The SL2S Galaxy-scale Gravitational Lens Sample. I. The alignment of mass and light in massive early-type galaxies at z=0.2-0.9Report as inadecuate




The SL2S Galaxy-scale Gravitational Lens Sample. I. The alignment of mass and light in massive early-type galaxies at z=0.2-0.9 - Download this document for free, or read online. Document in PDF available to download.

1 IAP - Institut d-Astrophysique de Paris 2 Physics Department, UCSB 3 Astrophysics, Oxford 4 KIPAC - KIPAC, Stanford 5 Astrophysics, Melbourne

Abstract : We study the relative alignment of mass and light in a sample of 16 massive early-type galaxies at z=0.2-0.9 that act as strong gravitational lenses. The sample was identified from deep multi-band images obtained as part of the Canada France Hawaii Telescope Legacy Survey as part of the Strong Lensing Legacy Survey SL2S. Higher resolution follow-up imaging is available for a subset of 10 systems. We construct gravitational lens models and infer total enclosed mass, elongation, and position angle of the mass distribution. By comparison with the observed distribution of light we infer that there is a substantial amount of external shear with mean value $\langle\gamma { m ext} angle= 0.12 \pm 0.05$, arising most likely from the environment of the SL2S lenses. In a companion paper, we combine these measurements with follow-up Keck spectroscopy to study the evolution of the stellar and dark matter content of early-type galaxies as a function of cosmic time.

keyword : galaxies: fundamental parameters gravitational lensing: strong





Author: Raphael Gavazzi - Tommaso Treu - Philip Marshall - Florence Brault - Andrea Ruff -

Source: https://hal.archives-ouvertes.fr/



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