Sharif University of Technology - Weekly Cosmology Seminar ( Sunday- 15 January 2017 - 26 Day 1395)
دانشکده فیزیک دانشگاه صنعتی شریف
سمینار هفتگی گروه کیهان شناسی
Time delay analysis of strongly lensed systems
Korea Astronomy and Space Science Institute, South Korea
Strong gravitational lensing systems contain a wealth of information that can be used to estimate the expansion history of the universe. The light rays from different images of a source quasar experience different gravitational potentials and optical paths which result a time delay in the associated light curves. A reliable estimation of the time delay has crucial role in the process of expansion history estimation. In this talk we describe our proposed algorithm for time delay estimation which shows outstanding results in the Time Delay Challenge (TDC). This algorithm consists of the smoothing and cross-correlation methodologies as well as a quick way for error estimation. In continue we explain the modified version of this algorithm which recently we have developed. In this version we introduce a new time delay estimator which includes weighted cross-correlation and some other changes in the procedure of estimation. The modified algorithm shows more precise results on TDC simulated data. At the end we discuss the estimation of time delay related to the light curves of the lensed quasar SDSS J1001+5027 system and compare our results with the time delays obtained by different group of researchers for the same system.
یکشنبه 26 دی ماه 1395، ساعت 15:00
دانشکده فیزیک، تالار پرتوی