Concept

Télescope géant

Publications associées (21)

Probing the faint-end luminosity function of Lyman-alpha emitters at 3 < z < 7 behind 17 MUSE lensing clusters

Context. This paper presents a study of the galaxy Lyman-alpha luminosity function (LF) using a large sample of 17 lensing clusters observed by the Multi Unit Spectroscopic Explorer (MUSE) at the ESO Very Large Telescope (VLT). The magnification resulting ...

Edp Sciences S A2023

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

The Pristine survey - XVII. The C-19 stream is dynamically hot and more extended than previously thought

Pascale Jablonka, Carmela Lardo

The C-19 stream is the most metal-poor stellar system ever discovered, with a mean metallicity [Fe/H] = -3.38 +/- 0.06. Its low metallicity dispersion (sigma([Fe/H]) < 0.18 at the 95 per cent confidence level) and variations in sodium abundances strongly s ...

OXFORD UNIV PRESS2022

The Tucana dwarf spheroidal galaxy: not such a massive failure after all

Pascale Jablonka

Context. Isolated local group (LG) dwarf galaxies have evolved most or all of their life unaffected by interactions with the large LG spirals and therefore offer the opportunity to learn about the intrinsic characteristics of this class of objects. Aims. O ...

2020

Precision Positioning of Microrobots for Multi-Object Spectrographs

Luzius Gregor Kronig

How does one study the evolution of the Milky Way, or the expansion of the Universe, or explore the mysteries of Dark energy? To investigate these complex topics, astronomers require data, and a great deal of it, in the form of the spectra of stars, galaxi ...

EPFL2020

Kinematic and metallicity properties of the Aquarius dwarf galaxy from FORS2 MXU spectroscopy

Pascale Jablonka

Context. Dwarf galaxies found in isolation in the Local Group (LG) are unlikely to have interacted with the large LG spirals, and therefore environmental effects such as tidal and ram-pressure stripping should not be the main drivers of their evolution. Ai ...

EDP SCIENCES S A2020

Hubble Frontier Fields: predictions for the return of SN Refsdal with the MUSE and GMOS spectrographs

Jean-Paul Richard Kneib, Hakim Atek, Benjamin Yvan Alexandre Clement, Markus Rexroth

We present a high-precision mass model of the galaxy cluster MACS J1149.6+ 2223, based on a strong gravitational lensing analysis of Hubble Space Telescope Frontier Fields (HFF) imaging data and spectroscopic follow-up with Gemini/Gemini Multi-Object Spect ...

Oxford Univ Press2016

Teraelectronvolt pulsed emission from the Crab Pulsar detected by MAGIC

Thomas Günther Bretz

Aims. We investigate the extension of the very high-energy spectral tail of the Crab Pulsar at energies above 400 GeV. Methods. We analyzed similar to 320 h of good-quality Crab data obtained with the MAGIC telescope from February 2007 to April 2014. Resul ...

Edp Sciences S A2016

The 0.1 < z < 1.65 evolution of the bright end of the [O II] luminosity function

Jean-Paul Richard Kneib, Jun Ma, David Schlegel, Timothée Guy Olivier Delubac

We present the [O II] (lambda lambda 3729; 3726) luminosity function measured in the redshift range 0.1 < z < 1.65 with unprecedented depth and accuracy. Our measurements are based on medium resolution flux-calibrated spectra of emission line galaxies with ...

EDP Sciences2015

ARE ULTRA-FAINT GALAXIES AT z=6-8 RESPONSIBLE FOR COSMIC REIONIZATION? COMBINED CONSTRAINTS FROM THE HUBBLE FRONTIER FIELDS CLUSTERS AND PARALLELS

Jean-Paul Richard Kneib, Hakim Atek, Benjamin Yvan Alexandre Clement

We use deep Hubble Space Telescope imaging of the Frontier Fields to accurately measure the galaxy rest-frame ultraviolet luminosity function (UV LF) in the redshift range z similar to 6-8. We combine observations in three lensing clusters, A2744, MACS 041 ...

Iop Publishing Ltd2015

Spectroscopic needs for imaging dark energy experiments

Jean-Paul Richard Kneib

Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z's): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, ...

Elsevier2015

FIRST NuSTAR OBSERVATIONS OF MRK 501 WITHIN A RADIO TO TeV MULTI-INSTRUMENT CAMPAIGN

Xin Chen, Thomas Günther Bretz

We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL La ...

Iop Publishing Ltd2015

Design and operation of FACT - the first G-APD Cherenkov telescope

Mathieu Ribordy, Camille Haller, Thomas Günther Bretz

The First G-APD Cherenkov Telescope (FACT) is designed to detect cosmic gamma-rays with energies from several hundred GeV up to about 10 TeV using the Imaging Atmospheric Cherenkov Technique. In contrast to former or existing telescopes, the camera of the ...

Iop Publishing Ltd2013

The outer halo of the nearest giant elliptical: a VLT/VIMOS survey of the resolved stellar populations in Centaurus A to 85 kpc

Pascale Jablonka

We present the first survey of resolved stellar populations in the remote outer halo of our nearest giant elliptical (gE), Centaurus A (D = 3.8 Mpc). Using the VIsible Multi Object Spectrograph (VIMOS)/Very Large Telescope (VLT) optical camera, we obtained ...

Oxford Univ Press2013

The ESPRI project: astrometric exoplanet search with PRIMA I. Instrument description and performance of first light observations

Ludger Weber

Context. The ESPRI project relies on the astrometric capabilities offered by the PRIMA facility of the Very Large Telescope Interferometer for discovering and studying planetary systems. Our survey consists of obtaining high-precision astrometry for a larg ...

Edp Sciences S A2013

Spectroscopy of extended Ly alpha envelopes around z=4.5 quasars

Frédéric Courbin, Pierre North, Alexander Patrick Eigenbrod

What are the frequency, shape, kinematics, and luminosity of Ly alpha envelopes surrounding radio-quiet quasars at high redshift, and is the luminosity of these envelopes related to that of the quasar or not? As a first step towards answering these questio ...

2012

Nucleosynthesis And The Inhomogeneous Chemical Evolution Of The Carina Dwarf Galaxy

Pascale Jablonka

The detailed abundances of 23 chemical elements in nine bright red giant branch stars in the Carina dwarf spheroidal galaxy are presented based on high-resolution spectra gathered at the Very Large Telescope (VLT) and Magellan telescopes. A spherical model ...

2012

Time course of flow-induced adaptation of carotid artery biomechanical properties, structure and zero-stress state in the arteriovenous shunt

Nikolaos Stergiopoulos

Numerous studies have provided evidence of diameter adaptation secondary to flow-overload. but with ambiguous findings vis a vis other morphological parameters and information on the biomechanical aspects of arterial adaptation is rather incomplete. We exa ...

2012

Astrophysical applications of gravitationally lensed quasars : from dark matter halos to the structure of quasar accretion disks

Alexander Patrick Eigenbrod

Gravitational lensing describes how light is deflected as it passes in the vicinity of a mass distribution. The amplitude of the deflection is proportional to the mass of the deflector, called "gravitational lens", and is generally weak, even for large mas ...

EPFL2008

Deep optical spectroscopy of extended Ly alpha emission around three radio-quiet z=4.5 quasars

Frédéric Courbin, Pierre North, Alexander Patrick Eigenbrod

We report the first results of a spectroscopic search for Ly alpha envelopes around three z similar to 4.5 radio-quiet quasars. Our observational strategy adopts the FORS2 spectrograph mounted to the UT1 of the Very Large Telescope (VLT) in the multi-slit ...

2008