Michel Tagger

Observations of carbon radio recombination lines with the NenuFAR telescope

Lucie Cros, Antoine Gusdorf, Philippe L. Salomé, S. V. Stepkin et autres

Context. Carbon radio recombination lines (CRRLs) at decametre wavelengths trace the diffuse phase of the interstellar medium (ISM) of the Galaxy. Observations of these lines allow for physical parameters of this phase to be measured. Aims. We observed CRRLs with the recently …

fr, ua, it, es, ca, au, nl (code pays fourni par la source)

A circularly polarized low-frequency radio burst from the exoplanetary system HD 189733

X. Zhang, Philippe Zarka, J. N. Girard, Cyril Tasse et autres

Aims. We aim to detect low-frequency radio emission from exoplanetary systems to gain insights into planetary magnetic fields, star–planet interactions, stellar activity, and exo-space weather. The HD 189733 system, hosting a well-studied hot Jupiter, is a prime target for such searches. Methods. …

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

E. Bonnassieux, Evangelia Tremou, J. N. Girard, Alan Loh et autres

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 …

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Observations of Shock Propagation through Turbulent Plasma in the Solar Corona

Eoin Carley, Baptiste Cecconi, Hamish Reid, C. Briand et autres

Abstract Eruptive activity in the solar corona can often lead to the propagation of shock waves. In the radio domain the primary signature of such shocks are type II radio bursts, observed in dynamic spectra as bands of emission slowly drifting toward …

ie, fr, gb, ua, nl (code pays fourni par la source)

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

Leah K. Morabito, Neal J Jackson, S. Mooney, Frits Sweijen et autres

[abridged] The International LOFAR Telescope is an interferometer with stations spread across Europe. With baselines of up to ~2,000 km, LOFAR has the unique capability of achieving sub-arcsecond resolution at frequencies below 200 MHz, although this is technically and logistically challenging. Here …

Sub-arcsecond imaging with the International LOFAR Telescope: II. Completion of the LOFAR Long-Baseline Calibrator Survey

Neal J Jackson, Shruti Badole, John S. Morgan, Rajan Chhetri et autres

The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper we present the complete survey, building on the preliminary analysis published in …

Sub-arcsecond imaging with the International LOFAR Telescope

Neal J Jackson, Shruti Badole, John S. Morgan, Rita Chhetri et autres

The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper, we present the complete survey, building on the preliminary analysis published in …

gb, au, lv, nl, ie, es, de, in, it, be, fr, us, pl, Afrique du Sud (code pays fourni par la source)

Sub-arcsecond imaging with the International LOFAR Telescope

Leah K. Morabito, Neal J Jackson, S. Mooney, Frits Sweijen et autres

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 …

gb, ie, nl, se, de, it, au, es, fr, Afrique du Sud, in, be, us, pl (code pays fourni par la source)

Cassiopeia A, Cygnus A, Taurus A, and Virgo A at ultra-low radio frequencies

F. de Gasperin, Jacco Vink, J. P. McKean, A. Asgekar et autres

Context. The four persistent radio sources in the northern sky with the highest flux density at metre wavelengths are Cassiopeia A, Cygnus A, Taurus A, and Virgo A; collectively they are called the A-team. Their flux densities at ultra-low frequencies (< 100 …

de, nl, in, it, au, gb, be, pl, fr, Afrique du Sud, se, us (code pays fourni par la source)

VizieR Online Data Catalog: CasA, CygA, TauA, VirA 30MHz & 77MHz models (de Gasperin+, 2020)

F. de Gasperin, J. Vink, J. P. McKean, A. Asgekar et autres

LithoSpace : un système de préparation de lames pétrographiques automatisé pour l’exploration planétaire et la géologie de terrain

Frédéric Foucher, Nicolas Bost, S. Janiec, Francès Westall et autres

International audience

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Needle-like structures discovered on positively charged lightning branches

Brian M. Hare, Olaf Scholten, J. R. Dwyer, T. N. G. Trinh et autres

nl, be, us, de, au, gb, fr, pl, Afrique du Sud (code pays fourni par la source)