Support for the Gravitational Lens Interpretation of SBS 0909+532

Oscoz, A.; Serra-Ricart, M.; Mediavilla, E.; Buitrago, J.; Goicoechea, Luis Julian
Bibliographical reference

Astrophysical Journal Letters v.491, p.L7

Advertised on:
12
1997
Number of authors
5
IAC number of authors
4
Citations
38
Refereed citations
36
Description
The system SBS 0909+532A, B is a double consisting of a quasar and a fainter component that was, until now, spectroscopically unresolved. Spectra taken in good seeing conditions ( {FWHM}=1^{''} ) with the 4.2 m William Herschel Telescope separate the A and B components, showing that both are quasars with the same redshift, z=1.377 , and identical spectra. Consequently, this supports the gravitational lens interpretation of SBS 0909+532. The Mg II lambda lambda 2796, 2803 doublet is found in absorption at the same redshift ( z=0.83 ) in both components, although the equivalent width of the faintest one is 3 times stronger. We discuss the possibility that these absorption features arise from the photometrically unidentified lensing galaxy. We have also observed another double system, Q1222+226, which was recently reported to be a gravitationally lensed quasar. Comparison of the spectra of both components indicates that Q1222+226 is in fact composed of a quasar and a star.