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Further Investigation Of The Time Delay, Magnification Ratios, And Variability In The Gravitational Lens 0218 + 357, A. S. Cohen, J. N. Hewitt, C. B. Moore, Deborah B. Haarsma

University Faculty Publications and Creative Works

High-precision VLA flux density measurements for the lensed images of 0218 + 357 yield a time delay of 10.1 +1.5-1.6 days (95% confidence). This is consistent with independent measurements carried out at the same epoch by Biggs and colleagues in 1999, lending confidence to the robustness of the time delay measurement. However, since both measurements make use of the same features in the light curves, it is possible that the effects of unmodeled processes, such as scintillation or microlensing, are biasing both time delay measurements in the same way. Our time delay estimates result in confidence intervals that are somewhat …