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Concept

Time-domain astronomy

Related publications (27)

Accretion Disk Size and Updated Time-delay Measurements in the Gravitationally Lensed Quasar SDSS J165043.44+425149.3

Frédéric Courbin, Martin Raoul Robert Millon

We analyze variability in 15-season optical lightcurves from the doubly imaged lensed quasar SDSS J165043.44+425149.3 (SDSS1650), comprising five seasons of monitoring data from the Maidanak Observatory (277 nights in total, including the two seasons of da ...

Iop Publishing Ltd2024

Resolving the vicinity of supermassive black holes with gravitational microlensing

Georgios Vernardos

Upcoming wide-field surveys will discover thousands of new strongly lensed quasars which will be monitored with unprecedented cadence by the Legacy Survey of Space and Time (LSST). Many of these quasars will undergo caustic-crossing events over the 10-yr L ...

Oxford Univ Press2024

Probing compact dark matter objects with microlensing in gravitationally lensed quasars

Frédéric Courbin, Martin Raoul Robert Millon, Hung-Hsu Chan, Eric Gérard Guy Paic

The microlensing signal in the light curves of gravitationally lensed quasars can shed light on the dark matter (DM) composition in their lensing galaxies. Here, we investigate a sample of six lensed quasars from the most recent and best COSMOGRAIL observa ...

EDP SCIENCES S A2023

Strong and micro lensing in distant quasars

Eric Gérard Guy Paic

Most large galaxies contain Super Massive Black Holes at their centers, drawing matter nearby to form swirling accretion disks emitting electromagnetic radiation. These are Active Galactic Nuclei. The brightest quasars are the most luminous Universe object ...

EPFL2023

Gaia Data Release 3: The extragalactic content

Richard Irving Anderson, Shuangqing Liao, Mária Süveges, Pablo Jose Fernandez Marcos

The Gaia Galactic survey mission is designed and optimized to obtain astrometry, photometry, and spectroscopy of nearly two billion stars in our Galaxy. Yet as an all-sky multi-epoch survey, Gaia also observes several million extragalactic objects down to ...

2023

Euclid preparation - XXIII. Derivation of galaxy physical properties with deep machine learning using mock fluxes and H-band images

Maurizio Martinelli, Robin Humphry-Baker, Frédéric Courbin, Georges Meylan, Gianluca Castignani, Austin Chandler Peel

Next-generation telescopes, like Euclid, Rubin/LSST, and Roman, will open new windows on the Universe, allowing us to infer physical properties for tens of millions of galaxies. Machine-learning methods are increasingly becoming the most efficient tools to ...

OXFORD UNIV PRESS2023

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

Constraining quasar structure using high-frequency microlensing variations and continuum reverberation

Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon, Hung-Hsu Chan, Georgios Vernardos, Eric Gérard Guy Paic

Gravitational microlensing is a powerful tool for probing the inner structure of strongly lensed quasars and for constraining parameters of the stellar mass function of lens galaxies. This is achieved by analysing microlensing light curves between the mult ...

EDP SCIENCES S A2022

Simulating time-varying strong lenses

Georgios Vernardos

We present a self-consistent and versatile forward modelling software package that can produce time series and pixel-level simulations of time-varying strongly lensed systems. The time dimension, which needs to take into account different physical mechanis ...

OXFORD UNIV PRESS2022

LSST: From Science Drivers to Reference Design and Anticipated Data Products

David Atienza Alonso, Jonathan Andrew Blazek, Darong Huang, Shahram Khazaei

We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the solar system, ex ...

IOP PUBLISHING LTD2019

Detecting shocked intergalactic gas with X-ray and radio observations

Claudio Gheller

Detecting the thermal and non-thermal emission from the shocked cosmic gas surrounding large-scale structures represents a challenge for observations, as well as a unique window into the physics of the warm-hot intergalactic medium. In this work, we presen ...

EDP SCIENCES S A2019

Impact of the 3D source geometry on time-delay measurements of lensed type-Ia supernovae

Frédéric Courbin, Hung-Hsu Chan, Vivien François Bonvin, Martin Raoul Robert Millon, Elodie Marie Charlène Savary, Olga Tihhonova

It has recently been proposed that gravitationally lensed type-Ia supernovae can provide microlensing-free time-delay measurements provided that the measurement is taken during the achromatic expansion phase of the explosion and that color light curves are ...

EDP SCIENCES S A2019

Accretion Disk Size Measurement and Time Delays in the Lensed Quasar WFI 2033-4723

Frédéric Courbin, Vivien François Bonvin

We present 13 seasons of R-band photometry of the quadruply lensed quasarWFI 2033-4723 from the 1.3m SMARTS telescope at CTIO and the 1.2m Euler Swiss Telescope at La Silla, in which we detect microlensing variability of similar to 0.2mag on a timescale of ...

IOP PUBLISHING LTD2018

The Time-Domain Spectroscopic Survey: Understanding The Optically Variable Sky With Sequels In Sdss-Iii

Jean-Paul Richard Kneib

The Time-Domain Spectroscopic Survey (TDSS) is an SDSS-IV eBOSS subproject primarily aimed at obtaining identification spectra of similar to 220,000 optically variable objects systematically selected from SDSS/Pan-STARRS1 multi-epoch imaging. We present a ...

Iop Publishing Ltd2016

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

A Consistent Picture Emerges: A Compact X-Ray Continuum Emission Region In The Gravitationally Lensed Quasar Sdss J0924+0219

Frédéric Courbin, Georges Meylan, Malte Tewes

We analyze the optical, UV, and X-ray microlensing variability of the lensed quasar SDSS J0924+ 0219 using six epochs of Chandra data in two energy bands (spanning 0.4-8.0 keV, or 1-20 keV in the quasar rest frame), 10 epochs of F275W (rest-frame 1089 angs ...

American Astronomical Society2015

FACT - The First G-APD Cherenkov Telescope (first results)

Mathieu Ribordy, Thomas Günther Bretz

In October 2011, the first air-Cherenkov telescope utilizing Geiger-mode avalanche photodiodes commenced operations. The silicon-based devices display several advantages compared to classical photomultiplier tubes allowing for a more compact camera design ...

Amer Inst Physics2012

Microlensing of the broad line region in 17 lensed quasars

Frédéric Courbin, Georges Meylan

When an image of a strongly lensed quasar is microlensed, the different components of its spectrum are expected to be differentially magnified owing to the different sizes of the corresponding emitting region. Chromatic changes are expected to be observed ...

Edp Sciences S A2012

Further Evidence That Quasar X-Ray Emitting Regions Are Compact: X-Ray And Optical Microlensing In The Lensed Quasar Q J0158-4325

Frédéric Courbin, Georges Meylan, Malte Tewes

We present four new seasons of optical monitoring data and six epochs of X-ray photometry for the doubly imaged lensed quasar Q J0158-4325. The high-amplitude, short-period microlensing variability for which this system is known has historically precluded ...

Iop Publishing Ltd2012

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