Related papers: Microlensing of Quasars
Strong lensing is a powerful tool to address three major astrophysical issues: understanding the spatial distribution of mass at kpc and sub-kpc scale, where baryons and dark matter interact to shape galaxies as we see them; determining the…
Gravitational lensing is brightening of background objects due to deflection of light by foreground sources. Rich clusters of galaxies are very effective lenses because they are centrally concentrated. Such natural Gravitational Telescopes…
The observed acceleration of the universe, explained through dark energy, could alternatively be explained through a modification of gravity that would also induce modifications in the evolution of cosmological perturbations. We use new…
Quasar microlensing flux ratios are used to unveil properties of the lenses in large collections of lensed quasars, like the ones expected to be produced by the Euclid survey. This is achieved by using the direct survey products, without…
We present a detailed study of the effects of gravitational microlensing on compact and distant $\gamma$-ray blazars. These objects have $\gamma$-ray emitting regions which are small enough as to be affected by microlensing effects produced…
X-ray and optical observations of quadruply lensed quasars can provide a microarcsecond probe of the lensed quasar, corresponding to scale sizes of \~10^2-10^4 gravitational radii of the central black hole. This high angular resolution is…
Basics of standard theory of microlensing are introduced. Results of microlensing observations toward Magellanic Clouds and relations with dark matter (DM) problem in our Galaxy are described. Pixel microlensing observations and recent…
We use numerical simulations to test a broad range of plausible observational strategies designed to measure the time delay between the images of gravitationally lensed quasars. Artificial quasar light curves are created along with…
Flux ratios of multiple images in strong gravitational lensing systems provide a powerful probe of dark matter substructure. Optical flux ratios of lensed quasars are typically affected by stellar microlensing, and thus studies of dark…
Quasar pairs are either physically distinct binary quasars or the result of gravitational lensing. The majority of known pairs are in fact lenses, with a few confirmed as binaries, leaving a population of objects that have not yet been…
The effect of gravitational microlensing on the intensity of gravitational radiation as it propagates through an inhomogeneous medium containing small-scale structure is considered. Lensing by both stars and a power law spectrum of density…
Gravitational weak lensing by large scale structures is view as a tool to probe the bias relation between the mass and the light distributions. It is explained how a particular statistic can be used to deproject the 2D mass distribution…
Weak gravitational lensing is one of the key probes of the cosmological model, dark energy, and dark matter, providing insight into both the cosmic expansion history and large scale structure growth history. Taking into account a broad…
Weak lensing by large scale structure or 'cosmic shear' is a potentially powerful cosmological probe to shed new light on Dark Matter, Dark Energy and Modified Gravity. It is based on the weak distortions induced by large-scale structures…
By comparing the results from numerical microlensing simulations to the observed long-term variability of quasars, strong upper limits on the cosmological density of compact objects in the 0.0001-1 solar mass range may in principle be…
Gravitational lensing has now become a popular tool to measure the mass distribution of structures in the Universe on various scales. Here we focus on the study of galaxy's scale dark matter halos with galaxy-galaxy lensing techniques:…
Weak gravitational lensing observations probe the spectrum and evolution of density fluctuations and the cosmological parameters which govern them. The non-linear evolution of large scale structure produces a non-Gaussian signal which is…
The uncertain origin of the recently-discovered `changing-looking' quasar phenomenon -- in which a luminous quasar dims significantly to a quiescent state in repeat spectroscopy over ~10 year timescales -- may present unexpected challenges…
Doppler lensing is the apparent change in object size and magnitude due to peculiar velocities. Objects falling into an overdensity appear larger on its near side, and smaller on its far side, than typical objects at the same redshifts.…
In order to investigate the dependence of quasar optical-UV variability on fundamental physical parameters like black hole mass, we have matched quasars from the QUEST1 variability survey with broad-lined objects from the SDSS. Black hole…