Context. An excess of galaxy–galaxy strong lensing (GGSL) in galaxy clusters compared to expectations from the ? cold-dark-matter (CDM) cosmological model has recently been reported. Theoretical estimates GGSL probability are based on analysis numerical hydrodynamical simulations ?CDM cosmology. Aims. We quantify impact resolution and active galactic nucleus (AGN) feedback scheme adopted predic...

The multi-band photometry of the VOICE imaging data, overlapping with 4.9 deg 2 Chandra Deep Field South (CDFS) area, enables both shape measurement and photometric redshift estimation to be two essential quantities for weak lensing analysis. depth mag AB is up 26.1 (5 σ limiting) in r -band. We estimate excess surface density (ESD; ΔΣ) based on galaxy–galaxy measurements around galaxies at low...

Gravitational lensing is an important tool for probing the mass distribution of galaxies. In this letter we report the discovery of a new quadruple lens HST 1411+5211 found in archived WFPC2 images of the galaxy cluster CL140933+5226. If the galaxy is a cluster member then its redshift is z = 0.46. The images of the source appear unresolved in the WFC implying that the source is a quasar. We ha...