A team of astronomers led by Joseph Hennawi of the Max Planck Institute for Astronomy, using the W.M. Keck observatory in Hawaii, have discovered the first quadruple quasar: four quasars with approximately the same redshift of about z ~ 2 and located on the sky in close proximity. The online article1 from Max Planck Institute is titled “Quasar quartet puzzles scientists” with the subtitle “Astronomers must rethink models about the development of large-scale cosmic structures.” This is a discovery of the first known group of four quasars with the same redshift found in the same location on the sky. A research paper has been accepted for publication in the journal Science and a preprint is now available.2
The quartet resides in one of the most massive structures ever discovered in the distant universe, and is surrounded by a giant nebula of cool dense gas. Either the discovery is a one-in-ten-million coincidence, or cosmologists need to rethink their models of quasar evolution and the formation of the most massive cosmic structures.1
