1980/10/01 by P. Young, James E. Gunn, J. B. Oke +2 · 2 citations
Physics and Astronomy · #Galaxies: Formation, Evolution, Phenomena #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations
paper · doi:10.1086/158365
openalex publication_date 1980/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Deep CCD pictures show a rich cluster of galaxies around the double quasar Q0957 + 561 as well as faint extended wings on the image of the southern quasar. Calculations of gravitational imaging by King model mass distributions show that the cluster and the brightest galaxy together, acting as a gravitational lens on the light from a single, more distant QSO, can easily reproduce all of the present observations. It is concluded that the double quasar is almost certainly the multiple image of a single object produced by a gravitational lens.