SIMBAD references

2003MNRAS.346..746C - Mon. Not. R. Astron. Soc., 346, 746-772 (2003/December-2)

The Cosmic Lens All-Sky Survey: statistical strong lensing, cosmological parameters, and global properties of galaxy populations.


Abstract (from CDS):

Extensive analyses of statistical strong gravitational lensing are performed based on the final Cosmic Lens All-Sky Survey (CLASS) well-defined statistical sample of flat-spectrum radio sources and current estimates of galaxy luminosity functions per morphological type. The analyses are carried out under the assumption that galactic lenses are well-approximated by singular isothermal ellipsoids and early-type galaxies evolved passively since redshift z ∼ 1. Two goals of the analyses are: (i) to constrain cosmological parameters independently of other techniques (e.g. Type Ia supernovae magnitude-redshift relation, cosmic microwave background anisotropies, galaxy matter power spectra); and (ii) to constrain the characteristic line-of-sight velocity dispersion and the mean projected mass ellipticity for the early-type galaxy population. Depending on how the late-type galaxy population is treated (i.e. whether its characteristic velocity dispersion is constrained or not), we find for a flat universe with a classical cosmological constant that the matter fraction of the present critical density Ωm0.31+0.27–0.14(68 per cent) for the unconstrained case or 0.40+0.28–0.16(68 per cent) for the constrained case, with an additional systematic uncertainty of ~0.11 arising from the present uncertainty in the distribution of CLASS sources in redshift and flux density. For a flat universe with a constant equation of state for dark energy w px(pressure)/ρx(energy density) and the prior constraint w ≥-1, we find that -1 ≤w < -0.55+0.18–0.11(68 per cent) for the unconstrained case or -1 ≤w < -0.41+0.28–0.16(68 per cent) for the constrained case, where w -1 corresponds to a classical cosmological constant. The determined value of the early-type characteristic velocity dispersion [σ(e)*] depends on the faint-end slope of the early-type luminosity function [α(e) ] and the intrinsic shape distribution of galaxies; for equal frequencies of oblates and prolates, we find that σ(e)*(0.3 ≲z ≲ 1) 198+22–18km/s (68 per cent) for a `steep'α(e) -1 or σ(e)*(0.3 ≲z ≲ 1) 181+18 –15km/s (68 per cent) for a `shallow'α(e) -0.54. Finally, from the relative frequencies of doubly imaged sources and quadruply imaged sources, we find that a mean projected mass ellipticity of early-type galaxies {bar}ε{mass} = 0.42 with a 68 per cent lower limit of 0.28 assuming equal frequencies of oblates and prolates.

Abstract Copyright: 2003 RAS

Journal keyword(s): gravitational lensing - methods: statistical - galaxies: haloes - galaxies: kinematics and dynamics - galaxies: structure - cosmological parameters

Simbad objects: 17

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