Is 3C324 the first gravitationally lensed giant galaxy?
Abstract
The radiogalaxy 3C324 has recently raised considerable interest as one of the most distant (redshift z = 1.206) and luminous known galaxies. Here we report new observations of this object at Canada-France-Hawaii Telescope which confirm our previous predictions of the presence of an intervening gravitational lens. First, a multiple structure is revealed by our charge-coupled device (CCD) broadband imagery. Second, following our previous identification in the 3C324 spectrum of an additional line system at z=0.84, subsequent CCD observation through interferential filters were planned. In a wavelength range corresponding to an emission line at z=0.84 only the central component is detected, while only outer components are seen in a range corresponding to a line redshifted by z=1.206. These observations are interpreted as the first example of gravitational multiple imaging of a giant radiogalaxy by a foregound object. So galaxy 3C324 seems to be a gravitational mirage-though further spectroscopic observations will be needed to establish whether the two images have similar spectra.
- Publication:
-
Nature
- Pub Date:
- March 1987
- DOI:
- 10.1038/326268a0
- Bibcode:
- 1987Natur.326..268L
- Keywords:
-
- Astronomical Spectroscopy;
- Galactic Structure;
- Gravitational Lenses;
- Radio Galaxies;
- Charge Coupled Devices;
- Interference Grating;
- Line Spectra;
- Luminosity;
- Red Shift;
- Astrophysics