Related papers: First Resolution of Microlensed Images
Massive galactic lenses with large Einstein Radii should cause a measurable astrometric microlensing effect, i.e. the light centroid shift due to the motion of the two images. Such a shift in the position of a background star due to…
Measurement of the time delay between multiple images of a gravitational lens system is potentially an accurate method of determining the Hubble constant over cosmological distances. One of the most promising candidates for an application…
Strong gravitational lensing from black holes results in the formation of relativistic images, in particular, relativistic Einstein rings. For objects with event horizons, the radius of the unstable light ring (photon sphere) is the lowest…
The properties of light in the presence of electromagnetic and gravitational fields are compared. Once one takes account of the fact that clock rates vary with distance from a massive object, it is argued that in an absolute sense light…
Gravitational microlensing occurs when a foreground star happens to pass very close to our line of sight to a more distant background star. The foreground star acts as a lens, splitting the light from the source star into two images, which…
We have discovered a new gravitational lens in the Cosmic Lens All-Sky Survey (CLASS). B2045+265 is a four-image system with a maximum separation of 1.9 arcsec. A fifth radio component is detected, but its radio spectrum and its positional…
The remarkably strong radio gravitational lens PKS 1830-211 consists of a one arcsecond diameter Einstein ring with two bright compact (milliarcsecond) components located on opposite sides of the ring. We have obtained 22 GHz VLBA data on…
The statistics of Einstein radii for a sample of strong lenses can provide valuable constraints on the underlying mass distribution. The correct interpretation, however, relies critically on the modelling of the selection of the sample,…
The gravitational microlensing light curves that reveal the presence of extrasolar planets generally yield the planet-star mass ratio and separation in units of the Einstein ring radius. The microlensing method does not require the…
We have measured a time delay of 25.3 +/- 2.0 d (1-sigma confidence) in the Einstein ring gravitational lens system PKS 1830-211 from an analysis of archival VLA and ATCA monitoring data observed between 1997 and 2004. A small portion of…
In the era of large surveys, yielding thousands of galaxy clusters, efficient mass proxies at all scales are necessary in order to fully utilize clusters as cosmological probes. At the cores of strong lensing clusters, the Einstein radius…
We report the result of the analysis of the light curve of the microlensing event MOA-2009-BLG-016. The light curve is characterized by a short-duration anomaly near the peak and an overall asymmetry. We find that the peak anomaly is due to…
Gravitational-wave astronomy allows us to study objects and events invisible to electromagnetic waves. So far, only signals triggered by coalescing binaries have been detected. However, as the interferometers' sensitivities improve over…
We present the first unambiguous case of external variability of a radio gravitational lens, CLASS B1600+434. The VLA 8.5-GHz difference light curve of the lensed images, taking the proper time-delay into account, shows the presence of…
We propose a new method to test the cosmic distance duality relation using the strongly lensed gravitational waves. The simultaneous observations of image positions, the relative time delay between different images, the redshift…
We analyzed the Einstein radius, $\theta_E$, in our sample of SL2S galaxy groups, and compared it with $R_A$ (the distance from the arcs to the center of the lens), using three different approaches: 1.- the velocity dispersion obtained from…
Interferometric measurements of optical path length differences of stars over large baselines can deliver extremely accurate astrometric data. The interferometer GRAVITY will simultaneously measure two objects in the field of view of the…
We investigated binary lens events from the 2022-2024 microlensing surveys, aiming to identify events suitable for lens mass measurements. We focused on two key light curve features: distinct caustic spikes with resolved crossings for…
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…
We report the discovery of a new two-image gravitational lens system from the Cosmic Lens All-Sky Survey, CLASS B2319+051. Radio imaging with the Very Large Array (VLA) and Multi-Element Radio-Linked Interferometer Network (MERLIN) shows…