Related papers: A Simple Method To Find All Lensed Quasars
If the unexpectedly high frequency of quasar pairs with very different component redshifts is due to the lensing of a population of background quasars by the foreground quasar, typical lens masses must be $\sim10^{12}M_{\sun}$ and the sum…
Strong gravitational lensing provides a powerful probe of the physical properties of quasars and their host galaxies. A high fraction of the most luminous high-redshift quasars was predicted to be lensed due to magnification bias. However,…
We present spectroscopic observations of six optical counterparts of intermediate luminosity X-ray sources (ULXs) around nearby galaxies. The spectra of the six objects show the presence of broad emission features. The identification of…
The distribution function of quasars with respect to apparent brightness is given, found under the assumption that quasars are, at least partially, the gravitationally enhanced images of the active nuclei of distant galaxies. A Schechter…
We demonstrate that gravitational lensing can be used to discover and study planets in the habitable zones of nearby dwarf stars. If appropriate software is developed, a new generation of monitoring programs will automatically conduct a…
Strong lenses are extremely useful probes of the distribution of matter on galaxy and cluster scales at cosmological distances, but are rare and difficult to find. The number of currently known lenses is on the order of 1,000. We wish to…
The light we observe from distant astrophysical objects including supernovae and quasars allows us to determine large distances in terms of a cosmological model. Despite the success of the standard cosmological model in fitting the data,…
We report the discovery of the two-image gravitationally lensed quasar SDSS J133222.62+034739.9 (SDSS J1332+0347) with an image separation of Delta_theta=1.14". This system consists of a source quasar at z_s=1.445 and a lens galaxy at…
The cosmic curvature, a fundamental parameter for cosmology could hold deep clues to inflation and cosmic origins. We propose an improved model-independent method to constrain the cosmic curvature by combining the constructed Hubble diagram…
We apply the iterative MCS deconvolution method (ISMCS) to near-IR HST archives data of seven gravitationally lensed quasars currently monitored by the COSMOGRAIL collaboration: HE 0047-1756, RX J1131-1231, SDSS J1138+0314, SDSS J1155+6346,…
Discovery of strongly-lensed gravitational wave (GW) sources will unveil binary compact objects at higher redshifts and lower intrinsic luminosities than is possible without lensing. Such systems will yield unprecedented constraints on the…
We have scanned 5000 deg$^{2}$ of Southern Sky to search for strongly lensed quasars with five methods, all source-oriented, but based on different assumptions and selection criteria. We analyse morphological searches based on Gaia…
Gravitational lensing of background compact objects like active galactic nuclei and quasars, by extended intermediate mass lenses such as globular clusters and and dark matter clumps with masses 10^5 - 10^8 M_sun, is considered. It is shown…
When light from a distant source object, like a galaxy or a supernova, travels towards us, it is deflected by massive objects that lie on its path. When the mass density of the deflecting object exceeds a certain threshold, multiple, highly…
This paper argues that there is a large population of dark galaxies which reveals its presence by the gravitational lensing of quasars, and outnumbers normal galaxies by around 3:1. There are 8 double quasars with a separation greater than…
Quasar samples remain severely incomplete at low Galactic latitudes because of strong extinction and source confusion. We conduct a systematic search for quasars behind the Galactic plane using X-ray sources from the Chandra Source Catalog…
We report the quadruple nature of the source WISE 025942.9-163543 as observed in the VST-ATLAS survey. Spectra of the two brightest images show quasar emission lines at z=2.16. The system was discovered by splitting ATLAS "cutouts" of WISE…
There are $\sim 1$, 0.1 and 0.01 gravitationally lensed X-ray sources per square degree with soft X-ray fluxes exceeding $10^{-15}, 10^{-14}$ and $10^{-13} ergs/s cm^{-2}$ respectively. These sources will be detected serendipitously with…
More than $200$ quasars have been detected so far at $z > 6$, with only one showing clear signs of strong gravitational lensing. Some studies call for a missing population of lensed high-$z$ quasars, but their existence is still in doubt. A…
We present variability and multi-wavelength photometric information for the 933 known quasars in the QUEST Variability Survey. These quasars are grouped into variable and non-variable populations based on measured variability confidence…