Improved Constraints on the Gravitational Lens Q0957+561. Ii. Strong Lensing

Nakajima, Reiko; Bernstein, G. M.; Fadely, Ross; Keeton, Charles R.; Schrabback, T.

doi:10.1088/0004-637x/711/1/246

Cited by 71 publications

(76 citation statements)

References 137 publications

(212 reference statements)

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“…Lovell et al 1998), SDSS J1004+4112 (Fohlmeister et al 2007(Fohlmeister et al , 2008, QSO 0957+561 (e.g. Oscoz et al 2001;Shalyapin et al 2008;Fadely et al 2010). Two other systems are not presented here because we already published improved astrometry and time delays: WFI J2033-4723 (Vuissoz et al 2008) and HE 0435-1223 (Courbin et al 2011).…”

Section: -Class B1600+434 (I)mentioning

confidence: 99%

“…First local and global minima were searched for by running the minimization from an ensemble of at least 1000 randomly distributed initial parameters. Second, we sampled the parameter space in the vicinity of the identified global minimum using an adaptive Metropolis Hastings Monte Carlo Markov Chain (MCMC) algorithm implemented in LENSMODEL (Fadely et al 2010). For each point of the MCMC, we calculated the relative likelihood of a parameter p based on the χ 2 statistics (i.e.…”

Section: Lens Modelingmentioning

confidence: 99%

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COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

Sluse

Chantry

Magain

et al. 2012

A&A

121

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Gravitationally lensed quasars can be used as powerful cosmological and astrophysical probes. We can (i) infer the Hubble constant H 0 based on the so-called time-delay technique, (ii) unveil substructures along the line-of-sight toward distant galaxies, and (iii) compare the shape and the slope of baryons and dark matter distributions in the inner regions of galaxies. To reach these goals, we need highaccuracy astrometry of the quasar images relative to the lensing galaxy and morphology measurements of the lens. In this work, we first present new astrometry for 11 lenses with measured time delays, namely, JVAS B0218+357, SBS 0909+532, RX J0911.4+0551, FBQS J0951+2635, HE 1104-1805, PG 1115+080, JVAS B1422+231, SBS 1520+530, CLASS B1600+434, CLASS B1608+656, and HE 2149-2745. These measurements proceed from the use of the Magain-Courbin-Sohy (MCS) deconvolution algorithm applied in an iterative way (ISMCS) to near-IR HST images. We obtain a typical astrometric accuracy of about 1-2.5 mas and an accurate shape measurement of the lens galaxy. Second, we combined these measurements with those of 14 other lensing systems, mostly from the COSMOGRAIL set of targets, to present new mass models of these lenses. The modeling of these 25 gravitational lenses led to the following results: 1) in four double-image quasars (HE0047-1746, J1226-006, SBS 1520+530, and HE 2149-2745), we show that the influence of the lens environment on the time delay can easily be quantified and modeled, hence putting these lenses with high priority for time-delay determination; 2) for quadruple-image quasars, the difficulty often encountered in reproducing the image positions to milli-arcsec accuracy (astrometric anomaly problem) is overcome by explicitly including the nearest visible galaxy/satellite in the lens model. However, one anomalous system (RXS J1131-1231) does not show any luminous perturber in its vicinity, and three others (WFI 2026-4536, WFI 2033, and B2045+265) have problematic modeling. These four systems are the best candidates for a pertubation by a dark matter substructure along the line-of-sight; 3) we revisit the correlation between the position angle (PA) and ellipticity of the light and of the mass distribution in lensing galaxies. As in previous studies, we find a significant correlation between the PA of the light and of the mass distributions. However, in contrast with these same studies, we find that the ellipticity of the light and of the mass also correlate well, suggesting that the overall spatial distribution of matter is not very different from the baryon distribution in the inner ∼5 kpc of lensing galaxies. This offers a new test for high-resolution hydrodynamical simulations.

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Section: -Class B1600+434 (I)mentioning

confidence: 99%

Section: Lens Modelingmentioning

confidence: 99%

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

Sluse

Chantry

Magain

et al. 2012

A&A

121

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“…To estimate the model uncertainties, we then sample the posterior probability distribution of the parameter space using an adaptive Metropolis Hastings Monte Carlo Markov Chain (MCMC) algorithm. This technique is implemented in LENSMODEL and described in Fadely et al (2010). In practice, an ensemble of 15 different chains are run, each chain consisting of a sequence of trial steps drawn from a multivariate Gaussian distribution of width estimated during the first step of the process.…”

Section: Parametric Modelingmentioning

confidence: 99%

“…In 5% of the steps, the covariance matrix is diagonal, allowing us to use a large step along one of the axis and to escape local minima in the χ 2 surface. We use the same criterion as Fadely et al (2010) to assess that any MCMC run has converged. Finally, for each point of the MCMC, we calculate the relative likelihood of a parameter p based on the χ 2 statistics (i.e.…”

Section: Parametric Modelingmentioning

confidence: 99%

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

Chantry¹,

Sluse²,

Magain³

2010

A&A

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Aims. We attempt to place very accurate positional constraints on seven gravitationally lensed quasars currently being monitored by the COSMOGRAIL collaboration, and shape parameters for the light distribution of the lensing galaxy. We attempt to determine simple mass models that reproduce the observed configuration and predict time delays. We finally test, for the quads, whether there is evidence of astrometric perturbations produced by substructures in the lensing galaxy, which may preclude a good fit with the simple models. Methods. We apply the iterative MCS deconvolution method to near-IR HST archival data of seven gravitationally lensed quasars. This deconvolution method allows us to differentiate the contributions of the point sources from those of extended structures such as Einstein rings. This method leads to an accuracy of 1-2 mas in the relative positions of the sources and lens. The limiting factor of the method is the uncertainty in the instrumental geometric distortions. We then compute mass models of the lensing galaxy using state-of-the-art modeling techniques. Results. We determine the relative positions of the lensed images and lens shape parameters of seven lensed quasars: HE 0047-1756, RX J1131-1231, SDSS J1138+0314, SDSS J1155+6346, SDSS J1226-0006, WFI J2026-4536, and HS 2209+1914. The lensed image positions are derived with 1-2 mas accuracy. Isothermal and de Vaucouleurs mass models are calculated for the whole sample. The effect of the lens environment on the lens mass models is taken into account with a shear term. Doubly imaged quasars are equally well fitted by each of these models. A large amount of shear is necessary to reproduce SDSS J1155+6346 and SDSS J1226-006. In the latter case, we identify a nearby galaxy as the dominant source of shear. The quadruply imaged quasar SDSS J1138+0314 is reproduced well by simple lens models, which is not the case for the two other quads, RX J1131-1231 and WFI J2026-4536. This might be the signature of astrometric perturbations caused by massive substructures in the galaxy, which are unaccounted for by the models. Other possible explanations are also presented.

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“…of quasars lensed by galaxies) have especially good complementarity with SN [25]. While this technique, which requires both imaging and spectroscopy for accurate lens mass modeling, is not a canonical part of any of the surveys we have discussed, individual groups are pursuing time delay surveys [26][27][28].…”

Section: Additional Information a Time Delay Distancesmentioning

confidence: 99%

CMB polarization impact on cosmological constraints

Das

Linder

2012

Phys. Rev. D

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Cosmic microwave background polarization encodes information not only on the early universe but also dark energy, neutrino mass, and gravity in the late universe through CMB lensing. Ground based surveys such as ACTpol, PolarBear, SPTpol significantly complement cosmological constraints from the Planck satellite, strengthening the CMB dark energy figure of merit and neutrino mass constraints by factors of 3-4. This changes the dark energy probe landscape. We evaluate the state of knowledge in 2017 from ongoing experiments including dark energy surveys (supernovae, weak lensing, galaxy clustering), fitting for dynamical dark energy, neutrino mass, and a modified gravitational growth index. Adding a modest strong lensing time delay survey improves those dark energy constraints by a further 32%, and an enhanced low redshift supernova program improves them by 26%.

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Improved Constraints on the Gravitational Lens Q0957+561. Ii. Strong Lensing

Cited by 71 publications

References 137 publications

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

CMB polarization impact on cosmological constraints

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