Key points are not available for this paper at this time.
As part of a program of high spatial resolution imaging of gravitationally lensed sources in the visible and infrared, images of 2237+030 were obtained in the Gunn r and infrared J, H, K, and 3. 3 micron filters. The results of the photometry of the four bright quasar components provide evidence of extinction through the lens and a determination of the extinction law in the galaxy is made. The energy distribution shows evidence of a sharp decrease of the spectral index α (fᵥ_ is proportional to valpha^) at wavelengths longer than a rest wavelength of 1 micron. Assuming that microlensing amplification in the infrared is of similar strength as in the visible, the data constrain the suggested microlensing event of 1988 August-September to a time scale of 100 days.
Nadeau et al. (Thu,) studied this question.