Bibcode
                                    
                            DOI
                                    
                            Oscoz, A.; Serra-Ricart, M.; Mediavilla, E.; Buitrago, J.; Goicoechea, Luis Julian
    Bibliographical reference
                                    Astrophysical Journal Letters v.491, p.L7
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                        12
            
                        1997
            
  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.