Unusual radio source MG1131+0456: a possible Einstein ring
Abstract
We report the discovery of extremely unusual structure in the radio source MG1131 + 0456. In a radio map with sub~arc$econd resolution the object appears as an elliptical ring of emission accompanied by a pair of more compact sources, nearly diametrically opposed and offset ~0.3 arc s to the south-west of the ring. There is a faint, slightly extended, optical counterpart. In its spectrum we detect a continuum but no emission lines; therefore the redshift of the counterpart is unknown. The radio morphology suggests that this source may be an example of an 'Einstein ring'1, a highly symmetric case of grayitational lensing in which the source is imaged into a ring. Other explanations that we consider are excluded by the data. Another possibility is that MG1131 +0456 represents a new type of (unlensed) astronomical object.
- Publication:
-
Nature
- Pub Date:
- June 1988
- DOI:
- 10.1038/333537a0
- Bibcode:
- 1988Natur.333..537H
- Keywords:
-
- Extragalactic Radio Sources;
- Gravitational Lenses;
- Radio Galaxies;
- Gravitational Fields;
- Infrared Sources (Astronomy);
- Very Large Array (Vla);
- Astrophysics