Publications associées à Performance of the MALTA telescope

The Pixel Luminosity Telescope: a detector for luminosity measurement at CMS using silicon pixel sensors

Alexis Kalogeropoulos, Valérie Scheurer, Joanna Malgorzata Wanczyk, André Donadon Servelle

The Pixel Luminosity Telescope is a silicon pixel detector dedicated to luminosity measurement at the CMS experiment at the LHC. It is located approximately 1.75 m from the interaction point and arranged into 16 "telescopes", with eight telescopes installe ...

2023

Hydrogen Intensity and Real-Time Analysis Experiment: 256-element array status and overview

Jean-Paul Richard Kneib, Martin Kunz, Emma Elizabeth Tolley, Zeyu Zhang, Carolyn Marie Crichton

The Hydrogen Intensity and Real-time Analysis Experiment (HIRAX) is a radio interferometer array currently in development, with an initial 256-element array to be deployed at the South African Radio Astronomy Observatory Square Kilometer Array site in Sout ...

SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS2022

Time-delay estimation in unresolved lensed quasars

Georgios Vernardos

Time-delay cosmography can be used to infer the Hubble parameter H-0 by measuring the relative time delays between multiple images of gravitationally lensed quasars. A few of such systems have already been used to measure H-0: Their time delays were determ ...

OXFORD UNIV PRESS2022

Multi-object spectroscopic operations with the Sloan Digital Sky Survey V

Luzius Gregor Kronig, Loïc Grossen, Ricardo Jorge Araùjo Pereira

The Sloan Digital Sky Survey V (SDSS-V) is an all-sky spectroscopic survey of more than 6 million objects, designed to decode the history of the Milky Way, reveal the inner workings of stars, investigate the origin of solar systems, and track the growth of ...

SPIE-INT SOC OPTICAL ENGINEERING2020

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

Molecular gas in distant brightest cluster galaxies

Gianluca Castignani

The mechanisms governing the stellar mass assembly and star formation history of brightest cluster galaxies (BCGs) are still being debated. By means of new and archival molecular gas observations we investigate the role of dense megaparsec-scale environmen ...

2020

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

Bayesian approach to SETI

Claudio Grimaldi

The search for technosignatures from hypothetical galactic civilizations is going through a new phase of intense activity. For the first time, a significant fraction of the vast search space is expected to be sampled in the foreseeable future, potentially ...

National Academy of Sciences2018

Meandering particle bunches and a link between averages of time series of particle counts and higher-order moments

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Marcelo Baquero Ruiz, Fabian Manke

Time-averaged spatially resolved measurements are used in many fields of physics to determine spatial distributions of a physical quantity. Although one could think that time averaging suppresses all information on time variation, there are some situations ...

2018

Development and Characterisation of Silicon Photomultiplier Multichannel Arrays for the Readout of a Large Scale Scintillating Fibre Tracker

Axel Kuonen

The current LHCb detector will continue collecting data until the long shutdown 2 (2019/2020). It will be upgraded in order to operate at higher luminosity. To achieve this, two major changes are required. First the Level-0 hardware trigger limited to 1,M ...

EPFL2018

Back-Propagating the Light of Field Stars to Probe Telescope Mirrors Aberrations

Michaël Unser, Frédéric Courbin, Ferréol Arnaud Marie Soulez

We propose a wavefront-based method to estimate the PSF over the whole field of view. This method estimate the aberrations of all the mirrors of the telescope using only field stars. In this proof of concept paper, we described the method and present some ...

SPIE2016

The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula

MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well a ...

Elsevier Science Bv2016

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

Johan Richard, Jean-Paul Richard Kneib, Hakim Atek, Mathilde Jauzac, 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

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses XIV. Time delay of the doubly lensed quasar SDSS J1001+5027

Malte Tewes, Georges Meylan, Frédéric Courbin

This paper presents optical R-band light curves and the time delay of the doubly imaged gravitationally lensed quasar SDSS J1001+5027 at a redshift of 1.838. We have observed this target for more than six years, between March 2005 and July 2011, using the ...

Edp Sciences S A2013

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

Mathieu Ribordy, Camille Haller, Thomas Günther Bretz, Werner Lustermann

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

Large Micromirror Array Based on a Scalable Technology for Astronomical Instrumentation

Michael David Canonica

Understanding the formation of galaxies and studying the expansion of the Universe, need the spectral characterization of faint astronomical objects such as stars or galaxies. From these spectra, the distance, the velocity and the chemical composition of t ...

EPFL2012

Searches for dark matter annihilation signatures in the Segue 1 satellite galaxy with the MAGIC-I telescope

Thomas Günther Bretz

We report the results of the observation of the nearly satellite galaxy Segue 1 performed by the MAGIC-I ground-based gamma-ray telescope between November 2008 and March 2009 for a total of 43.2 hours. No significant gamma-ray emission was found above the ...

2011

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

Gravitational lenses : time delays and the Hubble constant

Christel Vuissoz

The Hubble constant H0 is one of the most important parameters in cosmology, as it encodes the age of the Universe and is necessary for any distance determination at a cosmological scale. It is, however, only poorly constrained by traditional methods. The ...

EPFL2008

The Random Trip Model: Stability, Stationary Regime, and Perfect Simulation The Random Trip Model: Stability, Stationary Regime, and Perfect Simulation

Jean-Yves Le Boudec, Milan Vojnovic

We define "random trip", a generic mobility model for random, independent node motions, which contains as special cases: the random waypoint on convex or nonconvex domains, random walk on torus, billiards, city section, space graph, intercity and other mod ...

2006