MG 1654+1346: an Einstein Ring Image of a Quasar Radio Lobe
Abstract
The unusual radio morphology of MG 1654 + 1346 suggests that it is an excellent candidate for an Einstein Ring gravitational lens. VLA radio images with 0.4" resolution reveal two components, each resolved, separated by ~7". The brighter component has a ring-shaped structure with an angular diameter of 2.1" +/- 0.2", and there are approximately symmetric intensity variations (in particular, two resolved "bright spots") around the circumference of the ring. CCD images in the g and r filters show two optical counterparts: a 19 mag galaxy coincident with the center of the radio ring, and a blue, 21 mag stellar object located ~3" northeast of this galaxy (the blue object is positioned between the two radio components). The galaxy has a redshift of 0.254 (based on several absorption features) and the stellar object is a quasar with a redshift of 1.74 (based on two broad emission lines). A simple schematic model that represents the source as a quasar with two extended radio lobes and the lens as an elliptical potential at the position of the galaxy provides a reasonable, but not perfect, reproduction of the radio observations. The mass-to-light ratio of the material projected inside of the ring is 19 (for H_0_ = 100), and the indicated one-dimensional velocity dispersion is roughly 220 km s^-1^. More extensive radio observations, improved optical imaging, and numerical lens models should allow the mass and mass-to-light ratio distribution in the lensing galaxy to be determined accurately and in some detail.
- Publication:
-
The Astronomical Journal
- Pub Date:
- May 1989
- DOI:
- 10.1086/115071
- Bibcode:
- 1989AJ.....97.1283L
- Keywords:
-
- Galactic Clusters;
- Gravitational Lenses;
- Quasars;
- Astrometry;
- Charge Coupled Devices;
- Mass To Light Ratios;
- Radio Observation;
- Red Shift;
- Very Large Array (Vla);
- Astronomy;
- QUASARS;
- GRAVITATION