Constraints on cosmological models from strong gravitational lensing systems

Abstract

Strong lensing has developed into an importantastrophysical tool for probing both cosmology and galaxies (theirstructure, formation, and evolution). Using the gravitationallensing theory and cluster mass distribution model, we try tocollect a relatively complete observational data concerning theHubble constant independent ratio between two angular diameterdistances Dds/Ds from various large systematic gravitationallens surveys and lensing by galaxy clusters combined with X-rayobservations, and check the possibility to use it in the future ascomplementary to other cosmological probes. On one hand, stronglygravitationally lensed quasar-galaxy systems create such a newopportunity by combining stellar kinematics (central velocitydispersion measurements) with lensing geometry (Einstein radiusdetermination from position of images). We apply such a method to acombined gravitational lens data set including 70 data points fromSloan Lens ACS (SLACS) and Lens Structure and Dynamics survey(LSD). On the other hand, a new sample of 10 lensing galaxy clusterswith redshifts ranging from 0.1 to 0.6 carefully selected fromstrong gravitational lensing systems with both X-ray satelliteobservations and optical giant luminous arcs, is also used toconstrain three dark energy models (ΛCDM, constant w andCPL) under a flat universe assumption. For the full sample (n = 80)and the restricted sample (n = 46) including 36 two-image lenses and10 strong lensing arcs, we obtain relatively good fitting values ofbasic cosmological parameters, which generally agree with theresults already known in the literature. This results encouragesfurther development of this method and its use on larger samplesobtained in the future.