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Related papers: Time delay estimation in unresolved lensed quasars

200 papers

Aims: Our aim is to measure the time delay between the two gravitationally lensed images of the z = 1.547 quasar SDSS J1650+4251, in order to estimate the Hubble constant H_0. Methods: Our measurement is based on R-band light curves with 57…

Time-delay cosmography in strongly lensed quasars offer an independent way of measuring the Hubble constant, $H_0$. However, it has been proposed that the combination of microlensing and source-size effects, also known as microlensing time…

Astrophysics of Galaxies · Physics 2021-03-24 J. H. H. Chan , K. Rojas , M. Millon , F. Courbin , V. Bonvin , G. Jauffret

We test the robustness of published time delays for 11 lensed quasars by using two techniques to measure time shifts in their light curves. We chose to use two fundamentally different techniques to determine time delays in gravitationally…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-26 Eva Eulaers , Pierre Magain

Strong lensing gravitational time delays are a powerful and cost effective probe of dark energy. Recent studies have shown that a single lens can provide a distance measurement with 6-7 % accuracy (including random and systematic…

(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…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-05 D. Sluse , V. Chantry , P. Magain , F. Courbin , G. Meylan

Strongly lensed quasar systems with time delay measurements provide "time delay distances", which are a combination of three angular diameter distances and serve as powerful tools to determine the Hubble constant $H_0$. However, current…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-18 Kai Liao , Arman Shafieloo , Ryan E. Keeley , Eric V. Linder

Strong gravitational lenses with measured time delay are a powerful tool to measure cosmological parameters, especially the Hubble constant ($H_0$). Recent studies show that by combining just three multiply-imaged AGN systems, one can…

The Hubble constant value is currently known to 10% accuracy unless assumptions are made for the cosmology (Sandage et al. 2006). Gravitational lens systems provide another probe of the Hubble constant using time delay measurements.…

Instrumentation and Methods for Astrophysics · Physics 2010-12-01 G. Gürkan , N. Jackson , I. W. A. Browne , L. V. E. Koopmans , C. D. Fassnacht , A. Berciano Alba

Time delays between lensed multiple images have been known to provide an interesting probe of the Hubble constant, but such application is often limited by degeneracies with the shape of lens potentials. We propose a new statistical…

Astrophysics · Physics 2008-11-26 Masamune Oguri

With the distance sum rule in the Friedmann-Lema\^{\i}tre-Robertson-Walker metric, model-independent constraints on both the Hubble constant $H_0$ and spatial curvature $\Omega_{K}$ can be obtained using strong lensing time-delay data and…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-22 Jun-Jie Wei , Fulvio Melia

Gravitationally lensed quasars offer a unique opportunity to study cosmological and extragalactic phenomena, using reliable light curves of the lensed images. This requires accurate deblending of the quasar images, which is not trivial due…

Instrumentation and Methods for Astrophysics · Physics 2025-04-24 Favio Neira , Frédéric Courbin , Frédéric Dux , Georgios Vernardos

One application of the Cosmological Gravitational Lensing in General Relativity is the measurement of the Hubble constant H_0 using the time delay Delta t between multiple images of lensed quasars. This method has already been applied,…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-27 Nicola Alchera , Marco Bonici , Nicola Maggiore

Strong gravitational lensing of variable sources, such as quasars or supernovae, can be used to constrain cosmological parameters through a technique known as "time-delay cosmography''. Competitive constraints on the Hubble constant have…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-10 Simon Birrer , Graham P. Smith , Anowar J. Shajib , Dan Ryczanowski , Nikki Arendse

A method for determining the time delays in gravitationally lensed quasars is proposed, which offers a simple and transparent procedure to mitigate the effects of microlensing. The method is based on fundamental properties of representation…

Instrumentation and Methods for Astrophysics · Physics 2018-02-09 V. S. Tsvetkova , V. M. Shulga , L. A. Berdina

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)…

In recent years, breakthroughs in methods and data have enabled gravitational time delays to emerge as a very powerful tool to measure the Hubble constant $H_0$. However, published state-of-the-art analyses require of order 1 year of expert…

We present a new method to estimate time delays from light curves of lensed quasars. The method is based on chi^2 minimization between the data and a numerical model light curve. A linear variation can be included in order to correct for…

Astrophysics · Physics 2007-05-23 I. Burud , P. Magain , S. Sohy , J. Hjorth

Tension between cosmic microwave background-based and distance ladder-based determinations of the Hubble constant ${\rm H}_{\rm 0}$ motivates pursuit of independent methods that are not subject to the same systematic effects. A promising…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-23 Kate Napier , Keren Sharon , Håkon Dahle , Matthew Bayliss , Michael D. Gladders , Guillaume Mahler , Jane R. Rigby , Michael Florian

We study the problem of estimating the time delay between two signals representing delayed, irregularly sampled and noisy versions of the same underlying pattern. We propose and demonstrate an evolutionary algorithm for the (hyper)parameter…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-27 Juan C. Cuevas-Tello , Peter Tino , Somak Raychaudhury , Xin Yao , Markus Harva

Time-delay cosmography of lensed quasars has achieved 2.4% precision on the measurement of the Hubble constant, $H_0$. As part of an ongoing effort to uncover and control systematic uncertainties, we investigate three potential sources: 1-…