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Related papers: Cosmological nanolensing by dense gas clouds

200 papers

A long standing question in cosmology is whether gravitational lensing changes the distance-redshift relation $D(z)$ or the mean flux density of sources. Interest in this has been rekindled by recent studies in non-linear relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-16 Nick Kaiser , John A. Peacock

We present limits on the cosmological constant from the statistics of gravitational lenses using newly completed quasar surveys, new lens data, and a range of lens models. The formal limit is $\lambda_0 < 0.66$ at 95\% confidence in flat…

Astrophysics · Physics 2009-10-28 C. S. Kochanek

We present a new sample of purely near infra-red selected KVega<16.5 extremely red ((J-K)>2.5) quasar candidates at z~2 from 900 sq deg of data in the UKIDSS Large Area Survey (LAS). Five of these are spectroscopically confirmed to be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Manda Banerji , Richard G. McMahon , Paul C. Hewett , Susannah Alaghband-Zadeh , Eduardo Gonzalez-Solares , Bram P. Venemans

We use archival data of NASA's Chandra X-ray telescope to compile an X-ray light curve of all four images of the quadruply lensed quasar Q2237+0305 (z=1.695) from January 2006 to January 2007. We fit simulated point spread functions to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 F. Zimmer , R. W. Schmidt , J. Wambsganss

We use a series of ray-tracing experiments to determine the magnification distribution of high-redshift sources by gravitational lensing. We determine empirically the relation between magnification and redshift, for various cosmological…

Astrophysics · Physics 2007-05-23 Premana Premadi , Hugo Martel

Observational evidence shows that gravitational lensing induces an angular correlation between the distribution of galaxies and much more distant QSOs. We use weak gravitational lensing theory to calculate this angular correlation, updating…

We consider the geometrical optics for refraction of a distant radio source by an interstellar plasma lens, with application to a lens with a Gaussian electron column density profile. The refractive properties of the lens are specified…

Astrophysics · Physics 2009-10-30 Andrew W. Clegg , Alan L. Fey , T. Joseph W. Lazio

The statistics of gravitationally lensed quasars with multiple images in the 0.1''-7'' range have been measured in various surveys. Little is known, however, about lensed-quasar statistics at larger image separations, which probe masses on…

Astrophysics · Physics 2009-10-28 Dan Maoz , Hans-Walter Rix , Avishay Gal-Yam , Andrew Gould

Hard X-ray surveys have uncovered a large population of heavily obscured AGN. They also reveal a population of quasars with moderate obscuration at both visible and X-ray wavelengths. We use Chandra selected samples of quasars from the…

We present a simple gravitational lens model to illustrate the ease of using the embedded lensing theory when studying cosmic voids. It confirms the previously used repulsive lensing models for deep voids. We start by estimating magnitude…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-17 Bin Chen , Ronald Kantowski , Xinyu Dai

In this work, we study the interaction of the electromagnetic wave (EW) from a distant quasar with the gravitational wave (GW) sourced by the binary stars. While in the regime of geometric optics, the light bending due to this interaction…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-13 Sohrab Rahvar

Gravitational lensing can amplify the apparent brightness of distant sources. Images that are highly magnified are often part of multiply-imaged systems, but we consider the possibility of having large magnifications without additional…

Astrophysics · Physics 2009-11-10 Charles R. Keeton , Michael Kuhlen , Zoltan Haiman

We show that by analyzing the spectra of lensed broad absorption line quasars (BALQSOs), it is possible to reveal key properties of the outflowing gas in the inner regions of these objects. This results from the fact that each image of the…

Astrophysics · Physics 2009-11-10 Doron Chelouche

Numerical simulations and theoretical studies of the gravitational microlensing effect of a population of small bodies distributed along the line of sight to a compact light source such as a quasar indicate that caustic crossing effects…

Astrophysics · Physics 2007-05-23 M. R. S. Hawkins

We investigate the possibility of measuring the Hubble constant, the fractional energy density components and the equation of state parameter of the ``dark energy'' using lensed multiple images of high-redshift supernovae. With future…

Astrophysics · Physics 2009-11-07 A. Goobar , E. Mortsell , R. Amanullah , P. Nugent

We demonstrate that gravitationally lensed quasars are easily recognized using image subtraction methods as time variable sources that are spatially extended. For Galactic latitudes |b|>20 deg, lensed quasars dominate the population of…

Astrophysics · Physics 2009-11-13 C. S. Kochanek , B. Mochejska , N. D. Morgan , K. Z. Stanek

We study the wave optics features of gravitational microlensing by a binary lens composed of a planet and a parent star. In this system, the source star near the caustic line produces a pair of images in which they can play the role of…

Earth and Planetary Astrophysics · Physics 2015-06-05 Ahmad Mehrabi , Sohrab Rahvar

The scatter in the apparent magnitude of type Ia supernovae induced by stochastic gravitational lensing is highly dependent on the nonlinear growth of cosmological structure. In this paper, we show that such a dependence can potentially be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Cosimo Fedeli , Lauro Moscardini

We present a quantitative analysis of the effect of microlensing caused by random motion of individual stars in the galaxy which is lensing a background quasar. We calculate a large number of magnification patterns for positions of the…

Astrophysics · Physics 2016-08-30 Joachim Wambsganss , Tomislav Kundic

We use the high magnification event seen in the 1999 OGLE campaign light curve of image C of the quadruply imaged gravitational lens Q2237+0305 to study the structure of the quasar engine. We have obtained g'- and r'-band photometry at the…