MEASURING THE TIME DELAYS IN GRAVITATIONALLY LENSED QUASARS IN THE PRESENCE OF MICROLENSING

Abstract

A method to measure the time delays in gravitationally lensed quasars is proposed, which provides a simple and transparent procedure to eliminate the effects of microlensing events. The procedure is based on fundamental properties of representation of quadratically integrable functions by their expansion in orthogonal polynomials. The method is tested on the seven-year duration light curves of the gravitationally lensed quasar НЕ 0435-223. The corresponding photometry was downloaded from the Strasbourg Astronomical Data Center archive. The analysis of time delay estimates in the НЕ 0435-1223 system, as well as comparison with the results published by other authors, are presented.

Keywords

• time delays
• quasar
• microlensing
• light curves gravitational lensing
• ortogonal polynomial