Concept

Astronomie des phénomènes transitoires

Publications associées (34)

Microlensing of the broad line region in 17 lensed quasars

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

Superresolution Imaging using Single-Molecule Localization

Suliana Manley

Superresolution imaging is a rapidly emerging new field of microscopy that dramatically improves the spatial resolution of light microscopy by over an order of magnitude (similar to 10-20-nm resolution), allowing biological processes to be described at the ...

2010

Long-Term Monitoring Of Bright Blazars With A Dedicated Cherenkov Telescope

Werner Lustermann, Mathieu Ribordy, Thomas Günther Bretz

Flaring activity of Active Galactic Nuclei (AGN) in VHE gamma-ray astronomy is observed on timescales from minutes to years and can be explained either by the interaction of relativistic jets with the surrounding material or by imprints of the central engi ...

2009

Microlensing variability in the gravitationally lensed quasar QSO 2237+0305 equivalent to the Einstein Cross II. Energy profile of the accretion disk

Frédéric Courbin, Georges Meylan, Alexander Patrick Eigenbrod

We present the continuation of our long-term spectroscopic monitoring of the gravitationally lensed quasar QSO 2237 + 0305. We investigate the chromatic variations observed in the UV/optical continuum of both quasar images A and B, and compare them with nu ...

2008

COSMOGRAIL: the COSmological MOnitoring of GRAvItational lenses - VII. Time delays and the Hubble constant from WFI J2033-4723

Frédéric Courbin, Georges Meylan, Christel Vuissoz

Gravitationally lensed quasars can be used to map the mass distribution in lensing galaxies and to estimate the Hubble constant H-0 by measuring the time delays between the quasar images. Here we report the measurement of two independent time delays in the ...

2008

Microlensing variability in the gravitationally lensed quasar QSO 2237+0305 equivalent to the Einstein Cross - I. Spectrophotometric monitoring with the VLT

Frédéric Courbin, Georges Meylan, Alexander Patrick Eigenbrod

We present the results of the first long-term (2.2 years) spectroscopic monitoring of a gravitationally lensed quasar, namely the Einstein Cross QSO 2237+0305. The goal of this paper is to present the observational facts to be compared in follow-up papers ...

2008

Ultrafast nonresonant response of TiO2 nanostructured films

Majed Chergui, Frank van Mourik, Erwin Portuondo Campa

The authors present a detailed study of the nonresonant 3rd-order ultrafast response of TiO2 nanostructured films, combining a classical heterodyned optical Kerr effect expt., with 2 polarization selective Kerr techniques, based on transient lensing and ph ...

2008

Gravitational lenses

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

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