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Concept

Télescope Lovell

Publications associées (15)

The effect of pressure-anisotropy-driven kinetic instabilities on magnetic field amplification in galaxy clusters

Salim Bennouna, Yoan Rappaz

Context. The intracluster medium (ICM) is the low-density diffuse gas that fills the space between galaxies within galaxy clusters. It is primarily composed of magnetized plasma, which reaches virial temperatures of up to 10(8) K, probably due to mergers o ...

Edp Sciences S A2024

The GRANDMA network in preparation for the fourth gravitational-wave observing run

Jieping Zhu, Jean-Paul Richard Kneib

GRANDMA is a world-wide collaboration with the primary scientific goal of studying gravitational-wave sources, discovering their electromagnetic counterparts and characterizing their emission. GRANDMA involves astronomers, astrophysicists, gravitational-wa ...

SPIE-INT SOC OPTICAL ENGINEERING2022

Potential of Radio Telescopes as High-Frequency Gravitational Wave Detectors

Valerie Fiona Domcke

In the presence of magnetic fields, gravitational waves are converted into photons and vice versa. We demonstrate that this conversion leads to a distortion of the cosmic microwave background (CMB), which can serve as a detector for MHz to GHz gravitationa ...

2021

A radio ridge connecting two galaxy clusters in a filament of the cosmic web

Claudio Gheller

Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intracluster gas. We observed a ridge of radio emission connect ...

American Association for the Advancement of Science2019

Towards More Accurate Radio Telescope Images

Paul Hurley, Matthieu Martin Jean-André Simeoni

Radio interferometry usually compensates for high levels of noise in sensor/antenna electronics by throwing data and energy at the problem: observe longer, then store and process it all. We propose instead a method to remove the noise explicitly before ima ...

IEEE2018

Low-dimensional data embedding for scalable astronomical imaging in the SKA telescope era

Vijay Kartik

Astronomy is one of the oldest sciences known to humanity. We have been studying celestial objects for millennia, and continue to peer deeper into space in our thirst for knowledge about our origins and the universe that surrounds us. Radio astronomy -- ob ...

EPFL2018

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses XV. Assessing the achievability and precision of time-delay measurements

Frédéric Courbin, Georges Meylan, Vivien François Bonvin, Malte Tewes, Thibault Adrien Kuntzer

COSMOGRAIL is a long-term photometric monitoring of gravitationally lensed quasars aimed at implementing Refsdal's time-delay method to measure cosmological parameters, in particular H-0. Given the long and well sampled light curves of strongly lensed quas ...

Edp Sciences S A2016

High-redshift supernova rates measured with the gravitational telescope A 1689

Jean-Paul Richard Kneib

Aims. We present a ground-based, near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z = 0.18, which is one of the most powerful gravitational telescopes that nature provides. Methods. Our survey was based on multi-epoch J-b ...

Edp Sciences S A2016

Dimension embedding for big data in radio interferometry

Yves Wiaux, Rafael Eduardo Carrillo Rangel, Vijay Kartik

As radio telescope data is now increasingly high-dimensional, data reduction has become essential to reduce computational load while preserving accurate signal reconstruction. Gridding the continuous Fourier visibilities represents the standard approach to ...

2015

Large scale structures around medium mass galaxy clusters at intermediate redshift

François Henri Ambroise Rérat

Theory predicts that galaxies are not randomly distributed in the Universe. They form a complex network of filamentary structures, the Cosmic Web, divided in clusters, groups, filaments and walls. This picture has been confirmed by the large galaxy redshif ...

EPFL2015

The Red Radio Ring: a gravitationally lensed hyperluminous infrared radio galaxy at z=2.553 discovered through the citizen science project SPACE WARPS

Jean-Paul Richard Kneib, Ajay Kumar Verma

We report the discovery of a gravitationally lensed hyperluminous infrared galaxy (intrinsic L-IR approximate to 10(13) L-circle dot) with strong radio emission (intrinsic L-1.4 GHz approximate to 10(25) WHz(-1)) at z = 2.553. The source was identified in ...

Oxford University Press2015

The application of Compressed Sensing Techniques in Radio Astronomy

Yves Wiaux

Radio interferometry probes astrophysical signals through incomplete and noisy Fourier measurements. The optimal reconstruction of these signals is an important topic not only for current astronomical imaging but also that of the next generation of radio t ...

IEEE2011

On the Characteristics of Highly Confined Light Fields : A High-Resolution Interference Microscopy Study

Myun Sik Kim

The Investigation of highly confined light fields created by different mechanisms, such as refraction, diffraction, and scattering, are the main subject of this thesis. We distinguish a specific scattering phenomenon of dielectric microspheres from general ...

EPFL2011

Compressed sensing imaging techniques for radio interferometry

Pierre Vandergheynst, Yves Wiaux, Gilles Puy, Laurent Jacques

Radio interferometry probes astrophysical signals through incomplete and noisy Fourier measurements. The theory of compressed sensing demonstrates that such measurements may actually suffice for accurate reconstruction of sparse or compressible signals. We ...

Wiley-Blackwell2009

Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars

Andrea Kraus

Magnetars(1) are young neutron stars with very strong magnetic fields of the order of 10(14)-10(15) G. They are detected in our Galaxy either as soft gamma-ray repeaters or anomalous X-ray pulsars. Soft gamma-ray repeaters are a rare type of gamma-ray tran ...

2008