Limits on the transverse velocity of the 
 lensing galaxy   in Q2237+0305 from the lack of strong 
 microlensing variability

Gil-Merino, R.; Wambsganß, J.; Goicoechea, L. J.; Lewis, Geraint F.

doi:10.1051/0004-6361:20047123

Cited by 22 publications

(32 citation statements)

References 32 publications

(41 reference statements)

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“…The same effect, but not as strong, is seen in the C-A image, again suggesting a slight demagnification of C, a magnification of A or a combination of the two. In previous microlensing studies, component D has not been seen to have as strong a microlensing signal as A and C have ( Irwin et al 1989;Alcalde et al 2002;Gil-Merino et al 2005) so therefore it is perhaps more likely that we are seeing the magnification of image A.…”

Section: Q2237+030mentioning

confidence: 84%

Extinction Curves of Lensing Galaxies out toz= 1

Elíasdóttir

Hjorth

Toft

et al. 2006

ASTROPHYS J SUPPL S

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We present a survey of the extinction properties of 10 lensing galaxies, in the redshift range z ¼ 0:04Y1:01, using multiply lensed quasars imaged with the ESO VLT in the optical and near-infrared. The multiple images act as ''standard light sources'' shining through different parts of the lensing galaxy, allowing for extinction studies by comparison of pairs of images. We explore the effects of systematics in the extinction curve analysis, including extinction along both lines of sight and microlensing, using theoretical analysis and simulations. In the sample, we see variation in both the amount and type of extinction. Of the 10 systems, seven are consistent with extinction along at least one line of sight. The mean differential extinction for the most extinguished image pair for each lens isĀ(V ) ¼ 0:56 AE 0:04, using Galactic extinction law parameterization. The corresponding meanR V ¼ 2:8 AE 0:4 is consistent with that of the Milky Way at R V ¼ 3:1, where R V ¼ A(V )/E(B À V ). We do not see any strong evidence for evolution of extinction properties with redshift. Of the 10 systems, B1152+199 shows the strongest extinction signal of A(V ) ¼ 2:43 AE 0:09 and is consistent with a Galactic extinction law with R V ¼ 2:1 AE 0:1. Given the similar redshift distribution of SN Ia hosts and lensing galaxies, a large space-based study of multiply imaged quasars would be a useful complement to future dark energy SN Ia surveys, providing independent constraints on the statistical extinction properties of galaxies up to z $ 1. Subject headingg s: dust, extinction -galaxies: ISM -gravitational lensing 1 Based on observations made with ESO Telescopes at the La Silla or Paranal Observatories under program IDs 065.O-0666 and 066.A-0264.

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Section: Q2237+030mentioning

confidence: 84%

Extinction Curves of Lensing Galaxies out toz= 1

Elíasdóttir

Hjorth

Toft

et al. 2006

ASTROPHYS J SUPPL S

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“…Assuming that the peculiar velocities of the source and lens, in their own planes, are of the same order, the last term can be neglected as well. With these approximations, the effective source velocity is reduced to the expression In the case of lensed system Q2237+0305, several studies found the transverse velocity of the lens to be in the range between approximately 500 and 2000 km s −1 (Wyithe, Webster & Turner ; Kochanek ; Gil‐Merino et al ). We adopted three values in this range and calculated the corresponding effective source velocity and rise times of HMEs.…”

Section: Resultsmentioning

confidence: 99%

Gravitational microlensing of active galactic nuclei dusty tori

Jovanović

Baes

2012

Monthly Notices of the Royal Astronomical Society

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We investigated the gravitational microlensing of active galactic nuclei dusty tori in the case of lensed quasars in the infrared domain. The dusty torus is modelled as a clumpy two-phase medium. To obtain spectral energy distributions and images of tori at different wavelengths, we used the 3D Monte Carlo radiative transfer code SKIRT. A ray-shooting technique has been used to calculate microlensing magnification maps. We simulated microlensing by the stars in the lens galaxy for different configurations of the lensed system and different values of the torus parameters, in order to estimate (a) amplitudes and time-scales of high magnification events and (b) the influence of geometrical and physical properties of dusty tori on light curves in the infrared domain. We found that, despite their large size, dusty tori could be significantly affected by microlensing in some cases, especially in the near-infrared domain (rest frame). The very long time-scales of such events, in the range from several decades to hundreds of years, are limiting the practical use of this method to study the properties of dusty tori. However, our results indicate that, when studying flux ratios between the images in different wavebands of lensed quasars, one should not disregard the possibility that the nearand mid-infrared flux ratios could be under the influence of microlensing.

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“…The microlensing activity during our observations was not as important as during the periods studied by Kochanek (2004) and Anguita et al (2008). Furthermore, Anguita et al (2008) considered a shorter observation period, and used the velocity prior of Gil-Merino et al (2005), which is more constraining towards high velocities (hence favoring smaller source sizes) than the one we considered in the present study. This explains, why our derivedR s is slightly larger.…”

Section: +019mentioning

confidence: 99%

“…Previous studies have considered various priors (e.g. Kochanek 2004;Gil-Merino et al 2005). Some are more restrictive than others, but most of them have in common that they favor transverse velocities of ∼600 km s −1 in the lens plane, which correspond to projected transverse velocities of ∼6000 km s −1 in the source plane of QSO 2237+0305 (Kayser et al 1986).…”

Section: Bayesian Analysismentioning

confidence: 99%

Microlensing variability in the gravitationally lensed quasar QSO 2237+0305 $\mathsf{\equiv}$ the Einstein Cross

Eigenbrod¹,

Courbin²,

Meylan³

et al. 2008

A&A

Self Cite

115

132

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We present the continuation of our long-term spectroscopic monitoring of the gravitationally lensed quasar QSO 2237+0305. We investigate the chromatic variations observed in the UV/optical continuum of both quasar images A and B, and compare them with numerical simulations to infer the energy profile of the quasar accretion disk. Our procedure combines the microlensing ray-shooting technique with Bayesian analysis, and derives probability distributions for the source sizes as a function of wavelength. We find that the effective caustic crossing timescale is 4.0 ± 1.0 months. Using a robust prior on the effective transverse velocity, we find that the source responsible for the UV/optical continuum has an energy profile well reproduced by a power-law R ∝ λ ζ with ζ = 1.2 ± 0.3, where R is the source size responsible for the emission at wavelength λ. This is the first accurate, model-independent determination of the energy profile of a quasar accretion disk on such small scales.

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Limits on the transverse velocity of the lensing galaxy in Q2237+0305 from the lack of strong microlensing variability

Cited by 22 publications

References 32 publications

Extinction Curves of Lensing Galaxies out toz= 1

Extinction Curves of Lensing Galaxies out toz= 1

Gravitational microlensing of active galactic nuclei dusty tori

Microlensing variability in the gravitationally lensed quasar QSO 2237+0305 $\mathsf{\equiv}$ the Einstein Cross

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