Hong-Wei Zhang, Institut Denis Poisson (IDP), Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO), and Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO)
Subjects: Pointwise, Pure mathematics, Rank (linear algebra), MSC 1991 : 22E30, 35L05, 43A85, 47J35, 43A90, 010102 general mathematics, Mathematics::Analysis of PDEs, Ocean Engineering, Symmetric space, Wave equation, Dispersive estimate, 01 natural sciences, Mathematics - Analysis of PDEs, Kernel (statistics), 0103 physical sciences, FOS: Mathematics, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], 010307 mathematical physics, [MATH]Mathematics [math], 0101 mathematics, 35Q55, 43A85, 22E30, 35P25, 47J35, 58D25, Linear wave equation, Analysis of PDEs (math.AP), Mathematics
Abstract: In this paper, we prove sharp pointwise kernel estimates and dispersive properties for the linear wave equation on noncompact Riemannian symmetric spaces G/K of any rank with G complex. As a consequence, we deduce Strichartz inequalities for a large family of admissible pairs and prove global well-posedness results for the corresponding semilinear equation with low regularity data as on hyperbolic spaces., Comment: To appear in Pure and Applied Analysis
Published: 2021

4. Steepening of magnetosonic waves in the inner coma of comet 67P/Churyumov–Gerasimenko

Author: Pierre Henri, Hendrik Ranocha, Sang A. Park, Bruce T. Tsurutani, Philip Heinisch, C. Goetz, Karl-Heinz Glassmeier, Ingo Richter, Katharina Ostaszewski, Martin Rubin, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), 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), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley], and University of California
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, 530 Physics, Science, QC1-999, Comet, Geophysics. Cosmic physics, Coma (optics), 01 natural sciences, Article, Physics::Plasma Physics, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Veröffentlichung der TU Braunschweig, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, ddc:5, Physics, QC801-809, 520 Astronomy, Geology, Astronomy and Astrophysics, Plasma, 620 Engineering, Computational physics, Magnetic field, Solar wind, Amplitude, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Physics::Space Physics, Diamagnetism, ddc:52, Astrophysics::Earth and Planetary Astrophysics, Magnetohydrodynamics, Publikationsfonds der TU Braunschweig, ddc:523
Abstract: We present a statistical survey of large-amplitude, asymmetric plasma and magnetic field enhancements detected outside the diamagnetic cavity at comet 67P/Churyumov–Gerasimenko from December 2014 to June 2016. Based on the concurrent observations of plasma and magnetic field enhancements, we interpret them to be magnetosonic waves. The aim is to provide a general overview of these waves' properties over the mission duration. As the first mission of its kind, the ESA Rosetta mission was able to study the plasma properties of the inner coma for a prolonged time and during different stages of activity. This enables us to study the temporal evolution of these waves and their characteristics. In total, we identified ∼ 70 000 steepened waves in the magnetic field data by means of machine learning. We observe that the occurrence of these steepened waves is linked to the activity of the comet, where steepened waves are primarily observed at high outgassing rates. No clear indications of a relationship between the occurrence rate and solar wind conditions were found. The waves are found to propagate predominantly perpendicular to the background magnetic field, which indicates their compressional nature. Characteristics like amplitude, skewness, and width of the waves were extracted by fitting a skew normal distribution to the magnetic field magnitude of individual steepened waves. With increasing mass loading, the average amplitude of the waves decreases, while the skewness increases. Using a modified 1D magnetohydrodynamic (MHD) model, we investigated if the waves can be described by the combination of nonlinear and dissipative effects. By combining the model with observations of amplitude, width and skewness, we obtain an estimate of the effective plasma diffusivity in the comet–solar wind interaction region and compare it with suitable reference values as a consistency check. At 67P/Churyumov–Gerasimenko, these steepened waves are of particular importance as they dominate the innermost interaction region for intermediate to high activity.
Published: 2021

5. Temperley–Lieb, Birman–Murakami–Wenzl and Askey–Wilson Algebras and Other Centralizers of $$U_q(\mathfrak {sl}_2)$$

Author: Luc Vinet, Nicolas Crampé, Meri Zaimi, Fédération de recherche Denis Poisson (FDP), Université d'Orléans (UO)-Université de Tours-Centre National de la Recherche Scientifique (CNRS), and Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)
Subjects: Nuclear and High Energy Physics, Pure mathematics, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Diagonal, FOS: Physical sciences, Duality (optimization), 01 natural sciences, Mathematics::Quantum Algebra, Mathematics - Quantum Algebra, 0103 physical sciences, FOS: Mathematics, Quantum Algebra (math.QA), Representation Theory (math.RT), 0101 mathematics, Mathematics::Representation Theory, Mathematical Physics, Quotient, Mathematics, Conjecture, 010308 nuclear & particles physics, Image (category theory), 010102 general mathematics, Statistical and Nonlinear Physics, Mathematical Physics (math-ph), Mathematics::Geometric Topology, Centralizer and normalizer, Tensor product, Irreducible representation, 20G42, 17B37, 17B35, Mathematics - Representation Theory
Abstract: The centralizer of the image of the diagonal embedding of $U_q(\mathfrak{sl}_2)$ in the tensor product of three irreducible representations is examined in a Schur-Weyl duality spirit. The aim is to offer a description in terms of generators and relations. A conjecture in this respect is offered with the centralizers presented as quotients of the Askey-Wilson algebra. Support for the conjecture is provided by an examination of the representations of the quotients. The conjecture is also shown to be true in a number of cases thereby exhibiting in particular the Temperley-Lieb, Birman-Murakami-Wenzl and one-boundary Temperley-Lieb algebras as quotients of the Askey-Wilson algebra., 26 pages
Published: 2021

6. Development and Implementation of an Experimental Machine to Study Woven Fabric Preforming Defects

Author: Gilles Hivet, Samir Allaoui, Jean Gillibert, Anwar Shanwan, Mécanique des Matériaux et Procédés (MMP), Laboratoire de Mécanique Gabriel Lamé (LaMé), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours-Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours, Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)
Subjects: Mesoscopic physics, Materials science, Mechanical Engineering, Composite number, Process (computing), 02 engineering and technology, Molding (process), 01 natural sciences, 010309 optics, [SPI]Engineering Sciences [physics], 020303 mechanical engineering & transports, 0203 mechanical engineering, Mechanics of Materials, Woven fabric, 0103 physical sciences, Development (differential geometry), Composite material, Buckle, ComputingMilieux_MISCELLANEOUS
Abstract: In Liquid Composite Molding (LCM), a fabric can be formed by highly double curved punch geometries. During the forming step, various types of defects can appear and may have a significant influence on the mechanical properties of the final composite materials. Till now, these defects have not been fully studied and/or understood. The aim of this study was to understand the mechanisms leading to the forming of mesoscopic defects (buckles and sliding), as well as their effect on the behavior of composite materials. To achieve this goal, an experimental machine was designed and built. The machine generates different types of defects, with controlled and adjusted amplitudes (calibrated defects) in samples of a fabric. These samples were then used to manufacture composite samples with calibrated defects, by an LCM process, in order to test and compare them with composite samples without defects. Thanks to this machine, calibrated forming defects that simulate the defects of an LCM process were generated, and the experimental parameters corresponding to the appearance of these defects were defined for two types of fabrics based on glass and carbon fibers. This work provides insight into the forming mechanisms of the buckle and sliding defects that occur during an LCM process.
Published: 2021

7. SPORADIC RADIO EMISSION OF SPACE OBJECTS AT LOW-FREQUENCIES

Author: I. Y. Vasylieva, O. M. Ulyanov, Lpc E, V. V. Zakharenko, Serge Yerin, V. Yu. Kharlanova, I. P. Kravtsov, Jean-Mathias Grießmeier, Lesia, Observatoire de Paris, Cnrs, Psl, Upd, P. Zarka, K. Yu. Mylostna, M. A. Sydorchuk, V. A. Shevchenko, Upmc, A. I. Shevtsova, Georg Fischer, O. O. Konovalenko, Helmut O. Rucker, Vladimir B. Ryabov, A. O. Skoryk, M. M. Kalinichenko, 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 (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: Solar System, transients, 010504 meteorology & atmospheric sciences, Physics and Astronomy (miscellaneous), Astrophysics::High Energy Astrophysical Phenomena, Astronomy, QB1-991, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, UTR-2, 01 natural sciences, Electromagnetic interference, lightning in the atmospheres of planets, Jupiter, Radio telescope, sporadic radio emission, Interference (communication), Pulsar, Planet, 0103 physical sciences, Electrical and Electronic Engineering, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, decameter wavelength range, utr-2, jupiter s-bursts, Astronomy and Astrophysics, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics::Earth and Planetary Astrophysics, Jupiter S-bursts, Noise (radio)
Abstract: International audience; Purpose: The results of studies of sporadic radio emission of several types of space radio sources, including neutron stars and planets of the Solar System, are presented. The aim of this work is to review the latest achievements in the study of low-frequency radio emission of the Solar System planets and transient signals similar to pulsar pulses using the UTR-2 radio telescope. The importance of the development of the verification methods of the spaceborne radio emission in the study of sporadic signals from various sources is shown. Design/methodology/approach: The studies of sporadic signals of different nature are based on the common set of procedures for cleaning records from the terrestrial radio frequency interference (RFI) in the frequency-time pattern using the information on the nature of the particular type of sporadic radio emission, possible types of interference and signal distortion. Characteristic features of sporadic radio emission of different sources are given, and for each of them the optimal method of signal extraction is developed. The efficiency of the developed procedures for cleaning from noise using adjustable parameters is shown. This is done on the basis of observations of diverse types of space radio sources, such as lightnings in the atmospheres of planets, single pulses of neutron stars and sporadic radio emission of Jupiter. Findings: The developed methods of signal extraction detection in the presence of radio-interference have allowed obtaining the unique results such as: the distribution of the total intensity of single pulses of neutron stars depending on the galactic latitude; the automatic search of lightnings in the Saturn’s atmosphere in data due to the carefully elaborated RFI mitigation procedures, which made it possible to obtain the Saturn electrostatic discharge (SED) emission parameters based on the most complete set of events. Increased efficiency of the selection of Jupiter’s S-radiation signals despite the data corruption by the presence of radio-interference, which was reached due to the carefully chosen parameters of data cleaning procedures, have allowed us to detect short and intensive bursts, being the most informative for determining the physical parameters of radio emission in the area of their generation. Conclusions: The large effective area and high sensitivity of the UTR-2 radio telescope allow making the sporadic radio emission study with high temporal and frequency resolutions. Due to these factors we can apply a wide range of methods of space signals’ detection in the presence of terrestrial radio-frequency interference of natural and artificial origin. The data cleaning parameters allow accounting for the characteristic features of space signals and to obtain important and even unique scientific results. Key words: decameter wavelength range; UTR-2; sporadic radio emission; transients; lightning in the atmospheres of planets; Jupiter S-bursts
Published: 2021

8. Ion acoustic waves near a comet nucleus: Rosetta observations at comet 67P/Churyumov–Gerasimenko

Author: H. Gunell, C. Goetz, E. Odelstad, A. Beth, M. Hamrin, P. Henri, F. L. Johansson, H. Nilsson, G. Stenberg Wieser, Umeå University, European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Royal Institute of Technology [Stockholm] (KTH ), 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), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Swedish Institute of Space Physics [Kiruna] (IRF), and ANR-15-CE31-0009,SPECTRA,Sonder le Plasma dans l'Environnement d'une ComètE avec RosettA(2015)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Comet, Population, Plasma oscillation, 7. Clean energy, 01 natural sciences, Ion, Spacecraft charging, Fusion, plasma och rymdfysik, Dispersion relation, Comet nucleus, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), education, lcsh:Science, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, education.field_of_study, lcsh:QC801-809, Geology, Astronomy and Astrophysics, Acoustic wave, Fusion, Plasma and Space Physics, lcsh:QC1-999, Computational physics, lcsh:Geophysics. Cosmic physics, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, lcsh:Q, Astrophysics::Earth and Planetary Astrophysics, lcsh:Physics
Abstract: Ion acoustic waves were observed between 15 and 30 km from the centre of comet 67P/Churyumov–Gerasimenko by the Rosetta spacecraft during its close flyby on 28 March 2015. There are two electron populations: one cold at kBTe≈0.2 eV and one warm at kBTe≈2 eV. The ions are dominated by a cold (a few hundredths of electronvolt) distribution of water group ions with a bulk speed of (3–3.7) km s−1. A warm kBTe≈6 eV ion population, which also is present, has no influence on the ion acoustic waves due to its low density of only 0.25 % of the plasma density. Near closest approach the propagation direction was within 50∘ from the direction of the bulk velocity. The waves, which in the plasma frame appear below the ion plasma frequency fpi≈2 kHz, are Doppler-shifted to the spacecraft frame where they cover a frequency range up to approximately 4 kHz. The waves are detected in a region of space where the magnetic field is piled up and draped around the inner part of the ionised coma. Estimates of the current associated with the magnetic field gradient as observed by Rosetta are used as input to calculations of dispersion relations for current-driven ion acoustic waves, using kinetic theory. Agreement between theory and observations is obtained for electron and ion distributions with the properties described above. The wave power decreases over cometocentric distances from 24 to 30 km. The main difference between the plasma at closest approach and in the region where the waves are decaying is the absence of a significant current in the latter. Wave observations and theory combined supplement the particle measurements that are difficult at low energies and complicated by spacecraft charging.
Published: 2021

9. Capabilities and limitations of Large Eddy Simulation with perfectly stirred reactor assumption for engineering applications of unsteady, hydrogen combustion sequences

Author: F. J. S. Velasco, Nabiha Chaumeix, A. Bentaib, F. Nicolás-Pérez, R.A. Otón-Martínez, Jose Ramon Garcia-Cascales, Universidad Politécnica de Cartagena / Technical University of Cartagena (UPCT), University Centre of Defence at the Spanish Air Force Academy, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut des Sciences de l'Ingénierie et des Systèmes (INSIS - CNRS), Institut of Radioprotection et Sûreté Nucléaire of France [DA 3000011012/CA32000911], Spanish Ministry of Economy and Competitiveness, European Project: ERDF, Technical University of Cartagena (UPTC), Institut de Radioprotection et de Sûreté Nucléaire, Fontenay-aux-Roses, and Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut des Sciences de l'Ingénierie et des Systèmes (INSIS)
Subjects: Work (thermodynamics), General Computer Science, unsteady, Hydrogen combustion, Nuclear engineering, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, 02 engineering and technology, Engineering (General). Civil engineering (General), 01 natural sciences, 010305 fluids & plasmas, perfectly stirred reactor, fast combustion, 020401 chemical engineering, Perfectly stirred reactor, Modeling and Simulation, 0103 physical sciences, 0204 chemical engineering, implicit les, TA1-2040, Large eddy simulation
Abstract: International audience; This work evaluates the capabilities of Large Eddy Simulation with perfectly stirred reactor (PSR) assumption and detailed chemistry to predict unsteady, premixed, hydrogen combustion sequences. The model was benchmarked with hydrogen-air experimental tests and with numerical data of flame acceleration in an obstructed channel. Results permit to identify major shortcomings that should be addressed with this approach and to assess the uncertainties linked to the use of different sub-models. Spatial resolution was found to be critical and limits the applications of this approach due to the increase of the computational costs with the flame surface. While the influence of the detailed kinetic chemical scheme used was low, the impact of the sub-grid turbulence model used was high. Results showed that simulations provided good agreement with the experimental data when a minimum spatial resolution of 1/8 of the laminar flame thickness was imposed. This threshold permits to simulate with good results the early stages of the combustion sequence (ignition and initial flame acceleration) but limits the model applications when the flame surface increases. In-situ Adaptive Tabulation (ISAT) was an effective strategy to overcome the limitations and partially reduce the computational cost when detailed chemistry models are used together with PSR-LES.
Published: 2021

10. LeMMINGs - II. The e-MERLIN legacy survey of nearby galaxies. The deepest radio view of the Palomar sample on parsec scale

Author: David A. Green, Elmar Körding, Susanne Aalto, David R. Williams, Bililign T. Dullo, Alison B. Peck, Ranieri D. Baldi, C. Romero-Cañizales, Willem A. Baan, I. M. McHardy, Megan Argo, Eskil Varenius, Antxon Alberdi, Miguel A. Pérez-Torres, Payaswini Saikia, Francesca Panessa, Stephane Corbel, John S. Gallagher, Martin Ward, R. C. Kennicutt, George J. Bendo, Jeremy Yates, Francesco Shankar, P. Uttley, Hans-Rainer Klöckner, Ralph Spencer, T. J. Maccarone, Johan H. Knapen, Ian R. Stevens, Danielle Fenech, T. W. B. Muxlow, C. G. Mundell, Robert Beswick, Elias Brinks, 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), 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), Ministerio de Ciencia, Innovación y Universidades (España), Comunidad de Madrid, Universidad Complutense de Madrid, University of Bath, University of Wisconsin-Madison, European Commission, Green, David [0000-0003-3189-9998], Apollo - University of Cambridge Repository, 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), 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), and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)
Subjects: Astrofísica, active [Galaxies], galaxies: jet, media_common.quotation_subject, Astronomy, galaxies: active, FOS: Physical sciences, Scale (descriptive set theory), Astrophysics, F500, galaxies [Radio continuum], 01 natural sciences, jet [Galaxies], star formation [Galaxies], Spectral line, Parsec, 0103 physical sciences, 010303 astronomy & astrophysics, MERLIN, media_common, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), radio continuum: galaxies, 010308 nuclear & particles physics, Astronomy and Astrophysics, Sample (graphics), Astrophysics - Astrophysics of Galaxies, Galaxy, Universe, Astronomía, Space and Planetary Science, nuclei [Galaxies], Astrophysics of Galaxies (astro-ph.GA), galaxies: star formation, galaxies: nuclei, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Data release
Abstract: Full list of authors: Baldi, R. D.; Williams, D. R. A.; McHardy, I. M.; Beswick, R. J.; Brinks, E.; Dullo, B. T.; Knapen, J. H.; Argo, M. K.; Aalto, S.; Alberdi, A.; Baan, W. A.; Bendo, G. J.; Corbel, S.; Fenech, D. M.; Gallagher, J. S.; Green, D. A.; Kennicutt, R. C.; Klöckner, H. -R.; Körding, E.; Maccarone, T. J.; Muxlow, T. W. B.; Mundell, C. G.; Panessa, F.; Peck, A. B.; Pérez-Torres, M. A.; Romero-Cañizales, C.; Saikia, P.; Shankar, F.; Spencer, R. E.; Stevens, I. R.; Varenius, E.; Ward, M. J.; Yates, J.; Uttley, P., We present the second data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 177 nearby galaxies from the Palomar sample, observed with the e-MERLIN array, as part of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies Sample (LeMMINGs) survey. Together with the 103 targets of the first LeMMINGs data release, this represents a complete sample of 280 local active (LINER and Seyfert) and inactive galaxies (H ii galaxies and absorption line galaxies, ALG). This large program is the deepest radio survey of the local Universe, ≳1017.6 W Hz-1, regardless of the host and nuclear type: we detect radio emission ≳0.25 mJy beam-1 for 125/280 galaxies (44.6 per cent) with sizes of typically ≲100 pc. Of those 125, 106 targets show a core which coincides within 1.2 arcsec with the optical nucleus. Although we observed mostly cores, around one third of the detected galaxies features jetted morphologies. The detected radio core luminosities of the sample range between ∼1034 and 1040 erg s-1. LINERs and Seyferts are the most luminous sources, whereas H ii galaxies are the least. LINERs show FR I-like core-brightened radio structures while Seyferts reveal the highest fraction of symmetric morphologies. The majority of H ii galaxies have single radio core or complex extended structures, which probably conceal a nuclear starburst and/or a weak active nucleus (seven of them show clear jets). ALGs, which are typically found in evolved ellipticals, although the least numerous, exhibit on average the most luminous radio structures, similar to LINERs. © 2020 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society., The authors thank the anonymous referee for his/her helpful comments to improve the manuscript. AA and MAPT acknowledge support from the Spanish MCIU through grant PGC2018-098915-B-C21 and from the State Agency for Research of the Spanish MCIU through the 'Center of Excellence Severo Ochoa' award for the Instituto de Astrof ' isica de Andalucia (SEV-2017-0709). BTD acknowledges support from a Spanish postdoctoral fellowship 'Ayudas 1265 para la atraccion del talento investigador. Modalidad 2: jovenes investigadores.' funded by Comunidad de Madrid under grant number 2016-T2/TIC-2039. BTD also acknowledges support from grant 'Ayudas para la realizaci on de proyectos de I + D para jovenes doctores 2019.' funded by Comunidad de Madrid and Universidad Complutense de Madrid under grant number PR65/19-22417. JHK acknowledges financial support from the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No. 721463 to the SUNDIAL ITN network, from the State Research Agency (AEI-MCINN) of the Spanish Ministry of Science and Innovation under the grant 'The structure and evolution of galaxies and their central regions' with reference PID2019-105602GB-I00/10.13039/501100011033, and from IAC project P/300724, financed by the Ministry of Science and Innovation, through the State Budget and by the Canary Islands Department of Economy, Knowledge and Employment, through the Regional Budget of the Autonomous Community. JSG thanks the University of Wisconsin-Madison and its Foundation for support of this research through his Rupple Bascom Professorship. FS acknowledges partial support from a Leverhulme Trust Research fellowship. CGM acknowledges support from the University of Bath and Jim and Hiroko Sherwin. e-MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC, part of UK Research and Innovation.
Published: 2021

11. Measuring the distance to the black hole candidate X-ray binary MAXI J1348–630 using H <scp>i</scp> absorption

Author: J. C. A. Miller-Jones, Rob Fender, G. E. Anderson, W. Raja, Patrick Woudt, Matthew Whiting, Jai Verdhan Chauhan, B. S. Koribalski, P. F. L. Jacob, James R. Allison, Elizabeth K. Mahony, S. Corbel, F. Carotenuto, Aidan Hotan, 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), 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)-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), 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), 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, and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Absorption spectroscopy, black hole physics, X-ray binary, FOS: Physical sciences, Binary number, Astrophysics, 01 natural sciences, Spectral line, X-rays: binaries, symbols.namesake, radio continuum: transients, 0103 physical sciences, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Local standard of rest, X-rays: individual: MAXI J1348–630, Astronomy and Astrophysics, Radial velocity, ISM: jets and outflows, Space and Planetary Science, Eddington luminosity, symbols, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We present HI absorption spectra of the black hole candidate X-ray binary (XRB) MAXI J1348-630 using the Australian Square Kilometre Array Pathfinder (ASKAP) and MeerKAT. The ASKAP HI spectrum shows a maximum negative radial velocity (with respect to the local standard of rest) of $-31\pm4$ km s$^{-1}$ for MAXI J1348-630, as compared to $-50\pm4$ km s$^{-1}$ for a stacked spectrum of several nearby extragalactic sources. This implies a most probable distance of $2.2^{+0.5}_{-0.6}$ kpc for MAXI J1348-630, and a strong upper limit of the tangent point distance at $5.3\pm0.1$ kpc. Our preferred distance implies that MAXI J1348-630 reached $17\pm10$ % of the Eddington luminosity at the peak of its outburst, and that the source transited from the soft to the hard X-ray spectral state at $2.5\pm1.5$ % of the Eddington luminosity. The MeerKAT HI spectrum of MAXI J1348-630 (obtained from the older, low-resolution 4k mode) is consistent with the re-binned ASKAP spectrum, highlighting the potential of the eventual capabilities of MeerKAT for XRB spectral line studies., Comment: Accepted for publication in MNRAS Letters
Published: 2020

12. Walkers in a wave field with memory

Author: Olivier Devauchelle, Christophe Josserand, François James, Eric Lajeunesse, Pierre-Yves Lagrée, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut Denis Poisson (IDP), Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO), Laboratoire d'hydrodynamique (LadHyX), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut Jean Le Rond d'Alembert (DALEMBERT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO)
Subjects: Physics, Wave-particle interaction, Faraday waves, Field (physics), Helmholtz equation, Walking droplets, 01 natural sciences, Non-linear dynamics, 010305 fluids & plasmas, Faraday wave, Nonlinear system, symbols.namesake, Mechanics of Materials, Quantum electrodynamics, 0103 physical sciences, symbols, General Materials Science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], 010306 general physics, MSC 2020 : 76B15, 35Q35, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2020

13. Rapid compact jet quenching in the Galactic black hole candidate X-ray binary MAXI J1535−571

Author: Wanga Mulaudzi, Marco Toliman Lucchini, Diego Altamirano, Aastha S. Parikh, Roberto Soria, Sera Markoff, G. R. Sivakoff, Nathalie Degenaar, Rudy Wijnands, Stephane Corbel, Maria Cristina Baglio, D. M. Russell, D. Maitra, Chiara Ceccobello, Thomas D. Russell, Simone Migliari, Michael P. Rupen, Rob Fender, Karri I. I. Koljonen, J. van den Eijnden, Felicia Krauß, Sebastian Heinz, Craig L. Sarazin, James Miller-Jones, Richard M. Plotkin, Alexandra J. Tetarenko, 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), 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), University of Amsterdam, East Asian Observatory, Curtin University, University of Alberta, University of Cape Town, New York University Abu Dhabi, University of Southampton, Chalmers University of Technology, Université Paris-Diderot, University of Oxford, University of Wisconsin-Madison, Metsähovi Radio Observatory, Wheaton College Massachusetts, European Space Astronomy Centre, University of Nevada, Reno, National Research Council of Canada, University of Virginia, University of Chinese Academy of Sciences, Aalto-yliopisto, Aalto University, High Energy Astrophys. & Astropart. Phys (API, FNWI), 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), 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: Acceleration of particles, Accretion, submillimetre: general, general [Submillimetre], Radiative cooling, Infrared, Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, FOS: Physical sciences, Astrophysics, 01 natural sciences, Radio spectrum, X-rays: binaries, accretion, 0103 physical sciences, individual (MAXI J1535−571) [X-rays], Jet quenching, 010303 astronomy & astrophysics, acceleration of particles, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, jets and outflows [ISM], 010308 nuclear & particles physics, Astronomy and Astrophysics, accretion discs, Magnetic field, Black hole, Particle acceleration, X-rays: individual (MAXI J1535−571), ISM: jets and outflows, 13. Climate action, Space and Planetary Science, binaries [X-rays], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena, Accretion discs
Abstract: We present results from six epochs of quasi-simultaneous radio, (sub-)millimetre, infrared, optical, and X-ray observations of the black hole X-ray binary MAXI~J1535$-$571. These observations show that as the source transitioned through the hard-intermediate X-ray state towards the soft intermediate X-ray state, the jet underwent dramatic and rapid changes. We observed the frequency of the jet spectral break, which corresponds to the most compact region in the jet where particle acceleration begins (higher frequencies indicate closer to the black hole), evolve from the IR band into the radio band (decreasing by $\approx$3 orders of magnitude) in less than a day. During one observational epoch, we found evidence of the jet spectral break evolving in frequency through the radio band. Estimating the magnetic field and size of the particle acceleration region shows that the rapid fading of the high-energy jet emission was not consistent with radiative cooling; instead the particle acceleration region seems to be moving away from the black hole on approximately dynamical timescales. This result suggests that the compact jet quenching is not caused by local changes to the particle acceleration, rather we are observing the acceleration region of the jet travelling away from the black hole with the jet flow. Spectral analysis of the X-ray emission show a gradual softening in the few days before the dramatic jet changes, followed by a more rapid softening $\sim$1--2\,days after the onset of the jet quenching., 17 pages, 6 figures, data provided in the appendices. Accepted for publication in MNRAS
Published: 2020

14. Modeling of the Electromechanical Behavior of Barium Titanate Under Mechanical Stress and Comparison With Experimental Measurements

Author: Michael Lematre, L.P. Tran-Huu-Hue, Remy Ul, Michel Gratton, Marc Lethiecq, GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Mécanique des Matériaux et Procédés (MMP), Laboratoire de Mécanique Gabriel Lamé (LaMé), Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Materials science, Acoustics and Ultrasonics, chemistry.chemical_element, Order (ring theory), Barium, [SPI.MECA.MSMECA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Materials and structures in mechanics [physics.class-ph], Lead zirconate titanate, 01 natural sciences, Piezoelectricity, Displacement (vector), [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, Transducer, chemistry, 0103 physical sciences, Barium titanate, Electrical and Electronic Engineering, Composite material, 010301 acoustics, Instrumentation, ComputingMilieux_MISCELLANEOUS
Abstract: Barium titanate (BaTiO3) is increasingly studied to replace lead-based piezoelectric materials, such as those which belong to the lead zirconate titanate (PZT) family, due to lead toxicity. In many applications, such as Tonpilz transducers, piezoelectric materials undergo mechanical stress simulation of which is important to control and predict electroacoustic effects. Thus, this article deals with a fully tensorial model that allows to simulate the behaviors of electrical displacements and elastic strains under mechanical stress. Simulated curves are compared with experimental ones obtained for BaTiO3 samples. It can be verified that the hysteretic curves of strains are well predicted for unpoled samples as well as for poled ones. The order of values and global behavior of the theoretical electrical displacement are also verified, even if a less precise agreement is observed. The optimized values of the physical parameters, such as ${d}_{{{33}}}$ , are discussed, and improvements both of the model and the optimization procedure are finally proposed in order to better predict the mechanical behavior of BaTiO3.
Published: 2020

15. Addressing the cosmological $$H_0$$ tension by the Heisenberg uncertainty

Author: Micol Benetti, Salvatore Capozziello, Alessandro D. A. M. Spallicci, 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), 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), Capozziello, Salvatore, Benetti, Micol, and Spallicci, Alessandro D. A. M.
Subjects: High Energy Physics - Theory, Observational cosmology, cosmological model, Uncertainty principle, constraint, General relativity, Initial singularity, Cosmic microwave background, Cosmic background radiation, FOS: Physical sciences, Hubble-Lemaître constant, General Physics and Astronomy, General Relativity and Quantum Cosmology (gr-qc), cosmic background radiation, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, General Relativity and Quantum Cosmology, Theoretical physics, Singularity, 0103 physical sciences, general relativity, uncertainty relations, 010303 astronomy & astrophysics, Physics, Hubble constant, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, quantum mechanics, tension, redshift, 16. Peace & justice, Redshift, big bang: singularity, Heisenberg, High Energy Physics - Theory (hep-th), kinematics, [SDU]Sciences of the Universe [physics], [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], mass, Heisenberg principle
Abstract: The uncertainty on measurements, given by the Heisenberg principle, is a quantum concept usually not taken into account in General Relativity. From a cosmological point of view, several authors wonder how such a principle can be reconciled with the Big Bang singularity, but, generally, not whether it may affect the reliability of cosmological measurements. In this letter, we express the {Compton mass} as a function of the cosmological redshift. The cosmological application of the indetermination principle unveils the differences of the Hubble-Lema\^{i}tre constant value, $H_0$, as measured from the Cepheids estimates and from the Cosmic Microwave Background radiation constraints. In conclusion, the $H_0$ tension could be related to the effect of indetermination derived in comparing a kinematic with a dynamic measurement., Comment: 7 pages, 1 figure, accepted for publication in Foundations of Physics
Published: 2020

16. X‐ray photoelectron spectroscopy characterization of Cu compounds for the development of organic protection treatments dedicated to heritage Cu objects preservation

Author: Muriel Bouttemy, Arnaud Etcheberry, Florence Mercier-Bion, Emilande Apchain, Philippe Dillmann, Maëva L’héronde, Delphine Neff, Laboratoire Archéomatériaux et Prévision de l'Altération (LAPA - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), 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-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), 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-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut photonique d'analyse non-destructive européen des matériaux anciens (IPANEMA), Muséum national d'Histoire naturelle (MNHN)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), IRAMAT - Laboratoire Métallurgies et Cultures (IRAMAT - LMC), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Fondation des Sciences du Patrimoine, Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), 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-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), and 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-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: 010302 applied physics, Cuprite, Materials science, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Surfaces and Interfaces, General Chemistry, engineering.material, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Surfaces, Coatings and Films, Characterization (materials science), X-ray photoelectron spectroscopy, 13. Climate action, visual_art, 0103 physical sciences, Materials Chemistry, engineering, visual_art.visual_art_medium, Brochantite, 0210 nano-technology, Nuclear chemistry
Abstract: International audience; The preservation of bronze and copper heritage objects is challenging. Exposure to water or pollution in outdoor conditions leads to corrosion phenomena, which can highly degrade the objects or structures. We aim to develop an alternative nontoxic corrosion inhibiting treatment, based on the use of a carboxylate (HC10) treatment. Electron spectroscopies (X‐ray photoelectron spectroscopy and scanning Auger microscopy) are used to determine, from micrometric to nanometric scale, the composition and chemical environments (oxidation degrees) of the copper compounds commonly found in the corrosion product layer. In the present study, we focus on the evaluation of X‐ray beam irradiation damage when performing surface analysis on cuprite, brochantite, and Cu decanoate reference samples. The reduction phenomenon has already been reported, especially for Cu(II) compounds, but not clearly explained. Different behavior has been observed depending on the X‐ray source used, and the nature and hydration level of the compounds. The photoreduction issue is critical, as it guarantees the reliability of the chemical information obtained and sheds light on the best analysis pathway to adopt when multitechnique analyses are implemented. An analytical procedure is employed to track the reduction of Cu(II) reference samples during XPS analysis evidencing practically instantaneous modifications of the spectra and thus, the instability of these phases except for the dehydrated cuprite sample.
Published: 2020

17. Self-combustion of Ti-C and Ti-Al Powder Mixture in a Nitrogen Atmosphere: Product Application as Reinforcement in Metal Matrix Composites

Author: Said Seghar, Akram Alhussein, Clémence Fradet, Salem Dehlouz, Florian Lacroix, Said Azem, Laboratoire des Systèmes Mécaniques et d'Ingénierie Simultanée (LASMIS), Institut Charles Delaunay (ICD), Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS), Mécanique des Matériaux et Procédés (MMP), Laboratoire de Mécanique Gabriel Lamé (LaMé), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT), Laboratoire de Mécanique et de Rhéologie (LMR), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Polytech'Tours, Université Mouloud Mammeri [Tizi Ouzou] (UMMTO), Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Université de Tours-Polytech'Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques (CRAPC), and Université d'Orléans (UO)-Université de Tours (UT)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL)
Subjects: Ti2AlN, Materials science, Composite number, Sintering, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, SHS, chemistry.chemical_compound, 0103 physical sciences, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, General Materials Science, Composite material, ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], 010302 applied physics, Titanium aluminide, Mechanical Engineering, nitrogen atmosphere, metal matrix composites (MMCs), [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], Nanoindentation, Tribology, 021001 nanoscience & nanotechnology, chemistry, Mechanics of Materials, Wetting, 0210 nano-technology, Tin, mechanical and tribological properties, Ti(C N), Solid solution
Abstract: International audience; In this work, two copper metal matrix composites (MMCs) reinforced with 20 wt.% of Ti(C,N) or Ti2AlN particles were studied. The reinforcement particles were synthesized by flash sintering under 2 bar nitrogen atmosphere causing an SHS reaction ignited by electrical current. This reaction led to produce TiC0.7N0.3 solid solution for the MMC1 reinforcement and Ti2AlN, TiN, and Ti3Al titanium aluminide for the MMC2 reinforcement. Both MMCs were densified by liquid phase sintering. The structural characterization was performed by XRD analysis while the morphology and chemical element distribution of both MMCs were analyzed by SEM and EDS. The structure of the two MMCs was relatively dense and showed good wettability. The mechanical and tribological behavior of MMCs evaluated by nanoindentation and wear testing reveals that the addition of 20 wt.% of reinforcement considerably improves the properties of copper matrix. Indeed, the MMC1 proved to be 3 times harder and 10 times more wear-resistant than the MMC2 composite.
Published: 2020

18. Effect of Hydrated Lime and Cement on the Engineering Behavior of Highly Expansive Clay

Author: Alain Jacquet, Muzahim Al-Mukhtar, Kévin Beck, Serge Sabio, Nouffou Tapsoba, Marwen Bouasker, Fawzi Bouras, Mylène Martin, Naima Belayachi, Beck, Kevin, Lafarge Centre de Recherche [Lyon] (Lafarge LCR Lyon), Lafarge, Génie Civil (GC), Laboratoire de Mécanique Gabriel Lamé (LaMé), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT), Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: 010302 applied physics, Cement, Materials science, Expansive clay, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, 02 engineering and technology, General Medicine, engineering.material, 021001 nanoscience & nanotechnology, 01 natural sciences, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, 0103 physical sciences, engineering, [SPI.GCIV] Engineering Sciences [physics]/Civil Engineering, Geotechnical engineering, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Lime
Abstract: International audience
Published: 2020

19. A Shapiro delay detection in the pulsar binary system PSR J1811–2405

Author: Lucas Guillemot, Ewan Barr, Ismaël Cognard, Michael Kramer, D. J. Champion, Gilles Theureau, Cherry Ng, Paulo C. C. Freire, 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), 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), Laboratoire Univers et Théories (LUTH (UMR_8102)), 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, 010308 nuclear & particles physics, Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, pulsars: individual: PSR J1811–2405, Binary number, Astronomy and Astrophysics, Astrophysics, Orbital period, 01 natural sciences, Shapiro delay, Orbital inclination, stars: neutron, Pulsar, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, Binary system, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], pulsars: binaries, 010303 astronomy & astrophysics
Abstract: This paper presents the first detection of Shapiro delay from the binary millisecond pulsar PSR J1811–2405. We report a 11σ measurement of the orthometric amplitude, h3 = 6.8(6) × 10−7, and a 16σ measurement of the orthometric ratio, ς = 0.81(5). Given the relatively high orbital inclination, i = 79(2)°, of this binary system, we obtain constraints on the companion mass of $m_{\rm {c}}=0.31^{+0.08 }_{ -0.06}\, \mathrm{M}_{\odot }$. The pulsar mass is currently less well constrained, with a value of $2.0^{+0.8 }_{ -0.5}\, \mathrm{M}_{\odot }$. The companion mass and the orbital period are in agreement with the prediction made by previous numerical calculations of the evolution of compact binary systems. From a study of the polarization, we find that the orbital inclination angle is ∼100° and that PSR J1811–2405 is an orthogonal rotator. In addition, the μs-level timing precision together with its narrow profile makes PSR J1811–2405 a good candidate for inclusion in the pulsar timing arrays being used to detect nHz gravitational waves.
Published: 2020

20. The Giant Radio Array for Neutrino Detection (GRAND): Science and design

Author: GRAND Collaboration, Alvarez-Muniz, Jaime, Batista, Rafael Alves, V., Aswathi Balagopal, Bolmont, Julien, Bustamante, Mauricio, Carvalho, Washington R., Charrier, Didier, Cognard, Ismael, Decoene, Valentin, Denton, Peter B., De Jong, Sijbrand J., De Vries, Krijn D., Engel, Ralph, Fang, Ke, Finley, Chad, Gabici, Stefano, Gou, QuanBu, Gu, Junhua, Guépin, Claire, Hu, Hongbo, Huang, Yan, Kotera, Kumiko, Coz, Sandra Le, Lenain, Jean-Philippe, Lu, Guo-Liang, Martineau-Huynh, Olivier, Mostafá, Miguel, Mottez, Fabrice, Murase, Kohta, Niess, Valentin, Oikonomou, Foteini, Pierog, Tanguy, Qian, Xiangli, Qin, Bo, Ran, Duan, Renault-Tinacci, Nicolas, Roth, Markus, Schröder, Frank G., Schüssler, Fabian, Tasse, Cyril, Timmermans, Charles, Tueros, Matias, Wu, Xiangping, Zarka, Philippe, Zech, Andreas, Zhang, B. Theodore, Zhang, Jianli, Zhang, Yi, Zheng, Qian, Zilles, Anne, 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), 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), 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)-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, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), 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)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Galaxies, Etoiles, Physique, Instrumentation (GEPI), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Saarland University [Saarbrücken], Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), 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), 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), 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), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), 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 (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), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), 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, 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE31-0001,APACHE,Astroparticules et pulsars : connexions de basse à ultra-haute énergies(2016), Physics, and Elementary Particle Physics
Subjects: HIGH-ENERGY NEUTRINOS, cosmic radiatio, General Physics and Astronomy, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), Observatory, modular, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, COSMIC cancer database, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, COSMIC-RAYS, neutrino: UHE, BURST, observatory, High Energy Physics - Phenomenology, galactic and extragalactic, Neutrino detector, radio wave: det, Neutrino, Astrophysics - High Energy Astrophysical Phenomena, radio telescopes, performance, air, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], PAIR PRODUCTION, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, galactic and extragalactic [cosmic rays], EXTENSIVE AIR-SHOWERS, LIMIT, 0103 physical sciences, High Energy Physics, sources [radiowave radiation], 010306 general physics, SPECTRUM, neutrinos in astronomical observations, Astronomy, sensitivity, Construction plan, showers: atmosp, SIMULATIONS, PULSES, cosmic rays in astronomical observations, gamma ray, EMISSION
Abstract: The Giant Radio Array for Neutrino Detection (GRAND) is a planned large-scale observatory of ultra-high-energy (UHE) cosmic particles, with energies exceeding 10^8 GeV. Its goal is to solve the long-standing mystery of the origin of UHE cosmic rays. To do this, GRAND will detect an unprecedented number of UHE cosmic rays and search for the undiscovered UHE neutrinos and gamma rays associated to them with unmatched sensitivity. GRAND will use large arrays of antennas to detect the radio emission coming from extensive air showers initiated by UHE particles in the atmosphere. Its design is modular: 20 separate, independent sub-arrays, each of 10 000 radio antennas deployed over 10 000 km^2. A staged construction plan will validate key detection techniques while achieving important science goals early. Here we present the science goals, detection strategy, preliminary design, performance goals, and construction plans for GRAND., 45 pages, 34 figures. Matches published version
Published: 2020

21. Potential of N2/O2atmospheric pressure needle-water DC microplasmas for nitrogen fixation: nitrite-free synthesis of nitrates

Author: Nepal Chandra Roy, David Petitjean, Cedric Pattyn, Nicolas Maira, Sylvain Iseni, François Reniers, Antoine Remy, Faculté des Sciences [Bruxelles] (ULB), Université libre de Bruxelles (ULB), Groupe de recherches sur l'énergétique des milieux ionisés (GREMI), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)
Subjects: Materials science, Absorption spectroscopy, Inorganic chemistry, General Physics and Astronomy, 02 engineering and technology, 7. Clean energy, 01 natural sciences, law.invention, Physico-chimie générale, chemistry.chemical_compound, [CHIM.GENI]Chemical Sciences/Chemical engineering, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], law, 0103 physical sciences, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Physical and Theoretical Chemistry, Nitrite, 010302 applied physics, Atmospheric pressure, Physique, Microplasma, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.PLASMA]Engineering Sciences [physics]/Plasmas, Aqueous two-phase system, Chimie théorique, Plasma, Astronomie, 021001 nanoscience & nanotechnology, 6. Clean water, Cathode, Anode, chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 0210 nano-technology
Abstract: A needle-water DC microplasma system working at atmospheric pressure in N2/O2 gas mixtures is used to study the fundamental mechanisms of nitrate/nitrite synthesis in highly complex and yet little-known plasma-water systems. Plasma properties are investigated by means of optical emission spectroscopy while the activated water is analyzed following the treatment using ionic chromatography and UV-Vis absorbance spectroscopy. Experiments highlight that the energy efficiency and selectivity of the process are influenced by the oxygen content and the plasma-induced water heating, with strong differences when the water surface is the anode or the cathode electrode. Nitrates are successfully synthesized without residual nitrites in the solution with a comparatively higher energy efficiency when the water is the cathode. The possible reactions involved in the gas phase and aqueous phase chemistry are presented and future scope for the optimization of the system is discussed., SCOPUS: ar.j, info:eu-repo/semantics/published
Published: 2020

22. Dual-frequency single-pulse study of PSR B0950+08

Author: A. V. Bilous, J. M. Grießmeier, T. Pennucci, Z. Wu, L. Bondonneau, V. Kondratiev, J. van Leeuwen, Y. Maan, L. Connor, L. C. Oostrum, E. Petroff, J. P. W. Verbiest, D. Vohl, J. W. McKee, G. Shaifullah, G. Theureau, O. M. Ulyanov, B. Cecconi, A. H. Coolen, S. Corbel, S. Damstra, H. Dénes, J. N. Girard, B. Hut, M. Ivashina, O. O. Konovalenko, A. Kutkin, G. M. Loose, H. Mulder, M. Ruiter, R. Smits, P. L. Tokarsky, N. J. Vermaas, V. V. Zakharenko, P. Zarka, J. Ziemke, High Energy Astrophys. & Astropart. Phys (API, FNWI), 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), 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), 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), 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 Diderot - Paris 7 (UPD7), 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), 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), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), 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), 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), Bilous, A, Griessmeier, J, Pennucci, T, Wu, Z, Bondonneau, L, Kondratiev, V, van Leeuwen, J, Maan, Y, Connor, L, Oostrum, L, Petroff, E, Verbiest, J, Vohl, D, Mckee, J, Shaifullah, G, Theureau, G, Ulyanov, O, Cecconi, B, Coolen, A, Corbel, S, Damstra, S, Denes, H, Girard, J, Hut, B, Ivashina, M, Konovalenko, O, Kutkin, A, Loose, G, Mulder, H, Ruiter, M, Smits, R, Tokarsky, P, Vermaas, N, Zakharenko, V, Zarka, P, and Ziemke, J
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Population, Frequency drift, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Spectral line, Radio telescope, stars: neutron, Pulsar, 0103 physical sciences, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, education.field_of_study, Scintillation, Line-of-sight, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astronomy and Astrophysics, Interstellar medium, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: PSR B0950+08 is a bright non-recycled pulsar whose single-pulse fluence variability is reportedly large. Based on observations at two widely separated frequencies, 55 MHz (NenuFAR) and 1.4 GHz (Westerbork Synthesis Radio Telescope), we review the properties of these single pulses. We conclude that they are more similar to ordinary pulses of radio emission than to a special kind of short and bright Giant Pulses, observed from only a handful of pulsars. We argue that temporal variation of properties of interstellar medium along the line of sight to this nearby pulsar, namely the fluctuating size of decorrelation bandwidth of diffractive scintillation makes important contribution to observed single-pulse fluence variability. We further present interesting structures in the low-frequency single-pulse spectra that resemble the "sad trombones" seen in Fast Radio Bursts (FRBs); although for PSR B0950+08 the upward frequency drift is also routinely present. We explain these spectral features with radius-to-frequency mapping, similar to the model developed by Wang et al. (2019) for FRBs. Finally, we speculate that microsecond-scale fluence variability of the general pulsar population remains poorly known, and that its further study may bring important clues about the nature of FRBs., Accepted by A&A. This version includes a number of minor corrections, including corrected FRB luminosities on the time-luminosity phase-space plot for radio pulses from neutron stars and repeating FRBs
Published: 2022

23. Sub-arcsecond imaging with the International LOFAR Telescope I. Foundational calibration strategy and pipeline

Author: Martin J. Hardcastle, H. Paas, Matthias Hoeft, J. Moldon, R. Pizzo, Arthur Corstanje, A. Kappes, S. Mooney, John McKean, Gottfried Mann, Pietro Zucca, Harvey Butcher, M. Pandey-Pommier, Joseph R. Callingham, A. Nelles, S. Duscha, Marco Iacobelli, Aleksander Shulevski, V. N. Pandey, Ph. Zarka, Annalisa Bonafede, S. Badole, M. Ruiter, Ashish Asgekar, Hanna Rothkaehl, M. P. van Haarlem, P. Kukreti, Wolfgang Reich, Michel Tagger, J. M. Anderson, Marian Soida, A. H. W. M. Coolen, Judith H. Croston, Olaf Wucknitz, Neal Jackson, Heino Falcke, W. N. Brouw, Jochen Eislöffel, Philip Best, A. Drabent, F. Sweijen, F. de Gasperin, Dominik J. Schwarz, Cyril Tasse, J. B. R. Oonk, J. M. Griessmeier, Benedetta Ciardi, S. Damstra, A. J. van der Horst, Stefan J. Wijnholds, C. Groeneveld, E. Jütte, D. Engels, I. M. Avruch, Ralph A. M. J. Wijers, Léon V. E. Koopmans, Timothy W. Shimwell, Emanuela Orru, Andrzej Krankowski, R. J. van Weeren, Leah K. Morabito, A. W. Gunst, I. van Bemmel, D. Venkattu, Mark J. Bentum, Adam T. Deller, Christian Vocks, George K. Miley, John Conway, M. A. Garrett, M. Bondi, Matthias Kadler, E. Bonnassieux, H. J. A. Röttgering, API Other Research (FNWI), High Energy Astrophys. & Astropart. Phys (API, FNWI), 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, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Université Paris sciences et lettres (PSL)-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), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), European Commission, European Research Council, Ministerio de Ciencia e Innovación (España), Science and Technology Facilities Council (UK), Astronomy, and Kapteyn Astronomical Institute
Subjects: Astronomy, Pipeline (computing), active, Field of view, Astrophysics, 01 natural sciences, law.invention, high angular resolution, radiation mechanisms, law, galaxies, active, galaxies, 010303 astronomy & astrophysics, media_common, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrometry, Interferometry, Astrophysics - Instrumentation and Methods for Astrophysics, high angular resolution, jets, active [Galaxies], media_common.quotation_subject, galaxies: active, FOS: Physical sciences, Telescope, 0103 physical sciences, Calibration, Instrumentation and Methods for Astrophysics (astro-ph.IM), Remote sensing, non-thermal [Radiation mechanisms], non-thermal radiation, 010308 nuclear & particles physics, techniques: high angular resolution, active galaxies, Astronomy and Astrophysics, LOFAR, radiation mechanisms: non-thermal, galaxies: jets, Astrophysics - Astrophysics of Galaxies, high angular resolution [Techniques], non-thermal, radiation mechanisms, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), non-thermal, galaxies, jets, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies, jets [Galaxies], techniques, jets of galaxies
Abstract: Full list of authors: Morabito, L. K.; Jackson, N. J.; Mooney, S.; Sweijen, F.; Badole, S.; Kukreti, P.; Venkattu, D.; Groeneveld, C.; Kappes, A.; Bonnassieux, E.; Drabent, A.; Iacobelli, M.; Croston, J. H.; Best, P. N.; Bondi, M.; Callingham, J. R.; Conway, J. E.; Deller, A. T.; Hardcastle, M. J.; McKean, J. P.; Miley, G. K.; Moldon, J.; Röttgering, H. J. A.; Tasse, C.; Shimwell, T. W.; van Weeren, R. J.; Anderson, J. M.; Asgekar, A.; Avruch, I. M.; van Bemmel, I. M.; Bentum, M. J.; Bonafede, A.; Brouw, W. N.; Butcher, H. R.; Ciardi, B.; Corstanje, A.; Coolen, A.; Damstra, S.; de Gasperin, F.; Duscha, S.; Eislöffel, J.; Engels, D.; Falcke, H.; Garrett, M. A.; Griessmeier, J.; Gunst, A. W.; van Haarlem, M. P.; Hoeft, M.; van der Horst, A. J.; Jütte, E.; Kadler, M.; Koopmans, L. V. E.; Krankowski, A.; Mann, G.; Nelles, A.; Oonk, J. B. R.; Orru, E.; Paas, H.; Pandey, V. N.; Pizzo, R. F.; Pandey-Pommier, M.; Reich, W.; Rothkaehl, H.; Ruiter, M.; Schwarz, D. J.; Shulevski, A.; Soida, M.; Tagger, M.; Vocks, C.; Wijers, R. A. M. J.; Wijnholds, S. J.; Wucknitz, O.; Zarka, P.; Zucca, P., The International LOFAR Telescope is an interferometer with stations spread across Europe. With baselines of up to ~2000 km, LOFAR has the unique capability of achieving sub-arcsecond resolution at frequencies below 200 MHz. However, it is technically and logistically challenging to process LOFAR data at this resolution. To date only a handful of publications have exploited this capability. Here we present a calibration strategy that builds on previous high-resolution work with LOFAR. It is implemented in a pipeline using mostly dedicated LOFAR software tools and the same processing framework as the LOFAR Two-metre Sky Survey (LoTSS). We give an overview of the calibration strategy and discuss the special challenges inherent to enacting high-resolution imaging with LOFAR, and describe the pipeline, which is publicly available, in detail. We demonstrate the calibration strategy by using the pipeline on P205+55, a typical LoTSS pointing with an 8 h observation and 13 international stations. We perform in-field delay calibration, solution referencing to other calibrators in the field, self-calibration of these calibrators, and imaging of example directions of interest in the field. We find that for this specific field and these ionospheric conditions, dispersive delay solutions can be transferred between calibrators up to ~1.5° away, while phase solution transferral works well over ~1°. We also demonstrate a check of the astrometry and flux density scale with the in-field delay calibrator source. Imaging in 17 directions, we find the restoring beam is typically ~0.3′′ ×0.2′′ although this varies slightly over the entire 5 deg2 field of view. We find we can achieve ~80–300 μJy bm−1 image rms noise, which is dependent on the distance from the phase centre; typical values are ~90 μJy bm−1 for the 8 h observation with 48 MHz of bandwidth. Seventy percent of processed sources are detected, and from this we estimate that we should be able to image roughly 900 sources per LoTSS pointing. This equates to ~ 3 million sources in the northern sky, which LoTSS will entirely cover in the next several years. Future optimisation of the calibration strategy for efficient post-processing of LoTSS at high resolution makes this estimate a lower limit. © ESO 2022., This work made use of the Dutch national e-infrastructure with the support of the SURF Cooperative using grant no. EINF-262 LKM is grateful for support from the Medical Research Council (grant MR/T042842/1). S.M. acknowledges support from the Governmentof Ireland Postgraduate Scholarship Programme. E.B. acknowledges support from the ERC-ERG grant DRANOEL, n.714245. A.D. acknowledges support by the BMBF Verbundforschung under the grant 052020. J.H.C. acknowledges support from the UK Science and Technology Facilities Council (ST/R000794/1). P.N.B. is grateful for support from the UK STFC via grant ST/R000972/1. J.R.C. thanks the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) for support via the Talent Programme Veni grant. M.J.H. acknowledges support from the UK Science and Technology Facilities Council (ST/R000905/1). J.P.M. acknowledges support from the NetherlandsOrganization for Scientific Research (NWO, project number 629.001.023) and the Chinese Academy of Sciences (CAS, project number 114A11KYSB20170054). J.M. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísicade Andalucía (SEV-2017-0709) and from the grant RTI2018-096228-B-C31 (MICIU/FEDER, EU). R.J.v.W. acknowledges support from the ERC Starting Grant ClusterWeb 804208. D.J.S. acknowledges support by the GermanFederal Ministry for Science and Research BMBF-Verbundforschungsprojekt D-LOFAR 2.0 (grant numbers 05A20PB1). LOFAR (van Haarlem et al. 2013) is the Low Frequency Array designed and constructed by ASTRON. It has observing, data processing, and data storage facilities in several countries, that are owned by various parties (each with their own funding sources), and that are collectively operated by the ILT foundation under a joint scientific policy. The ILT resources have benefitted from the following recent major funding sources: CNRS-INSU, Observatoire de Paris and Université d’Orléans, France; BMBF, MIWF-NRW, MPG, Germany; Science Foundation Ireland (SFI), Department of Business, Enterprise and Innovation (DBEI), Ireland; NWO, The Netherlands; The Science and Technology Facilities Council, UK; Ministry of Science and Higher Education, Poland.
Published: 2022

24. Investigating Mercury's Environment with the Two-Spacecraft BepiColombo Mission

Author: Oleg Korablev, M. Fujimoto, Léa Griton, Cesare Grava, Masafumi Hirahara, Hirotsugu Kojima, S. Barabash, Wolfgang Baumjohann, A. Martindale, Chuanfei Dong, François Leblanc, Chris Carr, S. T. Lindsay, Yasumasa Kasaba, M. Kobayashi, Herbert Lichtenegger, Philippe-A. Bourdin, Karri Muinonen, J. S. Oliveira, Jan-Erik Wahlund, Ferdinand Plaschke, Christina Plainaki, S. M. P. McKenna-Lawlor, Dominique Delcourt, Eric Quémerais, Xianzhe Jia, Dusan Odstrcil, James A. Slavin, V. Mangano, M. G. Pelizzo, Benoit Langlais, Joe Zender, Emma J. Bunce, Ichiro Yoshikawa, Peter Wurz, Stavro Ivanovski, Stefano Massetti, George C. Ho, Y. Saito, Juhani Huovelin, Suzanne M. Imber, Sae Aizawa, Alessandro Mura, Jim M. Raines, Ayako Matsuoka, F. Sahraoui, Karl-Heinz Glassmeier, Pierre Henri, Rami Vainio, Matthew K. James, Rosemary M. Killen, Stefano Orsini, Shahab Fatemi, Tomas Karlsson, Monica Laurenza, Esa Kallio, Christoph Lhotka, Michiko Morooka, Johannes Benkhoff, David A. Rothery, Yasuhito Narita, Michel Moncuquet, Anna Milillo, Alexey A. Berezhnoy, Satoshi Yagitani, Adam Masters, F. Califano, Manuel Grande, Stefano Livi, Daniel Heyner, Emilia Kilpua, G. Murakami, Jan Deca, S. de la Fuente, R. Moissl, Bernard V. Jackson, Kanako Seki, N. André, M. Dósa, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Wigner Research Centre for Physics [Budapest], Hungarian Academy of Sciences (MTA), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Space Research Centre [Leicester], University of Leicester, Department of Space and Plasma Physics [Stockholm], KTH School of Electrical Engineering, Royal Institute of Technology [Stockholm] (KTH )-Royal Institute of Technology [Stockholm] (KTH ), NASA Goddard Space Flight Center (GSFC), Space Technology Ireland Limited, Department of Climate and Space Sciences and Engineering (CLaSP), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Sternberg Astronomical Institute [Moscow], Lomonosov Moscow State University (MSU), University of Pisa - Università di Pisa, University of Colorado [Boulder], European Space Astronomy Centre (ESAC), Princeton Plasma Physics Laboratory (PPPL), Princeton University, Department of Astrophysical Sciences [Princeton], Southwest Research Institute [San Antonio] (SwRI), Swedish Institute of Space Physics [Kiruna] (IRF), 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), INAF - Osservatorio Astronomico di Trieste (OAT), University of California [San Diego] (UC San Diego), University of California (UC), Department of Electronics and Nanoengineering [Espoo], School of Electrical Engineering [Aalto Univ], Aalto University-Aalto University, Planetary Plasma and Atmospheric Research Center [Sendai] (PPARC), Tohoku University [Sendai], Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Planetary Exploration Research Center [Chiba] (PERC), Chiba Institute of Technology (CIT), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Blackett Laboratory, Imperial College London, Swedish Institute of Space Physics [Uppsala] (IRF), Institute of Physics [Graz], Karl-Franzens-Universität Graz, Centro de Investigação da Terra e do Espaço da UC (CITEUC), Universidade de Coimbra [Coimbra], CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Italian Space Agency, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Planetary Science [Tokyo], Graduate School of Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), Space Research Laboratory [Turku] (SRL), Department of Physics and Astronomy [Turku], University of Turku-University of Turku, Physics Institute [Bern], University of Bern, Department of Physics [Imperial College London], Institute of Mathematical and Physical Sciences [Aberystwyth], University of Wales, Institute for Space-Earth Environmental Research [Nagoya] (ISEE), Nagoya University, Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Research Institute for Sustainable Humanosphere (RISH), Kyoto University, 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), Graduate School of the Natural Science and Technology [Kanazawa], Kanazawa University (KU), Department of Complexity Science and Engineering [Tokyo], The University of Tokyo (UTokyo), European Space Agency (ESA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), 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), University of California, University of Helsinki-University of Helsinki, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Karl-Franzens-Universität [Graz, Autriche], Consiglio Nazionale delle Ricerche [Roma] (CNR), Kyoto University [Kyoto], 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), The Royal Society, Science and Technology Facilities Council, INAF National Institute for Astrophysics, JAXA Institute of Space and Astronautical Science, European Space Research and Technology Centre, IRAP, Hungarian Academy of Sciences, Technical University of Braunschweig, Johns Hopkins Applied Physics Laboratory, University of Michigan, Ann Arbor, KTH Royal Institute of Technology, NASA Goddard Space Flight Center, Space Technology Ireland, Open University Milton Keynes, Austrian Academy of Sciences, Lomonosov Moscow State University, University of Pisa, University of Colorado Boulder, European Space Astronomy Centre, Princeton Plasma Physics Laboratory, Southwest Research Institute, Uppsala University, Université d'Orléans, Osservatorio Astronomico di Trieste, University of California San Diego, Department of Electronics and Nanoengineering, Tohoku University, University of Helsinki, Chiba Institute of Technology, Université de Nantes, Sorbonne Université, University of Graz, National Research Council of Italy, Agenzia Spaziale Italiana, The University of Tokyo, University of Turku, Aberystwyth University, Space Research Institute of the Russian Academy of Sciences, Université de Versailles Saint-Quentin-en-Yvelines, Kanazawa University, Aalto-yliopisto, and Aalto University
Subjects: 010504 meteorology & atmospheric sciences, Computer science, BepiColombo, chemistry.chemical_element, FOS: Physical sciences, Astronomy & Astrophysics, 01 natural sciences, Mercury’s environment, Fusion, plasma och rymdfysik, Interplanetary dust cloud, Astronomi, astrofysik och kosmologi, 0201 Astronomical and Space Sciences, 0103 physical sciences, Astronomy, Astrophysics and Cosmology, Exosphere, Magnetosphere, Aerospace engineering, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 0105 earth and related environmental sciences, Scientific instrument, Earth and Planetary Astrophysics (astro-ph.EP), Spacecraft, business.industry, 520 Astronomy, Astronomy and Astrophysics, 620 Engineering, Fusion, Plasma and Space Physics, Mercury (element), Solar wind, Planetary science, chemistry, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Mercury's environment, Mercury’s environment · Magnetosphere · Exosphere · BepiColombo, Astrophysics - Instrumentation and Methods for Astrophysics, business, Astrophysics - Earth and Planetary Astrophysics
Abstract: The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MESSENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury's environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors., Comment: 78 pages, 14 figures, published
Published: 2022
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25. A comparative analysis of pulse time-of-arrival creation methods

Author: J. Wang, G. M. Shaifullah, J. P. W. Verbiest, C. Tiburzi, D. J. Champion, I. Cognard, M. Gaikwad, E. Graikou, L. Guillemot, H. Hu, R. Karuppusamy, M. J. Keith, M. Kramer, Y. Liu, A. G. Lyne, M. B. Mickaliger, B. W. Stappers, G. Theureau, Wang, J, Shaifullah, G, Verbiest, J, Tiburzi, C, Champion, D, Cognard, I, Gaikwad, M, Graikou, E, Guillemot, L, Hu, H, Karuppusamy, R, Keith, M, Kramer, M, Liu, Y, Lyne, A, Mickaliger, M, Stappers, B, Theureau, G, 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), 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), Laboratoire Univers et Théories (LUTH (UMR_8102)), 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: 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy and Astrophysics, 01 natural sciences, Pulsars: general, Computer Science::Systems and Control, Space and Planetary Science, Physics::Space Physics, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Methods: data analysi
Abstract: Context.Extracting precise pulse times of arrival (TOAs) and their uncertainties is the first and most fundamental step in high-precision pulsar timing. In the classical method, TOAs are derived from total intensity pulse profiles of pulsars via cross-correlation with an idealised 1D template of that profile. While a number of results have been presented in the literature that rely on the ever increasing sensitivity of these pulsar timing experiments, there is no consensus on the most reliable methods for creating TOAs, and, more importantly, on the associated TOA uncertainties for each scheme.Aims.We present a comprehensive comparison of TOA determination practices. We focus on creating timing templates, TOA determination methods, and the most useful TOA bandwidth. The aim is to present a possible approach towards TOA optimisation, the (partial) identification of an optimal TOA-creation scheme, and the demonstration of optimisation differences between pulsars and data sets.Methods.We compared the values of data-derived template profiles with analytic profiles and evaluated the three most commonly used template-matching methods. Finally, we studied the relation between timing precision and TOA bandwidth to identify any potential breaks in this relation. As a practical demonstration, we applied our selected methods to European Pulsar Timing Array data on three test pulsars, PSRs J0218+4232, J1713+0747, and J2145−0750.Results.Our demonstration shows that data-derived and smoothed templates are typically preferred to some more commonly applied alternatives. The template-matching method called Fourier domain with Markov chain Monte Carlo is generally superior to or competitive with other methods. While the optimal TOA bandwidth is strongly dependent on pulsar brightness, telescope sensitivity, and scintillation properties, some significant frequency averaging seems required for the data we investigated.
Published: 2022

26. An innovative kinetic model allowing insight in the moderate temperature chemical vapor deposition of silicon oxynitride films from tris(dimethylsilyl)amine

Author: Konstantina Christina Topka, Paris Papavasileiou, Babacar Diallo, Tryfon Tsiros, Laura Decosterd, Brigitte Caussat, Marie-Joëlle Menu, Diane Samélor, Constantin Vahlas, Hugues Vergnes, François Senocq, Nadia Pellerin, Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Laboratoire de Génie Chimique (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Université d'Orléans (UO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE08-0056,HEALTHYGLASS,Surfaces de verre performantes et durables pour la pharmacie(2017), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Laboratoire de Génie Civil (LGC), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)
Subjects: Experimental validation, Silicon oxynitride, Materials science, Silicon, General Chemical Engineering, Matériaux, chemistry.chemical_element, 02 engineering and technology, Chemical vapor deposition, Computational fluid dynamics, 01 natural sciences, Chemical reaction, Industrial and Manufacturing Engineering, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, Phase (matter), 0103 physical sciences, Environmental Chemistry, Molecule, Deposition (phase transition), Génie chimique, Thin film, Génie des procédés, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, Kinetic model, 021001 nanoscience & nanotechnology, Silanamine precursor, chemistry, Chemical engineering, 0210 nano-technology
Abstract: International audience; An apparent kinetic model is developed for a novel chemical vapor deposition (CVD) process of silicon oxynitride (SiO x N y) films from tris(dimethylsilyl)amine (TDMSA) and O 2 , operating at moderate temperature (600-650 • C) and at atmospheric pressure. The definition of reaction pathways and the extraction of kinetic information is based on recently reported results of the gas phase composition, complemented by solid phase characteristics obtained by spectroscopic ellipsometry (SE) and ion beam analyses (IBA). Incorporation of carbon (up to 20 at. %) is considered alongside nitrogen (up to 25 at.%) for variable O 2 flow rates (0.3-1.2 sccm). This combined gasand solid-phase analysis is utilized to identify the main gaseous species and provide insight into the deposition mechanism. A silicon-and a nitrogen-centered radical intermediates are considered as the primary species of the mechanism, based on evidence from gas phase characterizations. A third, fictitious, nitrogen-and carboncontaining molecule is also conceptualized to account for carbon incorporation. Eight chemical reactions are defined alongside their respective kinetic parameters and are implemented in the ANSYS® FLUENT® computational fluid dynamics (CFD) code. Upon validation, the model allows for the successful prediction of local deposition rates and SiO x N y film composition containing non-negligible carbon, marking it as the first kinetic model able to represent the main chemical mechanisms involved in the CVD of a four-component material. The reported combined approach could be applied to other existing or new CVD chemistries forming multicomponent thin films, favoring their implementation in original applications.
Published: 2022

27. A Case for Electron-Astrophysics

Author: Satoshi Kasahara, Julia E. Stawarz, Thierry Dudok de Wit, Daniel Told, Yuri V. Khotyaintsev, Christopher S. Reynolds, Stepan Stverak, Bennett A. Maruca, David Burgess, Milan Maksimovic, Jiansen He, Owen Roberts, Joachim Saur, Robert T. Wicks, Benoit Lavraud, Shinji Saito, Olga Alexandrova, Luca Franci, Sergio Servidio, Ferdinand Plaschke, Katja Klein, Raffaella D'Amicis, Pierre Henri, Chadi S. Salem, Christopher H. K. Chen, Johan De Keyser, Daniel Verscharen, Fouad Sahraoui, Roberto Bruno, Stefaan Poedts, Observatoire de Paris - Site de Paris (OP), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), 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)-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, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-École polytechnique (X)-Sorbonne Universités-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), University of New Hampshire (UNH), University of Northumbria at Newcastle [United Kingdom], 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), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Queen Mary University of London (QMUL), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), School of Earth and Space Sciences [Beijing], Peking University [Beijing], Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), The University of Tokyo (UTokyo), Institutet för Rymdfysik, University of Arizona, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Bartol Research Institute, University of Delaware [Newark], Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Centre for Mathematical Plasma-Astrophysics [Leuven] (CmPA), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Maria Curie-Sklodowska University (UMCS), Institute of Astronomy, University of Cambridge, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), National Institute of Information and Communications Technology [Tokyo, Japan] (NICT), University of California [Berkeley], University of California, Institut für Geophysik und Meteorologie [Köln], Universität zu Köln, Università della Calabria [Arcavacata di Rende] (Unical), Department of Physics [Imperial College London], Imperial College London, Czech Academy of Sciences [Prague] (CAS), Max Planck Institute for Plasma physics (IPP-MPG), Max-Planck-Gesellschaft, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Verscharen, Daniel [0000-0002-0497-1096], and Apollo - University of Cambridge Repository
Subjects: Field (physics), F300, FOS: Physical sciences, Electrons, F500, Electron, 7. Clean energy, 01 natural sciences, F900, Physics - Space Physics, Voyage 2050, Physics::Plasma Physics, 0103 physical sciences, Thermal, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Plasma, space missions, Dissipation, plasma astrophysics, Physics - Plasma Physics, Space Physics (physics.space-ph), [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Computational physics, Magnetic field, Plasma Physics (physics.plasm-ph), space plasma, Solar wind, Astrophysics - Solar and Stellar Astrophysics, solar wind, Space and Planetary Science, Physics::Space Physics, Astrophysical plasma, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: A grand-challenge problem at the forefront of physics is to understand how energy is transported and transformed in plasmas. This fundamental research priority encapsulates the conversion of plasma-flow and electromagnetic energies into particle energy, either as heat or some other form of energisation. The smallest characteristic scales, at which electron dynamics determines the plasma behaviour, are the next frontier in space and astrophysical plasma research. The analysis of astrophysical processes at these scales lies at the heart of the field of electron-astrophysics. Electron scales are the ultimate bottleneck for dissipation of plasma turbulence, which is a fundamental process not understood in the electron-kinetic regime. Since electrons are the most numerous and most mobile plasma species in fully ionised plasmas and are strongly guided by the magnetic field, their thermal properties couple very efficiently to global plasma dynamics and thermodynamics., Comment: White Paper for the Voyage 2050 Long-Term Plan in the ESA Science Programme; 27 pages
Published: 2022

28. Residence Time Prediction of Type 1 and 2 Kinase Inhibitors from Unbinding Simulations

Author: Samia Aci-Sèche, Pascal Bonnet, A. Braka, Norbert Garnier, Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie Organique et Analytique (ICOA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), and Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Institut National de la Santé et de la Recherche Médicale (INSERM)
Subjects: General Chemical Engineering, Kinetics, Molecular Dynamics Simulation, Library and Information Sciences, Ligands, 01 natural sciences, Molecular dynamics, In vivo, 0103 physical sciences, Binding site, Protein Kinase Inhibitors, Residence time (statistics), 010304 chemical physics, Drug discovery, Chemistry, Ligand, General Chemistry, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], 0104 chemical sciences, Computer Science Applications, 010404 medicinal & biomolecular chemistry, Thermodynamics, Probability distribution, Biological system, [CHIM.CHEM]Chemical Sciences/Cheminformatics, Protein Binding
Abstract: International audience; In the early stage of a drug discovery process, the selection and optimization of a ligand is mainly based on equilibrium thermodynamic constants such as KD or IC50 values, which are representatives of the affinity of the compound for its target. However, these criteria are not able to correctly evaluate the efficacy of compounds in vivo and result in many failures of compound development during phase II of clinical trials. Residence time (RT) is an important parameter associated to an in vivo drug’s safety and efficacy. The determination or modulation of kinetic rates correlated to RT may be performed to identify the best drug candidates in the early stages of a drug design project. For this purpose, a number of experimental methodologies were developed but remain costly in both time and money. Herein, we developed a novel protocol based on biased molecular dynamics simulations and transition-state theory in order to predict relative ligand kinetic rates and relative RTs of a series of compounds. First, we have repeatedly simulated the unbinding process of the ligand from its binding site to the outside of the target. Next, we sample the conformational space along the determined unbinding paths to allow relevant statistical distributions of the system. The free energy profiles associated to these distributions are then computed and used to predict the kinetics parameters. The studied set was composed of eight ligands with fast, intermediate, and slow dissociation rates and binding to the active and inactive states of p38α protein kinase. The proposed method provides an excellent correlation between the predicted values and the experimentally measured kinetic rates, in addition to a detailed characterization of the kinetic paths at the atomic level.
Published: 2019

29. An asymptotic finite plane deformation analysis of the elastostatic fields at a crack tip in the framework of hyperelastic, isotropic, and nearly incompressible neo-Hookean materials under mode-I loading

Author: Hocine Bechir, Arnaud Frachon, Mounir Methia, Nourredine Aït Hocine, Mécanique des Matériaux et Procédés (MMP), Laboratoire de Mécanique Gabriel Lamé (LaMé), Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)
Subjects: Physics, Asymptotic analysis, Deformation (mechanics), Cauchy stress tensor, Mechanical Engineering, Constitutive equation, Mathematical analysis, Computational Mechanics, 02 engineering and technology, 01 natural sciences, Finite element method, 010305 fluids & plasmas, Stress (mechanics), 020303 mechanical engineering & transports, 0203 mechanical engineering, Hyperelastic material, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], 0103 physical sciences, Asymptotic expansion, ComputingMilieux_MISCELLANEOUS
Abstract: In this work, stress and displacement fields were computed around a crack tip in the case of nearly incompressible and isotropic neo-Hookean material. The constitutive equation was linearized, so that the Cauchy stress tensor could be written as a sum of two components: the linear response in term of elastic Hooke’s law and the nonlinear one. Based on this decomposition, an asymptotic analysis has been developed, the fields of linear elastic fracture mechanics (LEFM-theory) are the zero-order terms of the asymptotic expansion. The validity of the proposed theory has been checked in the case of a mode-I crack problem. A numerical model was constructed using a finite element method. It has shown that the computed fields arising from this theory are qualitatively in agreement with those of the finite element simulations.
Published: 2019

30. Highly structured slow solar wind emerging from an equatorial coronal hole

Author: Vladimir Krasnoselskikh, Säm Krucker, C. Fong, D. J. McComas, James A. Klimchuk, Tai Phan, Michel Moncuquet, N.-E. Raouafi, Marco Velli, Anthony W. Case, C. C. Chaston, Justin C. Kasper, John W. Bonnell, Melvyn L. Goldstein, David Burgess, John R. Wygant, Gregory G. Howes, Christopher H. K. Chen, Trevor A. Bowen, David Stansby, Robert E. Ergun, R. Laker, Samuel T. Badman, Stuart D. Bale, T. Dudok de Wit, F. S. Mozer, Robert J. MacDowall, Keith Goetz, David M. Malaspina, Nicole Meyer-Vernet, Jonathan Eastwood, Davin Larson, Katherine Goodrich, Michael L. Stevens, Adam Szabo, William M. Farrell, Marc Pulupa, Benjamin D. G. Chandran, Kelly E. Korreck, Paul J. Kellogg, Milan Maksimovic, James Drake, J. C. Martínez-Oliveros, Timothy S. Horbury, Cynthia A Cattell, T. Woolley, Chadi Salem, Peter Harvey, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Astronomy Unit [London] (AU), Queen Mary University of London (QMUL), School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, University of California, 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), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Imperial College London, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, 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), Princeton University, NASA Ames Research Center (ARC), Smithsonian Astrophysical Observatory, Smithsonian Institution, The Leverhulme Trust, and Science and Technology Facilities Council (STFC)
Subjects: Solar minimum, 010504 meteorology & atmospheric sciences, General Science & Technology, Astrophysics::High Energy Astrophysical Phenomena, WAVES, Astronomical unit, Coronal hole, Solar radius, Astrophysics, 01 natural sciences, INTERPLANETARY, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, MISSION, 0105 earth and related environmental sciences, Physics, Science & Technology, Multidisciplinary, MAGNETIC-FIELD, Ecliptic, Solar physics, Multidisciplinary Sciences, MODEL, Solar wind, [SDU]Sciences of the Universe [physics], 13. Climate action, Physics::Space Physics, Science & Technology - Other Topics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Interplanetary spaceflight
Abstract: During the solar minimum, when the Sun is at its least active, the solar wind1,2 is observed at high latitudes as a predominantly fast (more than 500 kilometres per second), highly Alfvenic rarefied stream of plasma originating from deep within coronal holes. Closer to the ecliptic plane, the solar wind is interspersed with a more variable slow wind3 of less than 500 kilometres per second. The precise origins of the slow wind streams are less certain4; theories and observations suggest that they may originate at the tips of helmet streamers5,6, from interchange reconnection near coronal hole boundaries7,8, or within coronal holes with highly diverging magnetic fields9,10. The heating mechanism required to drive the solar wind is also unresolved, although candidate mechanisms include Alfven-wave turbulence11,12, heating by reconnection in nanoflares13, ion cyclotron wave heating14 and acceleration by thermal gradients1. At a distance of one astronomical unit, the wind is mixed and evolved, and therefore much of the diagnostic structure of these sources and processes has been lost. Here we present observations from the Parker Solar Probe15 at 36 to 54 solar radii that show evidence of slow Alfvenic solar wind emerging from a small equatorial coronal hole. The measured magnetic field exhibits patches of large, intermittent reversals that are associated with jets of plasma and enhanced Poynting flux and that are interspersed in a smoother and less turbulent flow with a near-radial magnetic field. Furthermore, plasma-wave measurements suggest the existence of electron and ion velocity-space micro-instabilities10,16 that are associated with plasma heating and thermalization processes. Our measurements suggest that there is an impulsive mechanism associated with solar-wind energization and that micro-instabilities play a part in heating, and we provide evidence that low-latitude coronal holes are a key source of the slow solar wind. Measurements from the Parker Solar Probe show that slow solar wind near the Sun’s equator originates in coronal holes.
Published: 2019

31. Low Frequency (f < 200 Hz) Polar Plasmaspheric Hiss: Coherent and Intense

Author: Pierre Henri, Barbara J. Falkowski, Jolene S. Pickett, Sang A. Park, Rajkumar Hajra, Jacob Bortnik, Abhijit Sen, Gurbax S. Lakhina, Michell Parrot, Bruce T. Tsurutani, Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, University of California [Berkeley], University of California, Glendale Community College, University of California [Los Angeles] (UCLA), Indian Institute of Geomagnetism [Navi Mumbai, India] (IIG), Institute for plasma research, Institute for Plasma Research, Department of Physics and Astronomy [Ames, Iowa], Iowa State University (ISU), National Atmospheric Research Laboratory [Tirupathi] (NARL), Indian Space Research Organisation (ISRO), 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, and 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)
Subjects: Physics, Hiss, 010504 meteorology & atmospheric sciences, Astrophysics, Low frequency, 01 natural sciences, Geophysics, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Physics::Space Physics, 0103 physical sciences, Polar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; Low Frequency (LF) ~22 Hz to 200 Hz plasmaspheric hiss was studied using a year of Polar plasma wave data occurring during solar cycle minimum. The waves are found to be most intense in the noon and early dusk sectors. When only the most intense LF (ILF) hiss were examined, they are found to be substorm dependent and most prominent in the noon sector. The noon sector ILF waves were also determined to be independent of solar wind ram pressure. The ILF hiss intensity are independent of magnetic latitude. ILF hiss is found to be highly coherent in nature. ILF hiss propagates at all angles relative to the ambient magnetic field. Circular, elliptical and linear/highly elliptically polarized hiss have been detected, with elliptical polarization the dominant characteristic. A case of linear polarized ILF hiss that occurred deep in the plasmasphere during geomagnetic quiet was noted. The waveforms and polarizations of ILF hiss are similar to those of intense high frequency (IHF) hiss.We propose the hypothesis that ~10‐100 keV substorm injected electrons gradient drift to dayside minimum B pockets close to the magnetopause to generate LF chorus. The closeness of this chorus to low altitude entry points into the plasmasphere will minimize wave damping and allow intense noon‐sector ILF hiss. The coherency of ILF hiss leads the authors to predict energetic electron precipitation into the midlatitude ionosphere and the electron slot formation during substorms. Several means of testing the above hypotheses are discussed.
Published: 2019

32. Radio detection of cosmic rays in [1.7–3.7] MHz: The EXTASIS experiment

Author: Richard Dallier, Lilian Martin, Alain Lecacheux, Benoît Revenu, D. García-Fernández, Antony Escudie, Didier Charrier, 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), 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, 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), Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-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 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: air, FOS: Physical sciences, Cosmic ray, Scintillator, 01 natural sciences, Sudden death, Signal, Observatory, Electric field, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation and Methods for Astrophysics (astro-ph.IM), electric field: high, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, radio wave, showers: atmosphere, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, observatory, cosmic radiation, Pulse-amplitude modulation, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Radio wave
Abstract: Since 2003, significant efforts have been devoted to the understanding of the radio emission of extensive air showers above 20 MHz. Despite some studies led until the early nineties, the band available below 20 MHz has remained unused for 20 years. However, it has been claimed by some pioneering experiments that extensive air showers emit a strong electric field in this band and that there is evidence of a large increase of the radio pulse amplitude with decreasing frequencies. The EXTASIS experiment, located within the Nan\c{c}ay Radioastronomy Observatory and supported by the scintillator array and the autonomous radio stations of the CODALEMA experiment, aims to re-investigate the low-frequency band, and especially to study the so-called "sudden death" contribution, the expected electric field radiated by the shower front when hitting ground level. In this work, we present the instrumental setup of the EXTASIS experiment composed of~$7$ low-frequency antennas operating in [1.7-3.7] MHz and covering approximately \SI{1}{\kilo\metre\squared}. We report the observation of~$18$ air showers detected in coincidence in the three instruments, and estimate a detection threshold of \SI{23\pm4}{\micro\volt\per\metre} from comparisons with detailed SELFAS3 simulations. We also report a strong correlation of the low-frequency signal observation with the atmospheric electric field., Comment: Submitted to Astroparticle Physics, corresponding author: Antony Escudie
Published: 2019

33. The Heisenberg limit at cosmological scales

Author: Alessandro D. A. M. Spallicci, Micol Benetti, Salvatore Capozziello, 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), Spallicci Di Filottrano, Alessandro D.A.M., Spallicci, Alessandro D. A. M., Benetti, Micol, and Capozziello, Salvatore
Subjects: [SDU] Sciences of the Universe [physics], [PHYS]Physics [physics], General Physics (physics.gen-ph), Physics - General Physics, 010308 nuclear & particles physics, [SDU]Sciences of the Universe [physics], 0103 physical sciences, FOS: Physical sciences, General Physics and Astronomy, 16. Peace & justice, 010303 astronomy & astrophysics, 01 natural sciences, [PHYS] Physics [physics]
Abstract: For an observation time {equal to} the universe age, the Heisenberg principle fixes the value of the smallest measurable mass at $m_{\rm H}=1.35 \times 10^{-69}$ kg and prevents to probe the masslessness for any particle using a balance. The corresponding reduced Compton length to $m_{\rm H}$ is $\lambdabar_{\rm H}$, and represents the length limit beyond which masslessness cannot be proved using a metre ruler. In turns, $\lambdabar_{\rm H}$ is equated to the luminosity distance $d_{\rm H}$ which corresponds to a red shift $z_{\rm H}$. When using the Concordance-Model parameters, we get $d_{\rm H} = 8.4$ Gpc and $z_{\rm H}=1.3$. Remarkably, $d_{\rm H}$ falls quite short to the radius of the {\it observable} universe. According to this result, tensions in cosmological parameters could be nothing else but due to comparing data inside and beyond $z_{\rm H}$. Finally, in terms of quantum quantities, the expansion constant $H_0$ reveals to be one order of magnitude above the smallest measurable energy, divided by the Planck constant, A different view on the Hubble tension. To appear in final form on Foundations of Physics by Springer, as follow-on of Capozziello S., Benetti M., Spallicci A.D.A.M., 2020, Found. Phys., 50, 893
Published: 2021

34. Quantum states and their back-reacted geometries in 2d dilaton gravity

Author: Yohan Potaux, Debajyoti Sarkar, Sergey N. Solodukhin, Institut Denis Poisson (IDP), Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO), and Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO)
Subjects: High Energy Physics - Theory, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, General Relativity and Quantum Cosmology, High Energy Physics::Theory, High Energy Physics - Theory (hep-th), 0103 physical sciences, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], horizon: geometry, gravitation: dilaton, geometry: semiclassical, black hole: entropy, 010306 general physics, dimension: 2
Abstract: Within the Russo-Susskind-Thorlacius (RST) two-dimensional model that includes a scalar (dilaton) field we address the important question of how the classical black hole geometry is modified in a semiclassical gravitational theory. It is the principle goal of this paper to analyze what is the back-reacted geometry that corresponds to a given quantum state. The story is shown to be dramatically different for the Hartle-Hawking state (HH) and for the Boulware state. In the HH case the back-reacted geometry is a modification of the classical black hole metric that still has a smooth horizon with a regular curvature. On the other hand, for the Boulware state the classical horizon is replaced by a throat in which the $(tt)$ component of the metric (while non-zero) is extremely small. The value of the metric at the throat is bounded by the inverse of the classical black hole entropy. On the other side of the throat the spacetime is ended at a null singularity. More generally, we identify a family of quantum states and their respective back-reacted geometries. We also identify a certain duality in the space of states. Finally, we study a hybrid set-up where both physical and non-physical fields, such as the ghosts, could be present. We suggest that it is natural to associate ghosts with the Boulware state, while the physical fields can be in any quantum state. In particular, if the physical fields are in the HH state, then the corresponding semiclassical geometry is horizonless. Depending on the balance between the number of physical fields and ghosts, it generically has a throat that may join with another asymptotically flat region on the other side of the throat., Comment: 38 pages, 7 figures. Version 2. Published version. Minor typos corrected
Published: 2021

35. Detection method for shock-waves in viscous flows

Author: Léo Kovacs, Pierre-Yves Passaggia, Nicolas Mazellier, Viviana Lago, Laboratoire pluridisciplinaire de recherche en ingénierie des systèmes, mécanique et énergétique (PRISME), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut des Sciences de l'Ingénierie et des Systèmes (INSIS), CAPRYSSES -anr-11-LAb-0006, and ANR-11-LABX-0006,CAPRYSSES,Cinétique chimique et Aérothermodynamique pour des Propulsions et des Systèmes Energétiques Propres(2011)
Subjects: supersonic rarefied flow, [PHYS]Physics [physics], Fluid Flow and Transfer Processes, Computational Mechanics, General Physics and Astronomy, boundary layer, 01 natural sciences, shock-waves, 010305 fluids & plasmas, [SPI]Engineering Sciences [physics], Mechanics of Materials, viscous flows, 0103 physical sciences, 010306 general physics
Abstract: International audience; Shock waves in viscous flows present thick and diffuse shock layers that merge with the boundary layer. These specific characteristics make detection and analysis difficult and inaccurate. To improve shock-wave detection, a method based on Fourier self-deconvolution (FSD) is presented in this paper. Test cases consider a concrete application with a test case obtained in a supersonic rarefied flow around a cylinder. In a first step, the method was validated with numerical flow fields calculated with the DS2V code based on a Monte Carlo algorithm. Then, the FSD method was applied to experimental flows operating at Mach 2 and Mach 4 in the low-density MARHy facility. The experimental flow fields were measured using the glow discharge technique, and shock-wave detection was validated against pressure profiles measured with a Pitot tube. The proposed method makes it possible to identify three characteristic zones of the shock: the shock foot, its centre and the maximum density zone, making it possible to deduce its thickness and obtain a precise estimation of the standoff distance. In addition to being completely non-intrusive, the method appears to be parameter free, robust and easy to implement.
Published: 2021

36. Searching for Gravitational Waves from Cosmological Phase Transitions with the NANOGrav 12.5-Year Dataset

Author: Arzoumanian, Zaven, Baker, Paul T., Blumer, Harsha, Becsy, Bence, Brazier, Adam, Brook, Paul R., Burke-Spolaor, Sarah, Charisi, Maria, Chatterjee, Shami, Chen, Siyuan, Cordes, James M., Cornish, Neil J., Crawford, Fronefield, Cromartie, H. Thankful, DeCesar, Megan E., Demorest, Paul B., Dolch, Timothy, Ellis, Justin A., Ferrara, Elizabeth C., Fiore, William, Fonseca, Emmanuel, Garver-Daniels, Nathan, Gentile, Peter A., Good, Deborah C., Hazboun, Jeffrey S., Holgado, A. Miguel, Islo, Kristina, Jennings, Ross J., Jones, Megan L., Kaiser, Andrew R., Kaplan, David L., Kelley, Luke Zoltan, Key, Joey Shapiro, Laal, Nima, Lam, Michael T., Lazio, T. Joseph W., Lee, Vincent S. H., Lorimer, Duncan R., Luo, Jing, Lynch, Ryan S., Madison, Dustin R., McLaughlin, Maura A., Mingarelli, Chiara M. F., Mitridate, Andrea, Ng, Cherry, Nice, David J., Pennucci, Timothy T., Pol, Nihan S., Ransom, Scott M., Ray, Paul S., Shapiro-Albert, Brent J., Siemens, Xavier, Simon, Joseph, Spiewak, Renée, Stairs, Ingrid H., Stinebring, Daniel R., Stovall, Kevin, Sun, Jerry P., Swiggum, Joseph K., Taylor, Stephen R., Turner, Jacob E., Vallisneri, Michele, Vigeland, Sarah J., Witt, Caitlin A., Zurek, Kathryn M., 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), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-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), and NANOGrav
Subjects: data analysis method, Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010308 nuclear & particles physics, scale: electroweak interaction, General Physics and Astronomy, FOS: Physical sciences, NANOGrav, critical phenomena, 01 natural sciences, bubble: nucleation, gravitational radiation detector, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), binary: coalescence, black hole: binary, [SDU]Sciences of the Universe [physics], gravitational radiation: emission, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, numerical calculations, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, pulsar
Abstract: We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5 year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black holes mergers; but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals., Comment: 13 pages, 4 figures. v2: updated to match published version
Published: 2021

37. The Refined Composite Downsampling Permutation Entropy Is a Relevant Tool in the Muscle Fatigue Study Using sEMG Signals

Author: Philippe Ravier, Antonio Dávalos, Meryem Jabloun, Olivier Buttelli, Laboratoire pluridisciplinaire de recherche en ingénierie des systèmes, mécanique et énergétique (PRISME), Université d'Orléans (UO)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), IRAuS/Signal, Laboratoire Pluridisciplinaire de Recherche en Ingénierie des Systèmes, Mécanique et Energétique (PRISME), and Université d'Orléans (UO)-Ecole Nationale Supérieure d'Ingénieurs de Bourges (ENSI Bourges)-Université d'Orléans (UO)-Ecole Nationale Supérieure d'Ingénieurs de Bourges (ENSI Bourges)
Subjects: electromyography, Science, Physics, QC1-999, General Physics and Astronomy, Astrophysics, 01 natural sciences, permutation, Article, QB460-466, 03 medical and health sciences, 0302 clinical medicine, multiscale, 0103 physical sciences, fatigue, entropy, downsampling, 010306 general physics, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, 030217 neurology & neurosurgery
Abstract: International audience; Surface electromyography (sEMG) is a valuable technique that helps provide functional and structural information about the electric activity of muscles. As sEMG measures output of complex living systems characterized by multiscale and nonlinear behaviors, Multiscale Permutation Entropy (MPE) is a suitable tool for capturing useful information from the ordinal patterns of sEMG time series. In a previous work, a theoretical comparison in terms of bias and variance of two MPE variants—namely, the refined composite MPE (rcMPE) and the refined composite downsampling (rcDPE), was addressed. In the current paper, we assess the superiority of rcDPE over MPE and rcMPE, when applied to real sEMG signals. Moreover, we demonstrate the capacity of rcDPE in quantifying fatigue levels by using sEMG data recorded during a fatiguing exercise. The processing of four consecutive temporal segments, during biceps brachii exercise maintained at 70% of maximal voluntary contraction until exhaustion, shows that the 10th-scale of rcDPE was capable of better differentiation of the fatigue segments. This scale actually brings the raw sEMG data, initially sampled at 10 kHz, to the specific 0–500 Hz sEMG spectral band of interest, which finally reveals the inner complexity of the data. This study promotes good practices in the use of MPE complexity measures on real data.
Published: 2021
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38. Solar Orbiter/RPW antenna calibration in the radio domain and its application to type III burst observations

Author: M. Steller, Milan Maksimovic, M. Dekkali, E. Lorfèvre, Vratislav Krupar, Antonio Vecchio, Arnaud Zaslavsky, Stuart D. Bale, Yu. V. Khotyaintsev, Vladimir Krasnoselskikh, Štěpán Štverák, Matthieu Kretzschmar, P. L. Astier, Dirk Plettemeier, Xavier Bonnin, Pavel M. Trávníček, J. Soucek, Andris Vaivads, E. Guilhem, T. Chust, Baptiste Cecconi, 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), ALTRAN (FRANCE), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, 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), and Centre National d'Études Spatiales [Toulouse] (CNES)
Subjects: 010504 meteorology & atmospheric sciences, Astronomy, FOS: Physical sciences, Astrophysics, 01 natural sciences, law.invention, Domain (software engineering), Fusion, plasma och rymdfysik, Orbiter, Astronomi, astrofysik och kosmologi, Physics - Space Physics, law, Antenna calibration, 0103 physical sciences, Astronomy, Astrophysics and Cosmology, Aerospace engineering, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), detectors, 0105 earth and related environmental sciences, instrumentation, Physics, Sun: radio radiation, business.industry, instrumentation: detectors, Computer Science::Information Retrieval, Sun, Astronomy and Astrophysics, Fusion, Plasma and Space Physics, Space Physics (physics.space-ph), Astrophysics - Solar and Stellar Astrophysics, solar wind, Space and Planetary Science, radio radiation, Astrophysics - Instrumentation and Methods for Astrophysics, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Context.In order to allow for a comparison with the measurements from other antenna systems, the voltage power spectral density measured by the Radio and Plasma waves receiver (RPW) on board Solar Orbiter needs to be converted into physical quantities that depend on the intrinsic properties of the radiation itself (e.g., the brightness of the source).Aims.The main goal of this study is to perform a calibration of the RPW dipole antenna system that allows for the conversion of the voltage power spectral density measured at the receiver’s input into the incoming flux density.Methods.We used space observations from the Thermal Noise Receiver (TNR) and the High Frequency Receiver (HFR) to perform the calibration of the RPW dipole antenna system. Observations of type III bursts by the Wind spacecraft are used to obtain a reference radio flux density for cross-calibrating the RPW dipole antennas. The analysis of a large sample of HFR observations (over about ten months), carried out jointly with an analysis of TNR-HFR data and prior to the antennas’ deployment, allowed us to estimate the reference system noise of the TNR-HFR receivers.Results.We obtained the effective length,leff, of the RPW dipoles and the reference system noise of TNR-HFR in space, where the antennas and pre-amplifiers are embedded in the solar wind plasma. The obtainedleffvalues are in agreement with the simulation and measurements performed on the ground. By investigating the radio flux intensities of 35 type III bursts simultaneously observed by Wind and Solar Orbiter, we found that while the scaling of the decay time as a function of the frequency is the same for the Waves and RPW instruments, their median values are higher for the former. This provides the first observational evidence that Type III radio waves still undergo density scattering, even when they propagate from the source, in a medium with a plasma frequency that is well below their own emission frequency.
Published: 2021

39. Magnetic reconnection as a mechanism to produce multiple thermal proton populations and beams locally in the solar wind

Author: B. Lavraud, R. Kieokaew, N. Fargette, P. Louarn, A. Fedorov, N. André, G. Fruit, V. Génot, V. Réville, A. P. Rouillard, I. Plotnikov, E. Penou, A. Barthe, L. Prech, C. J. Owen, R. Bruno, F. Allegrini, M. Berthomier, D. Kataria, S. Livi, J. M. Raines, R. D’Amicis, J. P. Eastwood, C. Froment, R. Laker, M. Maksimovic, F. Marcucci, S. Perri, D. Perrone, T. D. Phan, D. Stansby, J. Stawarz, S. Toledo-Redondo, A. Vaivads, D. Verscharen, I. Zouganelis, V. Angelini, V. Evans, T. S. Horbury, H. O’Brien, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), AKKA Technologies, Charles University [Prague] (CU), University College of London [London] (UCL), Laboratoire Population-Environnement-Développement (LPED), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU), The University of Texas at San Antonio (UTSA), Southwest Research Institute [San Antonio] (SwRI), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Mullard Space Science Laboratory (MSSL), University of Michigan [Ann Arbor], University of Michigan System, INAF - Osservatorio Astronomico di Roma (OAR), Istituto Nazionale di Astrofisica (INAF), Imperial College London, 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 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), Università della Calabria [Arcavacata di Rende] (Unical), Italian Space Agency, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, European Space Astronomy Centre (ESAC), European Space Agency (ESA), Royal Institute of Technology [Stockholm] (KTH ), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Agence Spatiale Européenne = European Space Agency (ESA), Science and Technology Facilities Council (STFC), and The Royal Society
Subjects: astro-ph.SR, 010504 meteorology & atmospheric sciences, Proton, FOS: Physical sciences, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, Nuclear physics, Physics - Space Physics, 0201 Astronomical and Space Sciences, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Sun: magnetic fields, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, Computer Science::Information Retrieval, Astronomy and Astrophysics, Magnetic reconnection, Space Physics (physics.space-ph), Solar wind, Astrophysics - Solar and Stellar Astrophysics, solar wind, physics.space-ph, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Mechanism (sociology)
Abstract: Context.Spacecraft data revealed early on the frequent observation of multiple near-thermal proton populations in the solar wind. Decades of research on their origin have focused on processes such as magnetic reconnection in the low corona and wave-particle interactions in the corona and locally in the solar wind.Aims.This study aims to highlight the fact that such multiple thermal proton populations and beams are also produced by magnetic reconnection occurring locally in the solar wind.Methods.We used high-resolution Solar Orbiter proton velocity distribution function measurements, complemented by electron and magnetic field data, to analyze the association of multiple thermal proton populations and beams with magnetic reconnection during a period of slow Alfvénic solar wind on 16 July 2020.Results.At least six reconnecting current sheets with associated multiple thermal proton populations and beams, including a case of magnetic reconnection at a switchback boundary, were found on this day. This represents 2% of the measured distribution functions. We discuss how this proportion may be underestimated, and how it may depend on solar wind type and distance from the Sun.Conclusions.Although suggesting a likely small contribution, but which remains to be quantitatively assessed, Solar Orbiter observations show that magnetic reconnection must be considered as one of the mechanisms that produce multiple thermal proton populations and beams locally in the solar wind.
Published: 2021

40. Characterising the Extended Morphologies of BL Lacertae Objects at 144 MHz with LOFAR

Author: Urszula Pajdosz-Śmierciak, Martin J. Hardcastle, Francesco Massaro, Cathy Horellou, Beatriz Mingo, Raffaella Morganti, Alessandro Capetti, Shane O'Sullivan, M. Pandey-Pommier, Huub Röttgering, G. Gürkan, John L. Quinn, Ranieri D. Baldi, S. Mooney, Astronomy, 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), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), 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), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Active galactic nucleus, Radio galaxy, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, Population, Flux, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Radio source catalogs, radio source catalogs, 01 natural sciences, 158, 1356, 0103 physical sciences, education, 010303 astronomy & astrophysics, media_common, Physics, education.field_of_study, Spectral index, Line-of-sight, 010308 nuclear & particles physics, Computer Science::Information Retrieval, Astronomy and Astrophysics, LOFAR, Astrophysics - Astrophysics of Galaxies, Space and Planetary Science, Sky, BL Lacertae objects, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present a morphological and spectral study of a sample of 99 BL Lac objects using the LOFAR Two-Metre Sky Survey Second Data Release (LDR2). Extended emission has been identified at gigahertz frequencies around BL Lac objects, but with LDR2 it is now possible to systematically study their morphologies at 144 MHz, where more diffuse emission is expected. LDR2 reveals the presence of extended radio structures around 66/99 of the BL Lac nuclei, with angular extents ranging up to 115″, corresponding to spatial extents of 410 kpc. The extended emission is likely to be both unbeamed diffuse emission and beamed emission associated with relativistic bulk motion in jets. The spatial extents and luminosities of the extended emission are consistent with the unification scheme for active galactic nuclei, where BL Lac objects correspond to low-excitation radio galaxies with the jet axis aligned along the line of sight. While extended emission is detected around the majority of BL Lac objects, the median 144–1400 MHz spectral index and core dominance at 144 MHz indicate that the core component contributes ∼42% on average to the total low-frequency flux density. A stronger correlation was found between the 144 MHz core flux density and the γ-ray photon flux (r = 0.69) than between the 144 MHz extended flux density and the γ-ray photon flux (r = 0.42). This suggests that the radio-to-γ-ray connection weakens at low radio frequencies because the population of particles that give rise to the γ-ray flux are distinct from the electrons producing the diffuse synchrotron emission associated with spatially extended features.
Published: 2021

41. Dynamical large deviations for homogeneous systems with long range interactions and the Balescu-Guernsey-Lenard equation

Author: Ouassim Feliachi, Freddy Bouchet, Institut Denis Poisson (IDP), Université d'Orléans (UO)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure de Lyon (ENS de Lyon)-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), The research leading to this work was supported by a sub-agreement from the Johns Hopkins University with funds provided by Grant No. 663054 from Simons Foundation, Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, and Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO)
Subjects: Statistical Mechanics (cond-mat.stat-mech), Widom theorem, 010102 general mathematics, Balescu-Guernsey-Lenard equation, FOS: Physical sciences, Statistical and Nonlinear Physics, Nonlinear Sciences - Chaotic Dynamics, 01 natural sciences, Physics - Plasma Physics, Plasma Physics (physics.plasm-ph), Plasma, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], 0103 physical sciences, [NLIN.NLIN-CD]Nonlinear Sciences [physics]/Chaotic Dynamics [nlin.CD], Macroscopic fluctuation theory, Large deviation theory, 0101 mathematics, Chaotic Dynamics (nlin.CD), [PHYS.COND.CM-SM]Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech], 010306 general physics, Mathematical Physics, Condensed Matter - Statistical Mechanics
Abstract: We establish a large deviation principle for time dependent trajectories (paths) of the empirical density of $N$ particles with long range interactions, for homogeneous systems. This result extends the classical kinetic theory that leads to the Balescu--Guernsey--Lenard kinetic equation, by the explicit computation of the probability of typical and large fluctuations. The large deviation principle for the paths of the empirical density is obtained through explicit computations of a large deviation Hamiltonian. This Hamiltonian encodes all the cumulants for the fluctuations of the empirical density, after time averaging of the fast fluctuations. It satisfies a time reversal symmetry, related to the detailed balance for the stochastic process of the empirical density. This explains in a very simple way the increase of the macrostate entropy for the most probable states, while the stochastic process is time reversible, and describes the complete stochastic process at the level of large deviations., Comment: arXiv admin note: text overlap with arXiv:2101.04455
Published: 2021

42. Gas-phase rate coefficient of OH + cyclohexene oxide measured from 251 to 373 K

Author: Max R. McGillen, Hajar El Othmani, Yangang Ren, Abdelwahid Mellouki, Véronique Daële, Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut des Sciences de l'Ingénierie et des Systèmes (INSIS - 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), Université Mohammed V de Rabat [Agdal] (UM5), ANR-10-LABX-0100,VOLTAIRE,Geofluids and Volatil elements – Earth, Atmosphere, Interfaces – Resources and Environment(2010), European Project: 730997,EUROCHAMP2020(2020), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut des Sciences de l'Ingénierie et des Systèmes (INSIS), 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), and Mohammed V University in Rabat
Subjects: 010304 chemical physics, Bicyclic molecule, Chemistry, Photodissociation, Kinetics, Oxide, General Physics and Astronomy, Epoxide, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Hydroxyl Atmospheric chemistry, chemistry.chemical_compound, Reaction rate constant, Kinetics Rate constant, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Physical chemistry, Reactivity (chemistry), Physical and Theoretical Chemistry, Oxirane, Cyclohexene oxide
Abstract: International audience; Absolute measurements of the rate coefficient of the title reaction are reported from 251 to 373 K using the laser-induced fluorescence–pulsed-laser photolysis technique, together with room-temperature relative rate determinations using a simulation chamber. These are the first reported values of this rate coefficient, which demonstrates a predominantly negative temperature dependence that is more pronounced than with other epoxides, suggesting that pre-reactive complexes contribute to the overall reactivity, and that these complexes are comparatively stable for OH + cyclohexene oxide, which may result from its bicyclic structure. This work provides new insights into the lesser-studied reactivity of the epoxide functionality.
Published: 2021

43. 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

44. Rapid solidification synthesis of novel (La,Y)2(Zr,Ti)2O7 pyrochlore-based glass-ceramics for the immobilization of high-level wastes

Author: Hong Sun, Ying Zhang, Emmanuel Véron, Yongchang Guo, Jianqiang Li, Shaowei Feng, Cécile Genevois, Mathieu Allix, Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO), and Université d'Orléans (UO)
Subjects: Materials science, Pyrochlore, Sintering, 02 engineering and technology, engineering.material, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 01 natural sciences, law.invention, law, Phase (matter), 0103 physical sciences, Materials Chemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Thermal stability, Ceramic, Crystallization, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Borosilicate glass, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Amorphous solid, Chemical engineering, visual_art, Ceramics and Composites, engineering, visual_art.visual_art_medium, 0210 nano-technology
Abstract: Pyrochlore-based glass-ceramics are attracting attention as a promising host material for immobilizing minor actinide in high-level wastes. However, the loading capacity of pyrochlore-based materials for actinide elements is to be improved, and only conventional synthetic approaches of powder sintering and glassy bulk crystallization were reported. Here, new (La,Y)2(Zr,Ti)2O7 pyrochlore-based glass-ceramics were subtly designed and successfully prepared through a rapid melting and solidification process. The solidification behavior of samples with different cooling rates was investigated, the dense and crack-free (La,Y)2(Zr,Ti)2O7 pyrochlore-based glass-ceramics were prepared at the cooling rate of 500 °C/s (within 1.5 s). The present amorphous La2O3-TiO2-Al2O3 phase demonstrates the outstanding thermal stability compared with the currently used borosilicate glass for high-level waste immobilization due to the lack of conventional glass-forming components. The results show the great feasibility of this novel synthesis route for glass-ceramics by direct solidification and its good potential for immobilizing high-level wastes.
Published: 2021

45. Glass forming regions, structure and properties of lanthanum barium germanate and gallate glasses

Author: Marc Dussauze, Véronique Jubera, Florian Calzavara, Thierry Cardinal, Marcelo Nalin, Evelyne Fargin, Mathieu Allix, Université de Bordeaux, 1 Avenue de la Recherche Scientifique, 351 cours de la Libération, Universidade Estadual Paulista (UNESP), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institute of Chemistry [University of São Paulo] | Instituto de Química [Universidade de São Paulo], University of São Paulo (USP), This research was supported by Agence Nationale de la Recherche (ANR) (ANR-18-CE08-0004-02) and the New Aquitaine Region. This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 823941 (FUNGLASS), as well as grants of the Agence Nationale de la Recherche (ANR) with the program 'Investissement d'avenir' number ANR-10-IDEX-03-02. M. Nalin acknowledge the São Paulo Research Foundation, FAPESP (grant numbers 2013/07793-6 and 2019/01223-0). The authors acknowledge the platform SIV for vibrational spectroscopy characterizations., ANR-10-IDEX-0003,IDEX BORDEAUX,Initiative d'excellence de l'Université de Bordeaux(2010), ANR-18-CE08-0004,FLAG-IR,Fabrication 3D de composants optiques intégrés à bas cout par laser femtoseconde pour des applications IR(2018), European Project: 664440,H2020,H2020-WIDESPREAD-2014-1,FunGLASS(2015), Institute of Chemistry, University of São Paulo, Université d'Orléans (UO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Universidade de São Paulo = University of São Paulo (USP)
Subjects: Materials science, Vibrational Infrared and Raman spectroscopies, Germano-gallate glasses, chemistry.chemical_element, Germanium, 02 engineering and technology, 01 natural sciences, Aerodynamic levitation, 010309 optics, Glass structure, symbols.namesake, 0103 physical sciences, Materials Chemistry, Lanthanum, Germanate, Gallium, Aerodynamic levitation coupled to laser heating, Barium, Gallate, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, chemistry, Heavy-metal oxide glasses, Ceramics and Composites, symbols, Physical chemistry, 0210 nano-technology, Raman spectroscopy
Abstract: Made available in DSpace on 2022-04-28T19:41:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Horizon 2020 Framework Programme Agence Nationale de la Recherche Glass forming regions in the system GaO3/2 – GeO2 – LaO3/2 – BaO have been explored using aerodynamic levitation coupled to laser heating synthesis technique. Structure property relationships have been established between the thermal and optical properties of the resulting glass thanks to Raman and Infrared vibrational spectroscopies. The germano-gallate glass networks are mainly made of three-dimensional interconnected corner shared GeO4 and GaO4 tetrahedra forming Ge – O – Ge and Ga – O− – Ge bridges in which gallium tetrahedral GaO4 units are charged-compensated by barium and lanthanum cations. In GeO2-rich compositions, the excess of positive charges produces mainly non-bridging oxygens on germanate moieties, leading to a depolymerization of the glass network. In the case of gallium rich compositions, the infrared cut-off is red-shifted as compared to the germanate glasses, in accordance with the disappearance of germanium associated entities such as germanium and gallium bridges or germanium sites with non-bridging oxygen both vibrating at higher wavenumber. Institut de Chimie de la Matière Condensée de Bordeaux Université de Bordeaux, 87 Avenue du Dr Schweitzer Conditions Extrêmes et Matériaux Haute Température et Irradiation UPR3079 Université d'Orléans 1 Avenue de la Recherche Scientifique Institut des Sciences Moléculaires UMR 5255 Université́ de Bordeaux 351 cours de la Libération Institute of Chemistry São Paulo State University-UNESP Rua Prof. Francisco Degni, 55, CEP 14800-060 Institute of Chemistry São Paulo State University-UNESP Rua Prof. Francisco Degni, 55, CEP 14800-060 FAPESP: 2013/07793-6 FAPESP: 2019/01223-0 Horizon 2020 Framework Programme: 823941 Agence Nationale de la Recherche: ANR-10-IDEX-03-02 Agence Nationale de la Recherche: ANR-18-CE08-0004-02
Published: 2021

46. Parametrization, structure and Bruhat order of certain spherical quotients

Author: Lucas Fresse, Pierre-Emmanuel Chaput, Thomas Gobet, Institut Élie Cartan de Lorraine (IECL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Denis Poisson (IDP), Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO), The first two authors are supported in part by the ANR project GeoLie ANR-15-CE40-0012. The last author was partially supported by the same project and by the ARC project DP170101579., ANR-15-CE40-0012,GéoLie,Méthodes géométriques en théorie de Lie(2015), and Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO)
Subjects: Pure mathematics, MathematicsofComputing_GENERAL, 01 natural sciences, Mathematics - Algebraic Geometry, Mathematics (miscellaneous), 0103 physical sciences, Lie algebra, [MATH.MATH-CO]Mathematics [math]/Combinatorics [math.CO], FOS: Mathematics, Mathematics - Combinatorics, 0101 mathematics, Representation Theory (math.RT), GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Algebraic Geometry (math.AG), Mathematics, [MATH.MATH-RT]Mathematics [math]/Representation Theory [math.RT], Flag (linear algebra), 010102 general mathematics, Coxeter group, 16. Peace & justice, Bruhat order, Nilpotent, Algebraic group, Affine bundle, 010307 mathematical physics, Combinatorics (math.CO), Astrophysics::Earth and Planetary Astrophysics, [MATH.MATH-AG]Mathematics [math]/Algebraic Geometry [math.AG], Variety (universal algebra), Mathematics - Representation Theory
Abstract: Let $G$ be a reductive algebraic group and let $Z$ be the stabilizer of a nilpotent element $e$ of the Lie algebra of $G$. We consider the action of $Z$ on the flag variety of $G$, and we focus on the case where this action has a finite number of orbits (i.e., $Z$ is a spherical subgroup). This holds for instance if $e$ has height $2$. In this case we give a parametrization of the $Z$-orbits and we show that each $Z$-orbit has a structure of algebraic affine bundle. In particular, in type $A$, we deduce that each orbit has a natural cell decomposition. In the aim to study the (strong) Bruhat order of the orbits, we define an abstract partial order on certain quotients associated to a Coxeter system. In type $A$, we show that the Bruhat order of the $Z$-orbits can be described in this way., 42 pages, 2 figures
Published: 2021

47. Nonlinear mirror image method for nonlinear Schrödinger equation: Absorption/emission of one soliton by a boundary

Author: Vincent Caudrelier, Nicolas Crampé, Carlos Mbala Dibaya, School of Mathematics - University of Leeds, University of Leeds, Institut Denis Poisson (IDP), Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO), School of Mathematics [Leeds], and Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO)
Subjects: High Energy Physics - Theory, Integrable system, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Boundary (topology), integrability, 01 natural sciences, symbols.namesake, Schroedinger equation: nonlinear, [NLIN.NLIN-PS]Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS], Method of images, 0103 physical sciences, Baecklund transformation, [NLIN.NLIN-SI]Nonlinear Sciences [physics]/Exactly Solvable and Integrable Systems [nlin.SI], Boundary value problem, 0101 mathematics, 010306 general physics, Nonlinear Schrödinger equation, boundary condition: time dependence, Mathematical Physics, transformation: mirror, Physics, Nonlinear Sciences - Exactly Solvable and Integrable Systems, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Applied Mathematics, 010102 general mathematics, Mathematical analysis, mathematical methods, Nonlinear Sciences - Pattern Formation and Solitons, Robin boundary condition, Nonlinear system, symbols, Soliton, absorption, soliton
Abstract: We perform the analysis of the focusing nonlinear Schr\"odinger equation on the half-line with time-dependent boundary conditions along the lines of the nonlinear method of images with the help of B\"acklund transformations. The difficulty arising from having such time-dependent boundary conditions at $x=0$ is overcome by changing the viewpoint of the method and fixing the B\"acklund transformation at infinity as well as relating its value at $x=0$ to a time-dependent reflection matrix. The interplay between the various aspects of integrable boundary conditions is reviewed in detail to brush a picture of the area. We find two possible classes of solutions. One is very similar to the case of Robin boundary conditions whereby solitons are reflected at the boundary, as a result of an effective interaction with their images on the other half-line. The new regime of solutions supports the existence of one soliton that is not reflected at the boundary but can be either absorbed or emitted by it. We demonstrate that this is a unique feature of time-dependent integrable boundary conditions., Comment: 38 pages. 5 figures. Authors' version of the published article. Accessiblefrom https://onlinelibrary.wiley.com/doi/10.1111/sapm.12456
Published: 2021

48. Time-Dependent Conformal Transformations and the Propagator for Quadratic Systems

Author: Peter A. Horvathy, Pengming Zhang, Qiliang Zhao, School of Physics and Astronomy [Zhuhai], Sun Yat-Sen University [Guangzhou] (SYSU), Institut Denis Poisson (IDP), Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO), Partially supported by the National Natural Science Foundation of China (Grant No. 11975320)., and Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO)
Subjects: High Energy Physics - Theory, Physics and Astronomy (miscellaneous), General Mathematics, FOS: Physical sciences, Conformal map, frequency: time dependence, classical general relativity, 01 natural sciences, PACS : 03.65.-w, 03.65.Sq, 04.20.-q, Quadratic equation, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], 0103 physical sciences, oscillator, Computer Science (miscellaneous), QA1-939, 010306 general physics, Quantum, Mathematical Physics, transformation: conformal, Mathematical physics, Physics, Quantum Physics, Mathieu, 010308 nuclear & particles physics, Phase correction, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], quantum mechanics, Propagator, Mathematical Physics (math-ph), Quadratic system, Transformation (function), High Energy Physics - Theory (hep-th), Chemistry (miscellaneous), semiclassical theories and applications, Free form, propagator, Quantum Physics (quant-ph), Mathematics
Abstract: The method proposed by Inomata and his collaborators allows us to transform a damped Caldiroli-Kanai oscillator with time-dependent frequency to one with constant frequency and no friction by redefining the time variable, obtained by solving a Ermakov-Milne-Pinney equation. Their mapping ``Eisenhart-Duval'' lifts as a conformal transformation between two appropriate Bargmann spaces. The quantum propagator is calculated also by bringing the quadratic system to free form by another time-dependent Bargmann-conformal transformation which generalizes the one introduced before by Niederer and is related to the mapping proposed by Arnold. Our approach allows us to extend the Maslov phase correction to arbitrary time-dependent frequency. The method is illustrated by the Mathieu profile., Comment: This paper celebrates the 90th birthday of Akira Inomata. 28 pages, 5 figures. Matches published version
Published: 2021

49. The Solar Orbiter Radio and Plasma Waves (RPW) instrument (Corrigendum)

Author: Andris Vaivads, V. Krupař, M. Chariet, Lars Bylander, L. R. Malac-Allain, J. Parisot, Mats André, W. Recart, W. Puccio, C. Agrapart, D. Bérard, V. Leray, Robert F. Wimmer-Schweingruber, K. Boughedada, Baptiste Cecconi, E. Lorfèvre, M. Steller, B. Katra, F. Chapron, Helmut O. Rucker, Stuart D. Bale, Matthieu Kretzschmar, J.-C. Pellion, Ivana Kolmasova, J. Sanisidro, N. Quéruel, Filippo Pantellini, V. Bouzid, Laurent Lamy, Milan Maksimovic, L. Guéguen, C. Fiachetti, S. Chaintreuil, Mykhaylo Panchenko, Karine Issautier, M. Dekkali, O. Krupařová, Keith Goetz, Tomas Karlsson, I. Fratter, H. Ottacher, Philippe Louarn, P. Fergeau, O. Le Contel, Christopher J. Owen, Jan Soucek, A. Retino, Mihailo M. Martinović, Y. de Conchy, Olga Alexandrova, E. Bellouard, G. T. Delory, David Pisa, S. Thijs, E. Guilhem, Anders Eriksson, L. Åhlén, Antonio Vecchio, Timothy S. Horbury, Ondrej Santolik, Eduard P. Kontar, T. Vincent, V. Cripps, Daniel Dias, I. Zouganelis, A. Jeandet, T. Dudok de Wit, Sonny Lion, L. Uhlíř, Quynh Nhu Nguyen, M. Timofeeva, Dirk Plettemeier, J. Baše, Christopher Cully, Petr Hellinger, Lorenzo Matteini, Fouad Sahraoui, C. Collin, Paul Turin, Javier Rodriguez-Pacheco, Säm Krucker, P. Plasson, J.-Y. Brochot, Vladimir Krasnoselskikh, P. Leroy, Petr Travnicek, R. Lán, Yu. V. Khotyaintsev, S.-E. Jansson, Štěpán Štverák, G. Barbary, Pierre Astier, G. Jannet, R. Piberne, E. P. G. Johansson, F. Gonzalez, P. Danto, Arnaud Zaslavsky, J. Břínek, Thomas Chust, Xavier Bonnin, C. Laffaye, G. Cassam-Chenai, S. Julien, B. Pontet, Matthieu Berthomier, 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), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), 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), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Commission for Astronomy of the Austrian Academy of Sciences, Austrian Academy of Sciences (OeAW), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), Space Research Institute of Austrian Academy of Sciences (IWF), Royal Institute of Technology [Stockholm] (KTH ), 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 d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Nexeya Conseil & Formation, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud university [Nijmegen], Centre National d'Études Spatiales [Toulouse] (CNES), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ALTRAN (FRANCE), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), Univerzita Karlova v Praze, Universities Space Research Association (USRA), NASA Goddard Space Flight Center (GSFC), Department of Physics and Astronomy [Calgary], University of Calgary, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Department of Physics [Imperial College London], Imperial College London, University of Glasgow, Fachhochschule Nordwestschweiz [Windisch] (FHNW), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, University of Belgrade [Belgrade], Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Universidad de Alcalá - University of Alcalá (UAH), Institute of Experimental and Applied Physics [Kiel] (IEAP), Christian-Albrechts-Universität zu Kiel (CAU), European Space Astronomy Centre (ESAC), European Space Agency (ESA), 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), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Radboud University [Nijmegen], Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Université de Rennes (UR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Agence Spatiale Européenne = European Space Agency (ESA)
Subjects: Physics, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, Astrophysics, Plasma, 01 natural sciences, law.invention, instrumentation: miscellaneous, Solar wind, Orbiter, solar wind, Space and Planetary Science, law, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, addenda, ComputingMilieux_MISCELLANEOUS, errata
Abstract: Contains fulltext : 239392.pdf (Publisher’s version ) (Open Access)
Published: 2021

50. Stationary generalizations for the Bronnikov-Ellis wormhole and for the vacuum ring wormhole

Author: Mikhail Volkov, Institut Denis Poisson (IDP), Centre National de la Recherche Scientifique (CNRS)-Université de Tours-Université d'Orléans (UO), and Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Université d'Orléans (UO)
Subjects: High Energy Physics - Theory, geometry, perturbation, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), angular momentum, wormhole: mass, 01 natural sciences, solution: static, General Relativity and Quantum Cosmology, vacuum state, Ernst equation, 0103 physical sciences, 010306 general physics, background, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, screening, singularity, field theory: scalar, High Energy Physics - Theory (hep-th), wormhole: rotation, space-time, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], tension: negative, simplex
Abstract: We analyze possibilities to obtain a globally regular stationary generalization for the ultrastatic wormhole with a repulsive scalar field found by Bronnikov and by Ellis in 1973. The extreme simplicity of this static solution suggests that its stationary version could be obtainable analytically and should be globally regular, but no such generalization has been found. We analyze the problem and find that the difficulty originates in the vacuum theory, since the scalar field can be eliminated within the Eris-Gurses procedure. The problem then reduces to constructing the spinning generalization for the vacuum wormhole sourced by a thin ring of negative tension. Solving the vacuum Ernst equations determines the $g_{00}$, $g_{0\varphi}$ metric components and hence the AMD mass ${\rm M}$ and angular momentum ${\rm J}$, all of these being specified by the ring source. The scalar field can be included into consideration afterwords, but this only affects $g_{rr}$ and $g_{\vartheta\vartheta}$ without changing the rest. Within this approach, we analyze a number of exact stationary generalizations for the wormhole, but none of them are satisfactory. However, the perturbative expansion around the static vacuum background contains only bounded functions and presumably converges to an exact solution. Including the scalar field screens the singularity at the ring source and renders the geometry regular. This solution describes a globally regular spinning wormhole with two asymptotically flat regions. Even though the source itself is screened and not visible, the memory of it remains in $g_{00}$ and $g_{0\varphi}$ and accounts for the ${\rm M}\propto {\rm J}^2$ relation typical for a rotating extended source. Describing stationary spacetimes with an extended source is a complicated problem, which presumably explains the difficulty in finding the solution., Comment: 37 pages, references added, minor style improvements
Published: 2021

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