Related papers: QSO-Galaxy Association and Gravitational Lensing
We analyze the seldomly discussed lensing effects expected in low-z clusters (z = 0.05-0.15), using as an example the bright arc (z=0.073) discovered by Campusano and Hardy(1996) near the dominant cD galaxy of the cluster Abell 3408…
Paczy\'nski (1986) suggested that ``dark" objects in the halo of our Galaxy could enhance the luminosity of foreground stars, acting as gravitational microlenses. Such events has been recently reported by different collaborations. We assume…
Cosmological cluster-scale strong gravitational lensing probes the mass distribution of the dense cores of massive dark matter halos and the structures along the line of sight from background sources to the observer. It is frequently…
It is accepted that quasars are powered by supermassive black holes (SMBH) with masses in the range 10^6 - 10^9 solar masses in their cores. Occasionally, compact stars can plunge into SMBH. In addition, there may be a number of such…
The observed properties of high redshift galaxies depend on the underlying foreground distribution of large scale structure, which distorts their intrinsic properties via gravitational lensing. We focus on the regime where the dominant…
Gravitational lensing is a powerful tool to detect compact matter on very different mass scales. Of particular importance is the fact that lensing is sensitive to both luminous and dark matter alike. Depending on the mass scale, all lensing…
Galactic sized gravitational lenses are simulated by combining a cosmological N-body simulation and models for the baryonic component of the galaxy. The lens caustics, critical curves, image locations and magnification ratios are calculated…
We report a significant detection of weak, tangential distortion of the images of cosmologically distant, faint galaxies due to gravitational lensing by foreground galaxies. A mean image polarisation of $<p>=0.011\pm 0.006$ is measured for…
The magnification effect due to gravitational lensing enhances the chances of detecting moderate-redshift ($z \sim 1$) sources in very-high-energy (VHE; $E > 100$ GeV) $\gamma$-rays by ground-based Atmospheric Cherenkov Telescope…
We use simulated merger trees of galaxy-cluster halos to study the effect of the halo concentration distribution on strong lensing and X-ray emission. Its log-normal shape typically found in simulations favors outliers with high…
Spatial correlations of the observed sizes and luminosities of galaxies can be used to estimate the magnification that arises through weak gravitational lensing. However, the intrinsic prop- erties of galaxies can be similarly correlated…
We study lens statistics in flat, low-density universes with different equations of state $w=p_Q/\rho_Q$ for the dark energy component. Dark energy modifies the distance-redshift relation and the mass function of dark matter halos leading…
In gravitational lensing, the magnification effect changes the luminosity and size of a background galaxy. If the image sizes are not small compared to the scale over which the magnification and shear vary, higher-order distortions occur…
Measured time delays between the images of a gravitationally lensed source can lead to a determination of the Hubble constant ($H_o$), but only if the lensing mass distribution is well understood. The inability to sufficiently constrain…
We study gravitational lensing of the cosmic neutrino background. This signal is undetectable for the foreseeable future, but there is a rich trove of information available. At least some of the neutrinos from the early universe will be…
The last decade has shown a considerable development of gravitational lensing for cosmology because it probes the amount and the nature of dark matter, and provides information on the density parameter $\Omega$, the cosmological constant…
The quasar Q1208+1011 (z_{em}=3.8) is the second highest redshift double quasar ever detected. Several indications point toward it being a gravitational lensed system, although a definitive proof is still lacking. We present new evidence of…
Astrophysical black holes are likely to be surrounded by various forms of matter in the form of disks or halos. While a number of studies have examined the impact of an environment on the lensing of light or gravitational waves from…
We present evidence of the gravitational lensing of the cosmic microwave background by $10^{13}$ solar mass dark matter halos. Lensing convergence maps from the Atacama Cosmology Telescope Polarimeter (ACTPol) are stacked at the positions…
The aim of this paper is to investigate the claim that stars in the lensing galaxy of a gravitationally lensed quasar system can always account for the observed microlensing of the individual quasar images. A small sample of gravitationally…