On the universality of microlensing in quadruple gravitational lenses

Witt, Hans J.; Mao, Shude; Schechter, Paul L.

doi:10.1086/175499

Cited by 158 publications

(201 citation statements)

References 26 publications

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“…These findings support the view of Witt et al (1995) about the general nature of quadrupole systems and the inevitability of micro-lensing events in them. Further evidence of the continuous influence of micro-lensing is the time variability of the magnitude difference between the lensed components, which vary over a very large range (Section 7).…”

Section: Micro-lensing Eventssupporting

confidence: 87%

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Adaptive PSF fitting – a highly performing photometric method and light curves of the GLS H1413+117: time delays and micro-lensing effects

Akhunov

Wertz

Elyiv

et al. 2016

Mon. Not. R. Astron. Soc.

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We present new photometric observations of H1413+117 acquired during seasons between 2001 and 2008 in order to estimate the time delays between the lensed quasar images and to characterize at best the on-going micro-lensing events. We propose a highly performing photometric method called the adaptive point spread function fitting and have successfully tested this method on a large number of simulated frames. This has enabled us to estimate the photometric error bars affecting our observational results. We analysed the V-and R-band light curves and V-R colour variations of the A-D components which show short-and long-term brightness variations correlated with colour variations. Using the χ 2 and dispersion methods, we estimated the time delays on the basis of the R-band light curves over the seasons between 2003 and 2006. We have derived the new values: t AB = −17.4 ± 2.1, t AC = −18.9 ± 2.8 and t AD = 28.8 ± 0.7 d using the χ 2 method (B and C are leading, D is trailing) with 1σ confidence intervals. We also used available observational constraints (resp. the lensed image positions, the flux ratios in mid-IR and two sets of time delays derived in the present work) to update the lens redshift estimation. We obtained z l = 1.95 +0.06 −0.10 which is in good agreement with previous estimations. We propose to characterize two kinds of micro-lensing events: micro-lensing for the A,

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Section: Micro-lensing Eventssupporting

confidence: 87%

“…Moreover, the micro-lensing of the D component shows a chromatic dependence (Hutsemékers et al 2010). This result is directly consistent with the estimation of the duration of the micro-lensing events in H1413+117 by Witt, Mao & Schechter (1995).…”

Section: Introductionsupporting

confidence: 91%

Adaptive PSF fitting – a highly performing photometric method and light curves of the GLS H1413+117: time delays and micro-lensing effects

Akhunov

Wertz

Elyiv

et al. 2016

Mon. Not. R. Astron. Soc.

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“…This may be due to inaccuracies in the modeling, an underestimation of the error bars, or microlensing Ñuctua-tions at the 10% level, which is to be expected for a source 15 times the size of an Einstein radius (assuming p \ 0.5 ; Refsdal & Stabell 1991). All other published gravitational lens models for Einstein Cross have larger s2 (Kent & Falco 1988 ;Kochanek 1991 ;Rix, Schneider, & Bahcall 1992 ;Wambsganss & 1994 ;Witt et al 1995 ;Chae, Paczynski Turnshek, & Khersonsky 1998).…”

Section: Microlensing Constraintsmentioning

confidence: 95%

“…Table 3 shows the predictions of the j \ 1 model from Schmidt, Webster, & Lewis (1998, hereafter SWL98), which were derived without using the Ñux ratios as a model constraint. For all published models s2 \ was computed, where Kochanek (1991) with s2 \ 7, and model 1 of Witt, Mao, & Schechter (1995) with s2 \ 8. These s2 indicate that there may be deviations of the IR magniÐ-cations from the predicted magniÐcations at the level of 10%.…”

Section: Microlensing Constraintsmentioning

confidence: 99%

Keck Mid‐Infrared Imaging of QSO 2237+0305

Agol

Jones

Blaes

2000

ApJ

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Using the Long Wavelength Spectrometer on Keck, we have imaged the gravitationally lensed radioquiet quasi-stellar object QSO 2237]0305 at 8.9 and 11.7 km for the Ðrst time. The mid-IR Ñux ratios are inconsistent with the optical Ñux ratios but agree with the radio Ñux ratios and with some published gravitational lens models. These Ñux ratios indicate that the IR emission is not a †ected by microlensing, which rules out the synchrotron emission model. The IR emission is likely produced by hot dust extended on a length scale of more than 0.03 pc. The spectral energy distribution further implies a narrow range of dust temperatures, suggesting that the dust may be located in a shell extending between D1 and 3 pc from the nucleus and intercepting about half of the QSO luminosity.

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“…where b \ 1 corresponds to the singular isothermal sphere and b \ 0 describes a point mass (Witt, Mao, & Schechter 1995). The deÑection angle for the SSS model is…”

Section: Gravitational Lens Mass Modelsmentioning

confidence: 99%

Investigation of Gravitational Lens Mass Models

Knudson

Griffiths

2001

The Astronomical Journal

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We have previously reported the discovery of strong gravitational lensing by faint elliptical galaxies using the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space T elescope, and here we investigate their potential usefulness in placing constraints on lens mass models. We compare various ellipsoidal surface mass distributions, including those with and without a core radius, as well as models in which the mass distributions are assumed to have the same axis ratio and orientation as the galaxy light.We also study models that use a spherical mass distribution having various proÐles, both empirical and following those predicted by cold dark matter simulations. These models also include a gravitational shear term. The model parameters and associated errors have been derived by two-dimensional analysis of the observed WFPC2 images. The maximum likelihood procedure iteratively converges simultaneously on the model for the lensing elliptical galaxy and the lensed image components. The motivation for this study was to distinguish between these mass models with this technique. However, we Ðnd that, despite using the full image data rather than just locations and integrated magnitudes, the lenses are Ðtted equally well with several of the mass models. Each of the mass models generates a similar conÐgu-ration but with a di †erent magniÐcation and cross-sectional area within the caustic, and both of these latter quantities govern the discovery probability of lensing in the survey. These di †erences contribute to considerable cosmic scatter in any estimate of the cosmological constant, ", using gravitational lenses.

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On the universality of microlensing in quadruple gravitational lenses

Cited by 158 publications

References 26 publications

Adaptive PSF fitting – a highly performing photometric method and light curves of the GLS H1413+117: time delays and micro-lensing effects

Adaptive PSF fitting – a highly performing photometric method and light curves of the GLS H1413+117: time delays and micro-lensing effects

Keck Mid‐Infrared Imaging of QSO 2237+0305

Investigation of Gravitational Lens Mass Models

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