Spatially Resolved Spectroscopy of Lyman-Alpha and C IV in the Gravitational Lens 2237+030

Spatially resolved, long-slit spectra of components A and B of the gravitational lens system 2237 + 030 have been obtained in Lyα and C IV at the CFHT. For Lyα, A and B are clearly resolved in both the emission line and continuum with almost no contamination from components C or D. The spectrogram of the two components shows an absorption trough situated ~255 km s^-1^ redward of the broad emission-line centroid which contains a narrow emission feature lying spatially between the two components. There are, however, two distinct absorption systems in both the N V and C IV doublets which are matched in redshift. We propose that this partially resolved Lyα emission component, spatially distinct from the quasars, arises from the gravitational lensing of a massive compact star-forming region that is associated with either the host galaxy or a companion galaxy and which also likely produces the absorption systems. The Lyα absorption clouds have sufficiently high column density that the two profiles merge, whereas the lower column densities in N V and C IV give rise to separate absorption lines. The C IV spectrogram shows neither this narrow emission component nor the double-peaked structure so evident in Lyα. This is probably the result of contamination from component D caused by a slight misalignment of the slit and the fact that the Lyα/C IV intensity ratio is larger in star-forming regions than in active galactic nuclei. The spatial structure of the narrow emission feature within the Lyα absorption systems is consistent with a model in which the emission-line source lies on a caustic in the source plane, producing lensed features in the image plane both inside and outside the Einstein ring.