VLA OBSERVATIONS OF THE GRAVITATIONAL LENS SYSTEM Q2237+0305

We report observations of the four-image gravitational lens system Q22 37 + 0305 with the VLA at 20 cm and 3.6 cm. The quasar was detected at both frequencies (approximate to 0.7 mJy) with a flat spectrum. All f our lensed images are clearly resolved at 3.6 cm, and the agreement of the radio and optical image positions is excellent. No radio emission is detected from the lensing galaxy, and any fifth lensed quasar imag e must be fainter than similar to 20% of the A image flux density. Sin ce the optical quasar images are variable and susceptible to extinctio n, radio flux ratios provide the best measurement of the macrolensing magnification ratios. The radio B/A and C/A image flux ratios are cons istent with the observed range of optical variations, but the D/A rati o is consistently higher in the radio than in the optical. The radio r atios are consistent with magnification ratios predicted by lens model s, and weaken alternative interpretations for Q2237+0305. More accurat e radio ratios can distinguish between the models, as well as improve our understanding of both microlensing and extinction in this system. (C) 1996 American Astronomical Society.