Gravitational lensing potential reconstruction in quadruply imaged systems
Dipartimento di Fisica "E.R. Caianiello" , Università di Salerno and INFN, Sezione di Napoli, Gruppo Collegato di Salerno, Via S. Allende, 84081 Baronissi (Salerno), Italy
2 Dipartimento di Scienze Fisiche, Università di Napoli and INFN, Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Via Cinthia, Edificio N, 80126 Napoli, Italy
Corresponding author: V. F. Cardone, Vincenzo.Cardone@na.infn.it
Accepted: 29 August 2001
We develop a semi-analytical method to reconstruct the lensing potential in quadruply imaged gravitational lens systems. Assuming that the potential belongs to a broad class of boxy non-elliptical models, we show how it is possible to write down a system of equations which can be numerically solved to recover the potential parameters directly from image positions and using physical constraints. We also describe a code developed to search for solutions of the system previously found and test it on simulated cases. Finally, we apply the method to the quadruple lens PG 1115+080 which allows us to get also an estimate of the Hubble constant H0 from the measured time delay as .
Key words: gravitational lensing / cosmology: distance scale / galaxies: structure / quasars: individual: PG 1115+080
© ESO, 2001