2016/04/19 by Shuo Cao, Marek Biesiada, Meng Yao +2 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Cosmology #Cosmology and Gravitation Theories #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gravitation #Gravitational lens #Luminosity #Physics #Power law #Redshift #Statistics #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stw932
published as MNRAS, 461, 2192 (2016) · 9 pages, 7 figures, accepted for publication in MNRAS
arxiv created 2016/04/19 · openalex publication_date 2016/06/20 · arxiv updated 2018/01/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We use 118 strong gravitational lenses observed by the SLACS, BOSS emission-line lens survey (BELLS), LSD and SL2S surveys to constrain the total mass profile and the profile of luminosity density of stars (light tracers) in elliptical galaxies up to redshift z ∼ 1. Assuming power-law density profiles for the total mass density, ρ = ρ0(r/r0)−α, and luminosity density, ν = ν0(r/r0)−δ, we investigate the power-law index and its first derivative with respect to the redshift. Using Monte Carlo simulations of the posterior likelihood taking the Planck's best-fitting cosmology as a prior, we find γ = 2.132 ± 0.055 with a mild trend ∂γ/∂zl = −0.067 ± 0.119 when α = δ = γ, suggesting that the total density profile of massive galaxies could have become slightly steeper over cosmic time. Furthermore, similar analyses performed on sub-samples defined by different lens redshifts and velocity dispersions indicate the need of treating low-, intermediate- and high-mass galaxies separately. Allowing δ to be a free parameter, we obtain α = 2.070 ± 0.031, ∂α/∂zl = −0.121 ± 0.078 and δ = 2.710 ± 0.143. The model in which mass traces light is rejected at >95 per cent confidence, and our analysis robustly indicates the presence of dark matter in the form of a mass component that is differently spatially extended than the light. In this case, intermediate-mass elliptical galaxies (200 km s−1 <σap ≤ 300 km s−1) show the best consistency with the singular isothermal sphere as an effective model of galactic lenses.