VLBI Observations of the O957 + 561 Gravitational Lens Systems (review)
Abstract
A series of VLBI observations of the gravitational lens system 0957 + 561 at a wavelength of 13 cm has yielded the positions of the A and B images, the relative magnification of their largest discernible radio structures, and the time variability of their smallest discernible radio structures. These observations have also allowed upper limits to be placed on the flux density of an expected third image. The positions and relative magnification of the A and B images provide new information with which to constrain models of the lens that forms the images. The detection of variations in the flux densities of the cores of A and B suggests that observations at shorter wavelengths may reveal superluminal motion, which may in turn provide a means to measure the relative time delay.
- Publication:
-
The Impact of VLBI on Astrophysics and Geophysics
- Pub Date:
- 1988
- Bibcode:
- 1988IAUS..129..201G
- Keywords:
-
- Astronomical Models;
- Gravitational Lenses;
- Quasars;
- Very Long Base Interferometry;
- Brightness Distribution;
- Centimeter Waves;
- Computational Astrophysics;
- Magnification;
- Variability