Projet de recherche PX/8/SS/10 (Action de recherche PX)
The present project has two facets, which basically use the same techniques:
1. Obtaining high quality images of quasar host galaxies, mainly from our own cycle 12 and 13 HST observations, complemented by the few existing ones for which an accurate PSF can be determined. Processed with our deconvolution method and combined with VLT integral field spectroscopy, these will allow a thorough analysis of the properties of quasar host galaxies.
2. Deconvolution of archive and future cycle HST images of gravitational lenses, in order to measure accurate positions of the quasar images and of the lensing galaxy/ies, as well as detecting any additional structure, such as arcs or Einstein rings usually arising from the host galaxy of the background quasar. Combined with photometric monitoring from the ground, this will allow to derive cosmological parameters such as H0 and, for sufficiently high redshift lenses, Ω and Λ, independently of the methods based on supernovae or the CMB. Furthermore, we shall model by means of the lens equation all known multiply imaged quasars showing extended structures in order to reconstruct in the source plane the real (unlensed) image of the quasar and of its host galaxy. Results at unprecedented high angular resolution will be derived thanks to the gravitational lensing magnification effect associated with the superb image quality of both the ACS in the ultraviolet and NICMOS in the infrared. Finally, these models will enable us to better trace the distribution of mass in the lens plane and contribute to a better mapping of dark matter in the Universe. These mass distributions will also provide refined gravitational lens models to improve the determination of the Hubble parameter from the time delay measurements.
Satellite(s) or flight opportunity(ies):
-HST
Field of research:
Space Sciences: Quasars, Gravitational Lenses, Cosmology
