LY-ALPHA AND C-IV NARROW-BAND IMAGING OF THE GRAVITATIONAL LENS-2237+030

Narrow-band (Lyoalpha and C IV) and broad-band imaging of the gravitational lens system 2237 + 030 has revealed a strong microlensing event in component B in 1991 with an amplitude of approximately 0.5 mag. The images in the emission-line bands show considerably less magnification than those in the continuum bands. This difference in magnification between the emission-line and continuum regions strongly suggests that the variation is due to microlensing, assuming a standard model for quasars in which the emission-line region is much larger than the continuum source. These observations provide a direct estimate of the size ratio of the two regions. From the Lyalpha data, a lower limit to the ratio of the size of the broad-line region to the nonthermal continuum region may be set at almost-equal-to 40. Resolved Lyalpha emission has been detected near component D, as well as possibly near the center of the Einstein circle. These features are consistent with a model in which a resolved star-forming region in the quasar host galaxy or associated companion galaxy is lensed by the foreground galaxy. The C IV data were not of sufficient S/N to confirm these features.