VLA measurement of the time delay in the gravitationally lensed double quasar 0957+561.
Abstract
Gravitational lens models for 0957+561 predict that there should be a time delay of roughly a year between the arrival of the two images. The authors have been monitoring the flux densities of 0957+561 A and B with the VLA for the past eight years. They present preliminary light curves of the quasar images constructed from these data. Both images show slow variation, steadily decreasing in brightness for the first few years, then gradually turning upward. The authors estimate that the time delay is between 400 and 600 days (A leading), and that the magnification ratio (A/B) of the two images is 1.45 ± 0.02.
- Publication:
-
Gravitational Lenses in Honor of Bernard F. Burke's 60th Birthday
- Pub Date:
- 1989
- Bibcode:
- 1989glhb.conf...84L
- Keywords:
-
- Gravitational Lenses: Quasars