The statistics of gravitational lenses - The distributions of image angular separations and lens redshifts

Turner, Edwin L.; Ostriker, Jeremiah P.; Gott, J. Richard

doi:10.1086/162379

Cited by 623 publications

(646 citation statements)

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“…Although late-type galaxies are more abundant than early types, they tend to have lower masses and hence contribute no more than 10%-20% of the lensing optical depth. This is a standard prediction of lens statistics models (Turner et al 1984;Fukugita & Turner 1991;Maoz & Rix 1993) that has been borne out by the data (e.g., Fassnacht & Cohen 1998;Keeton et al 1998;Kochanek et al 2000;Lubin et al 2000). We could attempt to model both the early-and late-type deflector populations in order to compute the total lensing optical depth and compare it with the observed number of lenses produced by earlyand late-type galaxies (as done by Chae et al 2002;Chae 2003).…”

Section: The Deflector Populationmentioning

confidence: 92%

Improved Cosmological Constraints from Gravitational Lens Statistics

Mitchell¹,

Keeton²,

Frieman³

et al. 2005

ApJ

130

238

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We combine the Cosmic Lens All-Sky Survey (CLASS) with new Sloan Digital Sky Survey (SDSS) data on the local velocity dispersion distribution function of E /S0 galaxies, ( ), to derive lens statistics constraints on Ã and m . Previous studies of this kind relied on a combination of the E /S0 galaxy luminosity function and the FaberJackson relation to characterize the lens galaxy population. However, ignoring dispersion in the Faber-Jackson relation leads to a biased estimate of ( ) and therefore biased and overconfident constraints on the cosmological parameters. The measured velocity dispersion function from a large sample of E/S0 galaxies provides a more reliable method for probing cosmology with strong lens statistics. Our new constraints are in good agreement with recent results from the redshift-magnitude relation of Type Ia supernovae. Adopting the traditional assumption that the E/S0 velocity function is constant in comoving units, we find a maximum likelihood estimate of Ã ¼ 0:74 0:78 for a spatially flat universe (where the range reflects uncertainty in the number of E/S0 lenses in the CLASS sample) and a 95% confidence upper bound of Ã < 0:86. If ( ) instead evolves in accord with the extended PressSchechter theory, then the maximum likelihood estimate for Ã becomes 0.72-0.78, with the 95% confidence upper bound Ã < 0:89. Even without assuming flatness, lensing provides independent confirmation of the evidence from Type Ia supernovae for a nonzero dark energy component in the universe.

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Section: The Deflector Populationmentioning

confidence: 92%

Improved Cosmological Constraints from Gravitational Lens Statistics

Mitchell¹,

Keeton²,

Frieman³

et al. 2005

ApJ

130

238

View full text Add to dashboard Cite

show abstract

“…Early studies of lens statistics used lens models with circular symmetry, such as singular isothermal spheres, for which the magnification bias is easy to calculate (e.g., Turner, Ostriker, & Gott 1984). However, symmetric models only produce two-image lenses and cannot be used to interpret the statistics of each morphology separately.…”

Section: Introductionmentioning

confidence: 99%

Analytic Expressions for Mean Magnification by a Quadrupole Gravitational Lens

Finch

Carlivati²,

Winn

et al. 2002

ApJ

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We derive an analytic expression for the mean magnification due to strong gravitational lensing, using a simple lens model: a singular isothermal sphere embedded in an external shear field. We compute separate expressions for two-image and four-image lensing. For four-image lensing, the mean magnification takes a particularly simple form:, where is the external shear. We compare our analytic results with a numerical evaluation of the full magnification distribution. The results can be used to understand the magnification bias that favors the discovery of four-image systems over two-image systems in fluxlimited lens surveys.

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“…For the former, one can have lensing by a star (M B 1 in a M _ ) galaxy with deÑection angles of the order of milliarcseconds and by a galaxy (M B 1011 with deÑection angles of M _ ) the order of arcseconds. For the latter, model-dependent luminosity distances must be applied, but this gives us the opportunity to determine cosmological parameters such as the Hubble constant, the deceleration parameter, H 0 , q 0 , and the cosmological constant, " (Turner, Ostriker, & Gott 1984 ;Gott & Park 1989 ;Turner 1990 ;Fukugita, Futamase, & Kasai 1990). A "" giant ÏÏ (cosmological) gravitational lens of the order of 157A has also been detected, but the immense deÑection angle is hardly believed to be the e †ect of lensing (Blanford, Phinney, & Narayan 1987).…”

Section: Introductionmentioning

confidence: 99%

Boson Stars as Gravitational Lenses

Dąbrowski

Schunck

2000

ApJ

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We discuss boson stars as possible gravitational lenses and study the lensing e †ect of these objects made up of scalar particles. The mass and the size of a boson star may vary from an individual Newtonian object similar to the Sun to the general relativistic size and mass of a galaxy close to its Schwarzschild radius. We assume boson stars to be transparent, which allows the light to pass through them, although the light is gravitationally deÑected. We assume boson stars of mass M \ 1010 to be on M _ noncosmological distance from the observer. We discuss the lens equation for these stars as well as the details of magniÐcation. We Ðnd that there are typically three images of a star, but the deÑection angles may vary from arcseconds to even degrees. There is one tangential critical curve (Einstein ring) and one radial critical curve for tangential and radial magniÐcation, respectively. Moreover, the deÑection angles for the light passing through the gravitational Ðeld of boson stars can be very large (even of the order of degrees), which reÑects the fact that they are very strong relativistic objects. We derive a suitable formula for the lens equation for such large deÑection angles. Although the large deÑection angle images are highly demagniÐed, their existence in the area of the tangential critical curve may help with observational detection of suitable lenses possessing characteristic features of boson stars, which could also serve as a direct evidence for scalar Ðelds in the universe.

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The statistics of gravitational lenses - The distributions of image angular separations and lens redshifts

Cited by 623 publications

References 0 publications

Improved Cosmological Constraints from Gravitational Lens Statistics

Improved Cosmological Constraints from Gravitational Lens Statistics

Analytic Expressions for Mean Magnification by a Quadrupole Gravitational Lens

Boson Stars as Gravitational Lenses

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