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. We have been monitoring the flux densities of 0957+561 A and B with the VLA for the past eight years. Here we 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. We 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 f 0.02.
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© 1989 Springer-Verlag
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Lehár, J., Hewitt, J.N., Roberts, D.H. (1989). VLA measurement of the time delay in the gravitationally lensed double quasar 0957+561. In: Moran, J.M., Hewitt, J.N., Lo, K.Y. (eds) Gravitational Lenses. Lecture Notes in Physics, vol 330. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-51061-3_42
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DOI: https://doi.org/10.1007/3-540-51061-3_42
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