Concept

Time-domain astronomy

Related publications (27)

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

Mathieu Ribordy, Werner Lustermann, 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 : 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

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