LY alpha and C IV Narrow-Band Imaging of the Gravitational Lens 2237+030
Abstract
Narrow-band (Lyα 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 ~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 Lyα data, a lower limit to the ratio of the size of the broad-line region to the nonthermal continuum region may be set at ~40. Resolved Lyα 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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1992
- DOI:
- 10.1086/186567
- Bibcode:
- 1992ApJ...398L..21Y
- Keywords:
-
- Carbon;
- Gravitational Lenses;
- Lyman Alpha Radiation;
- Quasars;
- Active Galactic Nuclei;
- Emission Spectra;
- Spectral Line Width;
- Astrophysics;
- COSMOLOGY: GRAVITATIONAL LENSING;
- GALAXIES: QUASARS: EMISSION LINES;
- GALAXIES: QUASARS: INDIVIDUAL ALPHANUMERIC: 2237;
- 030