Results 41 to 50 of about 70,851 (245)

Gravitational Lens Time Delays Using Polarization Monitoring

Galaxies, 2017
Gravitational lens time delays provide a means of measuring the expansion of the Universe at high redshift (and therefore in the ‘Hubble flow’) that is independent of local calibrations.
Andrew Biggs, Ian Browne
doaj   +1 more source

Pixelated Reconstruction of Foreground Density and Background Surface Brightness in Gravitational Lensing Systems Using Recurrent Inference Machines

The Astrophysical Journal, 2023
Modeling strong gravitational lenses in order to quantify distortions in the images of background sources and to reconstruct the mass density in foreground lenses has been a difficult computational challenge.
Alexandre Adam, Laurence Perreault-Levasseur, Yashar Hezaveh, Max Welling   +3 more
doaj   +1 more source

Perturbative Approach to the Gravitational Lensing by a Non-spherically Distorted Compact Object

, 2011
We investigate the gravitational lens effect caused by a non-spherically distorted compact object. The non-spherical property of the gravitational potential is modeled by a quadrupole moment. Under the assumption that the quadrupole contribution is small,
Alard, Alard, Alard, Amano Saijo, Asada, Asada, Asada, Baraldo, Ebina, Ibanez, Konno, Mao, Masumi Kasai, Sari, Schneider   +14 more
core   +1 more source

First Observation of Parallax in a Gravitational Microlensing Event [PDF]

, 1995
We present the first detection of parallax effects in a gravitational microlensing event. Parallax in a gravitational microlensing event observed only from the Earth appears as a distortion of the lightcurve due to the motion of the Earth around the Sun.
A. W. Rodgers,, B. A. Peterson,, Benetti S., C. Alcock,, C. W. Stubbs,, D. Alves,, D. P. Bennett,, J. Guern,, K. C. Freeman,, K. Griest,, K. H. Cook,, M. J. Lehner,, M. R. Pratt,, P. J. Quinn,, R. A. Allsman,, Refsdal S., S. L. Marshall,, T. S. Axelrod,, Udalski A., Udalski A., W. Sutherland   +20 more
core   +2 more sources

The strong gravitational lens finding challenge [PDF]

Astronomy & Astrophysics, 2019
Large-scale imaging surveys will increase the number of galaxy-scale strong lensing candidates by maybe three orders of magnitudes beyond the number known today. Finding these rare objects will require picking them out of at least tens of millions of images, and deriving scientific results from them will require quantifying the efficiency and bias of ...
Metcalf, R. Benton, Meneghetti, M., Avestruz, Camille, Bellagamba, Fabio, Bom, Clécio R., Bertin, Emmanuel, Cabanac, Rémi, Courbin, F., Davies, Andrew, Decencière, Etienne, Flamary, Rémi, Gavazzi, Raphael, Geiger, Mario, Hartley, Philippa, Huertas-Company, Marc, Jackson, Neal, Jacobs, C., Jullo, Eric, Kneib, Jean-Paul, Koopmans, Léon V.E., Lanusse, François, Li, Chun-Liang, Ma, Quanbin, Makler, Martin, Li, Nan, Lightman, Matthew, Petrillo, Carlo Enrico, Serjeant, Stephen, Schäfer, Christoph, Sonnenfeld, Alessandro, Tagore, Amit, Tortora, Crescenzo, Tuccillo, Diego, Valentín, Manuel B., Velasco-Forero, Santiago, Verdoes Kleijn, Gijs A., Vernardos, Georgios   +36 more
openaire   +7 more sources

B0850+054: a new gravitational lens system from CLASS [PDF]

, 2002
We report the discovery of a new gravitational lens system from the CLASS survey. Radio observations with the VLA, the WSRT and MERLIN show that the radio source B0850+054 is comprised of two compact components with identical spectra, a separation of 0.7
A. C. S. Readhead, A. D. Biggs, A. G. De Bruyn, C. D. Fassnacht, Chae, D. Rusin, I. W. A. Browne, J. P. McKean, K.- H. Chae, L. V. E. Koopmans, M. A. Norbury, N. J. Jackson, P. M. Phillips, P. N. Wilkinson, R. D. Blandford, S. T. Myers, T. J. Pearson   +16 more
core   +3 more sources

IMAGES DISTRIBUTION OF BINARY SYMMETRICAL GRAVITATIONAL LENS

Odessa Astronomical Publications, 2019
In this paper, we study the distribu- tion of images from a point source in N - point gravi- tational lenses. It is well known that in a Schwarzschild lens (N = 1) from a point source, there are always two images.
A. T. Kotvytskiy, S. D. Bronza, V. Yu. Shablenko   +2 more
doaj   +1 more source

Self-consistent gravitational lens reconstruction [PDF]

Monthly Notices of the Royal Astronomical Society, 1998
We present a new method for directly determining accurate, self-consistent cluster lens mass and shear maps in the strong lensing regime from the magnification bias of background galaxies. The method relies upon pixellisation of the surface mass density distribution which allows us to write down a simple, solvable set of equations.
Dye, S., Taylor, A.
openaire   +2 more sources

Gravitational lens on de Sitter background

Physical Review D, 2022
Gravitational lenses are examined in de-Sitter (dS) background, for which the existence of the dS horizon is taken into account and hyperbolic trigonometry is used together with the hyperbolic angular diameter distance. Spherical trigonometry is used to discuss a gravitational lens in anti-de Sitter (AdS) background.
Keita Takizawa, Hideki Asada
openaire   +2 more sources

QUASI-ANALYTICAL METHOD FOR IMAGES CONSTRUCTION FROM GRAVITATIONAL LENSES

Odessa Astronomical Publications, 2016
One of the main problems in the study of system of equations of the gravitational lens, is the computation of coordinates from the known position of the source. In the process of computing finds the solution of equations with two unknowns. The problem is
A. T. Kotvytskiy, S. D. Bronza
doaj   +1 more source