Implications of the lens redshift distribution of strong lensing systems: cosmological parameters and the global properties of early-type galaxies

Ma, Yu-Bo (Aff1, 0000 0004 1757 5302, Department of Physics, Shanxi Datong University, 037009, Datong, China) ; Cao, Shuo (Aff2, 0000 0004 1789 9964, Department of Astronomy, Beijing Normal University, 100875, Beijing, China) ; Zhang, Jia (Aff3, Department of Physics, School of Mathematics and physics, Weinan Normal University, 714099, Shanxi, China) ; Geng, Shuaibo (Aff2, 0000 0004 1789 9964, Department of Astronomy, Beijing Normal University, 100875, Beijing, China) ; Liu, Yuting (Aff2, 0000 0004 1789 9964, Department of Astronomy, Beijing Normal University, 100875, Beijing, China) ; Liu, Tonghua (Aff2, 0000 0004 1789 9964, Department of Astronomy, Beijing Normal University, 100875, Beijing, China) ; Pan, Yu (Aff4, 0000 0001 0381 4112, College of Science, Chongqing University of Posts and Telecommunications, 400065, Chongqing, China)

07 February 2019

Abstract: In this paper, we assemble a well-defined sample of early-type gravitational lenses extracted from a large collection of 158 systems, and use the redshift distribution of galactic-scale lenses to test the standard cosmological model ( Λ CDM) and the modified gravity theory (DGP). Two additional sub-samples are also included to account for possible selection effect introduced by the detectability of lens galaxies. Our results show that independent measurement of the matter density parameter ( Ωm ) could be expected from such strong lensing statistics. Based on future measurements of strong lensing systems from the forthcoming LSST survey, one can expect Ωm to be estimated at the precision of ΔΩm∼0.006 , which provides a better constraint on Ωm than Planck 2015 results. Moreover, use the lens redshift test is also used to constrain the characteristic velocity dispersion of the lensing galaxies, which is well consistent with that derived from the optical spectroscopic observations. A parameter fE is adopted to quantify the relation between the lensing-based velocity dispersion and the corresponding stellar value. Finally, the accumulation of detectable galactic lenses from future LSST survey would lead to more stringent fits of ΔfE∼10-3 , which encourages us to test the global properties of early-type galaxies at much higher accuracy.


Published in: EPJC 79 (2019) 121
Published by: Springer/Società Italiana di Fisica
DOI: 10.1140/epjc/s10052-019-6630-x
License: CC-BY-3.0



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