High-resolution CCD imaging and derived gravitational lens models of 2237+0305

Schneider, D. P.; Turner, Edwin L.; Gunn, James E.; Hewitt, J. N.; Schmidt, Maarten; Lawrence, C. R.

doi:10.1086/114758

Cited by 85 publications

(74 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is clear that whereas components A and C show a small but significant variability (see Shalyapin et al 2002 andGoicoechea et al 2003, for the interpretation of the variation in the component A as the peak of a high-magnification event), images B and D remain relative flat, showing no signs of strong microlensing during the monitoring period. As the expected time delays between the images are short (≤1 day, see Schneider et al 1988;Wambsganss & Paczyński 1994), intrinsic fluctuations would show up in all 4 images almost simultaneously. Keeping in mind the idea expressed in the previous subsection, we used the relative flatness of all four components of Q2237+0305 to statistically infer upper limits on the length of linear tracks in the corresponding magnification patterns.…”

Section: Monitoring Observations Of Q2237+0305mentioning

confidence: 99%

“…Several approaches have been employed in modeling the observed image configuration in Q2237+0305 (Schneider et al 1988;Wambsganss & Paczyński 1994;Chae et al 1998;). These models provide the parameters relevant to microlensing studies: the surface mass density, Σ, and the shear, γ, at the positions of the different images.…”

Section: Lens Models Of Q2237+0305mentioning

confidence: 99%

“…The resulting normalized surface mass density (also called convergence or optical depth) is expressed as κ = Σ/Σ crit . We use here two different sets of values for κ and γ for the four components (Table 1), corresponding to the Schneider et al (1988 and lens models, respectively. We will demonstrate using these two sets that slightly different values for the two local lensing parameters do not change the results, and hence that some scatter in κ and γ of the images does not affect the conclusions.…”

Section: Lens Models Of Q2237+0305mentioning

confidence: 99%

“…The whole procedure was repeated for magnification patterns constructed with the κ and γ values of the Schneider et al (1988) model, see Table 1. The results (presented in the next section) were indistinguishable.…”

Section: Microlensing Simulationsmentioning

confidence: 99%

See 3 more Smart Citations

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

Gil-Merino

Wambsganß

Goicoechea

et al. 2005

A&A

View full text Add to dashboard Cite

Abstract. We present a method for the determination of upper limits on the transverse velocity of the lensing galaxy in the quadruple quasar system Q2237+0305, based on the lack of strong microlensing signatures in the quasar lightcurves. The limits we derive here are based on four months of high quality monitoring data, by comparing the low amplitudes of the lightcurves of the four components with extensive numerical simulations. We make use of the absence of strong variability of the components (especially components B and D) to infer that a "flat" time interval of such a length is only compatible with an effective transverse velocity of the lensing galaxy of v bulk ≤ 630 km s −1 for typical microlenses masses of M µlens = 0.1 M (or v bulk ≤ 2160 km s −1 for M µlens = 1.0 M ) at the 90% confidence level. This method may be applicable in the future to other systems.

show abstract

Section: Monitoring Observations Of Q2237+0305mentioning

confidence: 99%

Section: Lens Models Of Q2237+0305mentioning

confidence: 99%

Section: Lens Models Of Q2237+0305mentioning

confidence: 99%

Section: Microlensing Simulationsmentioning

confidence: 99%

See 2 more Smart Citations

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

Gil-Merino

Wambsganß

Goicoechea

et al. 2005

A&A

View full text Add to dashboard Cite

show abstract

“…Schneider et al (1988) treated the lensing galaxy projected mass distribution as proportional to the observed light distribution and found that "a constant mass-to-light ratio, elliptical, de Vaucoulers bulge reproduces the observed configuration remarkably well." The model was improved in 1992 with the use of a more accurate galaxy light distribution using the Hubble Space telescope data (Rix et al 1992).…”

Section: Time Delay Predictions For Q2237 From Macro-imaging Modelsmentioning

confidence: 99%

Observational determination of the time delays in gravitational lens system Q2237+0305

Vakulik¹,

Schild

Dudinov³

et al. 2006

A&A

View full text Add to dashboard Cite

We present new brightness monitoring observations of the 4 components of gravitationally lensed system Q2237+0305, which show detection of an intrinsic quasar brightness fluctuation at a time of subdued microlensing activity, between June 27 and October 12, 2003. These data were used to determine the time delays between the arrivals of the four images. The measured delays are τ BA ≈ −6, τ CA ≈ 35, and τ DA ≈ 2 h, so they confirm that the long history of brightness monitoring has produced significant detection of microlensing. However the error bars associated with the delays, of order 2 days, are too large to discriminate between competing macro-imaging models. Moreover, our simulations show that for the amplitude of this intrinsic fluctuation and for photometric errors intrinsic to optical monitoring from our 1.5-m telescope or from the OGLE monitoring, a daily sampled brightness record cannot produce reliable lags for model discrimination. We use our simulations to devise a strategy for future delay determination with optical data. Nevertheless, we regard these first estimates to be significant, since they are the first direct measurements of time delays made for this system from ground-based observations in the visual wavelengths. The detected highly correlated fluctuations of the four quasar images provide an extra confirmation of the gravitational-lens nature of Q2237+0305, and give observational justification to the extensive literature which attributes the quasar's previously observed brightness fluctuations to microlensing.

show abstract

Global variational methods in general relativity with applications to gravitational lensing

Giannoni

1999

Annalen der Physik

View full text Add to dashboard Cite

In this note we give an idea of two of the more important theories concerning global variational methods, namely Ljusternik‐Schnirelmann Theory and Morse Theory. Thanks to them it is possible, in many different situations, to link the topological properties of a given manifold X with the number of critical points of the funcionals defined on X. We show, as example, how to apply Morse Theory to obtain a mathematical description of the gravitational lens effect.

show abstract

High-resolution CCD imaging and derived gravitational lens models of 2237+0305

Cited by 85 publications

References 0 publications

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

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

Observational determination of the time delays in gravitational lens system Q2237+0305

Global variational methods in general relativity with applications to gravitational lensing

Contact Info

Product

Resources

About