Related papers: Using the 6dF galaxy redshift survey to detect gra…

Strong gravitational lensing enables a wide range of science: probing cosmography; testing dark matter models; understanding galaxy evolution; and magnifying the faint, small and distant Universe. However to date exploiting strong lensing…

We present the discovery of three new quasars at z>6 in 1300 deg^2 of SDSS imaging data, J114816.64+525150.3 (z=6.43), J104845.05+463718.3 (z=6.23) and J163033.90+401209.6 (z=6.05). The first two objects have weak Ly alpha emission lines;…

Combining the exquisite angular resolution of Gaia with optical light curves and WISE photometry, the Gaia Gravitational Lenses group (GraL) uses machine learning techniques to identify candidate strongly lensed quasars, and has confirmed…

Gravitational microlensing of quasars by stars in external galaxies can introduce fluctuations in the centroid of the ``point-like'' macro--images. The induced shifts are extremely small, on micro--arcsecond scales, below the limits of…

We report the discovery of a new gravitationally lensed quasar from the Sloan Digital Sky Survey, SDSS J092455.87+021924.9 (SDSS J0924+0219). This object was selected from among known SDSS quasars by an algorithm that was designed to select…

We have observed a sample of 15 and 8 quasars with redshifts between 0.11 and 0.87 (mean value 0.38) in the J and K' bands respectively. Eleven of the quasars were previously known to be associated with extended emission line regions. After…

We report the discovery of a new two-image gravitationally lensed quasar, SDSS J024634.11-082536.2 (SDSS J0246-0825). This object was selected as a lensed quasar candidate from the Sloan Digital Sky Survey (SDSS) by the same algorithm that…

Bright gravitationally lensed galaxies provide our most detailed view of galaxies at high redshift. Yet as a result of the small number of ultra-bright z~2 lensed systems with confirmed redshifts, most detailed spectroscopic studies have…

The dark halo substructures predicted by current cold dark matter simulations may in principle be detectable through strong-lensing image splitting of quasars on small angular scales (0.01 arcseconds or below). Here, we estimate the overall…

Lensed quasars are powerful probes of cosmology, the co-evolution of supermassive black holes and their host galaxies, and the distribution of dark matter. We cross-match 1,724 previously identified candidates from KiDS, HSC, and the DESI…

We report that the Sloan Digital Sky Survey quasar SDSS J165043.44+425149.3 is gravitationally lensed into two images, based on observations obtained with the WIYN 3.5 m telescope at the Kitt Peak National Observatory. The lensed quasar, at…

We present results from a systematic search for strong gravitational lenses in the GOODS ACS data. The search technique involves creating a sample of likely lensing galaxies, which we define as massive early-type galaxies in a redshift…

We report the discovery of a gravitationally lensed quasar identified serendipitously in the Sloan Digital Sky Survey (SDSS). The object, SDSS J094604.90+183541.8, was initially targeted for spectroscopy as a luminous red galaxy, but the…

(abridged) Gravitationally lensed quasars can be used as powerful cosmological and astrophysical probes. We can (i) infer the Hubble constant based on the time-delay technique, (ii) unveil substructures along the l.o.s. toward distant…

We report the discovery of two doubly-imaged quasars, SDSS J100128.61+502756.9 and SDSS J120629.65+433217.6, at redshifts of 1.838 and 1.789 and with image separations of 2.86'' and 2.90'', respectively. The objects were selected as lens…

Chandra snapshot observations of the three most distant quasars then known, at redshifts 5.82, 5.99, and 6.28, gave signficant detections even in the short, 6 -- 8 ks, observations. The X-ray to optical luminosity ratios indicate that…

We report the discovery of a unique gravitational lens system, SDSSJ2222+2745, producing five spectroscopically confirmed images of a z_s=2.82 quasar lensed by a foreground galaxy cluster at z_l=0.49. We also present photometric and…

We present the final statistical sample of lensed quasars from the Sloan Digital Sky Survey (SDSS) Quasar Lens Search (SQLS). The well-defined statistical lens sample consists of 26 lensed quasars brighter than i=19.1 and in the redshift…

We present a new method to search for strong gravitational lensing systems by pairing spectra that are close together on the sky in a spectroscopic survey. We visually inspect 26,621 spectra in the Dark Energy Spectroscopic Instrument…

Gravitationally lensed quasars are useful for studying astrophysics and cosmology, and enlarging the sample size of lensed quasars is important for multiple studies. In this work, we develop a lens search algorithm for four-image (quad)…