English
Related papers

Related papers: A Targeted Search for Variable Gravitationally Len…

200 papers

We report new high-quality galaxy scale strong lens candidates found in the Kilo Degree Survey data release 4 using Machine Learning. We have developed a new Convolutional Neural Network (CNN) classifier to search for gravitational arcs,…

Current X-ray observations and simulations show that gravitational lensing can be used to infer the structure near the event horizons of black holes, constrain the dynamics and evolution of black-hole accretion and outflows, test general…

High Energy Astrophysical Phenomena · Physics 2019-04-04 George Chartas , Henric Krawczynski , David Pooley , Richard F. Mushotzky , Andrew J. Ptak

We have carried out a systematic search for galaxy-scale strong lenses in multiband imaging from the Hyper Suprime-Cam (HSC) survey. Our automated pipeline, based on realistic strong-lens simulations, deep neural network classification, and…

We report upon three years of follow-up and confirmation of doubly imaged quasar lenses through imaging campaigns from 2016-2018 with the Near-Infrared Camera2 (NIRC2) on the W. M. Keck Observatory. A sample of 57 quasar lens candidates are…

We present the discovery of 3 quasar lenses in the Sloan Digital Sky Survey (SDSS), selected using two novel photometry-based selection techniques. The J0941+0518 system, with two point sources separated by 5.46" on either side of a galaxy,…

Bright galaxy-galaxy strong lenses are much more powerful than lensed quasars for measuring the mass profiles of galaxies, but until this year only a handful have been known. Here we present five new examples, identified via the optimal…

Astrophysics · Physics 2009-11-11 J. P. Willis , P. C. Hewett , S. J. Warren , S. Dye , N. Maddox

We present preliminary results of the CIDA Equatorial Variability Survey (CEVS), looking for quasar (hereafter QSO) candidates near the Galactic plane. The CEVS contains photometric data from extended and adjacent regions of the Milky Way…

We present a sample of 12 quasar candidates with highly variable soft X-ray emission from the 4th XMM-newton Serendipitous Source Catalog (4XMM-DR13) using random forest. We obtained optical to mid-IR photometric data for the 4XMM-DR13…

Astrophysics of Galaxies · Physics 2025-05-16 Heng Wang , Yanli Ai , Yanxia Zhang , Yuming Fu , Wenfeng Wen , Liming Dou , Xue-Bing Wu , Xiangru Li , Zhiying Huo

We report the discovery of a new gravitational lens system. This object, ULAS J234311.93-005034.0, is the first to be selected by using the new UKIRT Infrared Deep Sky Survey (UKIDSS), together with the Sloan Digital Sky Survey (SDSS). The…

Astrophysics · Physics 2009-06-23 Neal Jackson , Eran O. Ofek , Masamune Oguri

We present RingFinder, a tool for finding galaxy-scale strong gravitational lenses in multiband imaging data. By construction, the method is sensitive to configurations involving a massive foreground early-type galaxy and a faint,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Raphael Gavazzi , Philip J. Marshall , Tommaso Treu , Alessandro Sonnenfeld

We performed an automated comparison of the FIRST radio survey with the APM optical catalog to find radio lobes with optical counterparts. Based on an initial survey covering ~3000 square degrees, we selected a sample of 33 lens candidates…

Astrophysics · Physics 2009-10-31 J. Lehar , A. Buchalter , R. G. McMahon , C. S. Kochanek , T. W. B. Muxlow

Gravitationally lensed quasars are valuable, but extremely rare, probes of observational cosmology and extragalactic astrophysics. Progress in these fields has been limited just by the paucity of systems with good ancillary data. Here we…

Astrophysics of Galaxies · Physics 2018-12-26 C. Spiniello , A. Agnello , A. V. Sergeyev , T. Anguita , Ó. Rodríguez , N. R. Napolitano , C. Tortora

We report the observation and confirmation of the first group- and cluster-scale strong gravitational lensing systems found in Dark Energy Survey (DES) data. Through visual inspection of data from the Science Verification (SV) season, we…

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…

We test the impact of gravitational lensing on the lifetime estimates of seven high-redshift quasars at redshift $z\gtrsim6$. The targeted quasars are identified by their small observed proximity zone sizes, which indicate extremely short…

We present a status report on our search for multiple-image QSOs among southern radio sources. Our goal is to identify new lenses for use in studies of cosmology and galaxy structure. To date we have examined 3300 radio sources, identified…

Astrophysics · Physics 2007-05-23 Joshua N. Winn , Jacqueline N. Hewitt , Paul L. Schechter

We report the discovery of a new quadruply imaged quasar surrounded by an optical Einstein ring candidate. Spectra of the different components of 1RXS J113155.4-123155 reveal a source at z=0.658. Up to now, this object is the closest known…

Gravitationally strongly lensed quasars (SL-QSO) offer invaluable insights into cosmological and astrophysical phenomena. With the data from ongoing and next-generation surveys, thousands of SL-QSO systems can be discovered expectedly,…

We present results of a systematic search for gravitationally lensed quasars in Pan-STARRS1. Our final sample of candidates comprises of 91 systems, not including 25 rediscovered lensed quasars and quasar pairs. In the absence of…

Data mining through large, multi-band ground-based surveys and the recent availability of source catalogues from the {\it Gaia} space mission has led to a surge in the number of known gravitationally lensed quasars, including some unusual…

Astrophysics of Galaxies · Physics 2018-10-02 Cristian E. Rusu , Cameron A. Lemon