English
Related papers

Related papers: Time delays in PG1115+080: new estimates

200 papers

We have observed the gravitational lens system Q2237+0305 from the Maidanak Observatory over the period from August 2002 to November 2003. Here we report the results of our observations. We implemented a two-stage technique that has been…

Strong lens time delays have been widely used in cosmological studies, especially to infer $H_0$. The upcoming LSST will provide several hundred well measured time delays from the light curves of lensed quasars. However, due to the…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-29 Kai Liao

In this work, we present a homogeneous curve-shifting analysis using the difference-smoothing technique of the publicly available light curves of 24 gravitationally lensed quasars, for which time delays have been reported in the literature.…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-24 S. Rathna Kumar , C. S. Stalin , T. P. Prabhu

The measurement of the Shapiro time delay in binary pulsar systems with highly inclined orbit can be affected both by the motion of the pulsar's companion because of the finite time it takes a photon to cross the binary, and by the…

Astrophysics · Physics 2009-11-13 Roman R. Rafikov , Dong Lai

We present the results of a recent reverberation-mapping campaign undertaken to improve measurements of the radius of the broad line region and the central black hole mass of the quasar PG 2130+099. Cross correlation of the 5100 angstrom…

The importance of alternative methods for measuring the Hubble constant, such as time-delay cosmography, is highlighted by the recent Hubble tension. It is paramount to thoroughly investigate and rule out systematic biases in all…

The gravitational potential responsible for the lensing effect in SBS 1520+530 is studied over length scales from a few arc-seconds to a few arc-minutes. For this purpose, we use sharply deconvolved Hubble Space Telescope images in the…

Astrophysics · Physics 2009-11-07 C. Faure , F. Courbin , J. P. Kneib , D. Alloin , M. Bolzonella , I. Burud

Lensed quasars and supernovae can be used to study galaxies' gravitational potential and measure cosmological parameters. The typical image separation of objects lensed by galaxies is of the order of 0.5". Therefore, finding the ones with…

Instrumentation and Methods for Astrophysics · Physics 2021-09-01 Ofer M. Springer , Eran O. Ofek

In late 2014, four images of Supernova (SN) "Refsdal," the first known example of a strongly lensed SN with multiple resolved images, were detected in the MACS J1149 galaxy-cluster field. Following the images' discovery, the SN was…

One of the main objectives of the Cosmic Lens All-Sky Survey (CLASS) collaboration has been to find gravitational lens (GL) systems at radio wavelengths that are suitable for the determination of time delays between image pairs. The survey…

Astrophysics · Physics 2009-11-06 L. V. E. Koopmans , the CLASS collaboration

On 22nd September 2017, the IceCube Collaboration detected a neutrino with energy of about 290 TeV from the direction of the gamma-ray blazar TXS 0506+056, located at a distance of about 1.75 Gpc. During the same time, enhanced gamma-ray…

High Energy Astrophysical Phenomena · Physics 2019-03-05 Sibel Boran , Shantanu Desai , Emre O. Kahya

We present an analysis of two seasons of archival, multi-frequency VLA monitoring of the quad lens system JVAS B1422+231, the 15-GHz data of which have previously been published. The 8.4- and 15-GHz variability curves show significant…

Astrophysics of Galaxies · Physics 2023-03-29 A. D. Biggs

We present a fully Bayesian framework for time delay inference and stationarity tests in quasar light curves using marginalised Gaussian processes. The model separates a deterministic, non-stationary drift (piecewise linear mean) from…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-20 Namu Kroupa , David Yallup , Will Handley

We present a simultaneous analysis of 10 galaxy lenses having time-delay measurements. For each lens we derive a detailed free-form mass map, with uncertainties, and with the additional requirement of a shared value of the Hubble parameter…

Astrophysics · Physics 2009-11-11 P. Saha , J. Coles , A. V. Maccio' , L. L. R. Williams

This paper examines free-form modeling of gravitational lenses using Bayesian ensembles of pixelated mass maps. The priors and algorithms from previous work are clarified and significant technical improvements are made. Lens reconstruction…

Astrophysics · Physics 2009-11-13 Jonathan Coles

PSR J1012$-$4235 is a 3.1ms pulsar in a wide binary (37.9 days) with a white dwarf companion. We detect, for the first time, a strong relativistic Shapiro delay signature in PSR J1012$-$4235. Our detection is the result of a timing analysis…

High Energy Astrophysical Phenomena · Physics 2023-11-23 T. Gautam , P. C. C. Freire , J. Wu , V. Venkatraman Krishnan , M. Kramer , E. D. Barr , M. Bailes , A. D. Cameron

Future large ensembles of time delay lenses have the potential to provide interesting cosmological constraints complementary to those of other methods. In a flat universe with constant w including a Planck prior, LSST time delay…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Dan Coe , Leonidas Moustakas

We present an analysis of archival multi-frequency Very Large Array monitoring data of the two-image gravitational lens system CLASS B1600+434, including the polarization properties at 8.5 GHz. From simulating radio light curves…

Astrophysics of Galaxies · Physics 2021-07-07 A. D. Biggs

We present results from 3.6 cm observations of the quasar pair 1038+528 A and B, made in 1995 using the VLBA together with the Effelsberg 100m telescope. We describe the use of a phase-referencing technique to measure the astrometric…

Astrophysics · Physics 2007-05-23 Maria J. Rioja , Richard W. Porcas

We present the results of a radio variability study of the gravitational lens PMN J1838-3427. Our motivation was to determine the Hubble constant by measuring the time delay between variations of the two quasar images. We monitored the…