A novel approach for extracting time-delays from lightcurves of lensed quasar images
English
Burud, I.[Institut d'Astrophysique et de Géophysique, Université de Liège, Avenue de Cointe 5, 4000 Liège, Belgium; Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA,]
Magain, Pierre[Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image >]
Sohy, Sandrine[Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image >]
Hjorth, J.[Astronomical Observatory, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark]
[en] METHODS: DATA ANALYSIS ; GRAVITATIONAL LENSING
[en] We present a new method to estimate time delays from light curves of lensed quasars. The method is based on chi [SUP]2[/SUP] minimization between the data and a numerical model light curve. A linear variation can be included in order to correct for slow long-term microlensing effects in one of the lensed images. An iterative version of the method can be applied in order to correct for higher-order microlensing effects. The method is tested on simulated light curves. When higher-order microlensing effects are present, the time delay is best constrained with the iterative method. Analysis of a published data set for the lensed double Q 0957+561 yields results in agreement with other published estimates.
[Institut d'Astrophysique et de Géophysique, Université de Liège, Avenue de Cointe 5, 4000 Liège, Belgium; Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA,]
