Direct 2.2 mu-m image of the gravitationally lensed quasar Q 0957+561.
Abstract
We report on a good seeing IR image in the K (2.2 micron) band of the twin quasar QSO 0957+561 A, B. The image reveals that at this wavelength the B component is four times brighter than A and is clearly extended. The component B is unambiguously identified as the merging of the QSO image B and of the lensing galaxy found at visible and radio wavelength, 0.76" N-E of the quasar image. The set of data is consistent with the superposition of a point source and an extended galaxy. The brightness profile of the galaxy, measured up to a diameter of 6", is much less affected by the quasar image than in the visible. It can be fitted by a spiral disk distribution, but that would be of abnormally large dimensions and luminosity. A much better fit is obtained assuming a giant cD elliptical galaxy (brightest member of the cluster) with an extended halo. The size and importance of the fitted halo are typical of this class of galaxy.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 1990
- Bibcode:
- 1990A&A...232...16G
- Keywords:
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- Elliptical Galaxies;
- Gravitational Lenses;
- Infrared Imagery;
- Quasars;
- Infrared Astronomy;
- Infrared Radiation;
- Seeing (Astronomy);
- Astrophysics