May 27, 2019 to June 5, 2019
Europe/Paris timezone

G. Weerasekara: The effect of peculiar motion of galaxies when calculating the gravitational lensing time delay

May 28, 2019, 6:50 PM
Amphitheatre (Cargèse)



Institut d’Etudes Scientifiques de Cargèse Menasina F-20130 CARGÈSE


Mr Gihan Weerasekara (University of Colombo)


An intervening galaxy acts like a gravitational lens and produces multiple images of a single source such as a more remote galaxy. In such a scenario the source, the lens and the observer all have peculiar motions in any random direction in addition to the overall expansion of the universe due to the dark energy. There is a difference in light arriving times from images of a single source, known as the time delay. In calculating such time delays, the peculiar motions of the source, the lens and the observer are generally neglected. In this study, realistic time delays are calculated considering such peculiar motions. The results show that peculiar motions contribute to measurable differences to the observed time delays.

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