Testing dark energy models with a new sample of strong-lensing systems
Abstract
Inspired by a new compilation of strong-lensing systems, which consist of 204 points in the redshift range 0.0625 < zl < 0.958 for the lens and 0.196 < zs < 3.595 for the source, we constrain three models that generate a late cosmic acceleration: the Ï-cold dark matter model, the ChevallierâPolarskiâLinder, and the JassalâBaglaâPadmanabhan parametrizations. Our compilation contains only those systems with early-type galaxies acting as lenses, with spectroscopically measured stellar velocity dispersions, estimated Einstein radius, and both the lens and source redshifts. We assume an axially symmetric mass distribution in the lens equation, using a correction to alleviate differences between the measured velocity dispersion (Ï) and the dark matter halo velocity dispersion (ÏDM) as well as other systematic errors that may affect the measurements. We have considered different subsamples to constrain the cosmological parameters of each model. Additionally, we generate a mock data of SLS to asses the impact of the chosen mass profile on the accuracy of Einstein radius estimation. Our results show that cosmological constraints are very sensitive to the selected data: Some cases show convergence problems in the estimation of cosmological parameters (e.g. systems with observed distance ratio Dobs < 0.5), others show high values for the Ï2 function (e.g. systems with a lens equation Dobs > 1 or high velocity dispersion Ï > 276 km sâ1). However, we obtained a fiduciary sample with 143 systems, which improves the constraints on each tested cosmological model.
Más información
| Título según WOS: | Testing dark energy models with a new sample of strong-lensing systems |
| Título según SCOPUS: | Testing dark energy models with a new sample of strong-lensing systems |
| Título de la Revista: | Monthly Notices of the Royal Astronomical Society |
| Volumen: | 498 |
| Número: | 4 |
| Editorial: | Oxford University Press |
| Fecha de publicación: | 2020 |
| Página final: | 6033 |
| Idioma: | English |
| DOI: |
10.1093/mnras/staa2760 |
| Notas: | ISI, SCOPUS |