Journal Article

A gravitationally lensed quasar with quadruple images separated by 14.62 arcseconds

Richards, Gordon T., Gunn, James E., Johnston, David E., Bahcall, Neta A., Becker, Robert H., Rix, Hans-Walter, Chiu, Kuenley, Zheng, Wei, Nichol, Robert C., Lamb, Don Q., Inada, Naohisa, Turner, Edwin L., Hennawi, Joseph F., Ivezić, Željko, McKay, Timothy A., Oguri, Masamune, Frieman, Joshua A., Kent, Stephen M., Castander, Francisco J., Schneider, Donald P., York, Donald G., Sheldon, Erin Scott, Keeton, Charles R., Ichikawa, Shin-Ichi, Strauss, Michael A., Eisenstein, Daniel J., Brinkmann, J., Pindor, Bartosz, Suto, Yasushi, Gregg, Michael D., Annis, James, Fukugita, Masataka

2003

Overview

Gravitational lensing is a powerful tool for the study of the distribution of dark matter in the Universe. The cold-dark-matter model of the formation of large-scale structures (that is, clusters of galaxies and even larger assemblies) predicts 1 , 2 , 3 , 4 , 5 , 6 the existence of quasars gravitationally lensed by concentrations of dark matter 7 so massive that the quasar images would be split by over 7 arcsec. Numerous searches 8 , 9 , 10 , 11 for large-separation lensed quasars have, however, been unsuccessful. All of the roughly 70 lensed quasars known 12 , including the first lensed quasar discovered 13 , have smaller separations that can be explained in terms of galaxy-scale concentrations of baryonic matter. Although gravitationally lensed galaxies 14 with large separations are known, quasars are more useful cosmological probes because of the simplicity of the resulting lens systems. Here we report the discovery of a lensed quasar, SDSS J1004 + 4112, which has a maximum separation between the components of 14.62 arcsec. Such a large separation means that the lensing object must be dominated by dark matter. Our results are fully consistent with theoretical expectations 3 , 4 , 5 based on the cold-dark-matter model.

• Publisher: Nature Publishing Group UK,Nature Publishing,Nature Publishing Group
• Subject: Astronomy / Characteristics and properties of external galaxies and extragalactic objects / Dark matter (stellar, interstellar, galactic, and cosmological) / Earth, ocean, space / Exact sciences and technology / Fundamental astronomy and astrophysics. Instrumentation, techniques, and astronomical observations / Gravitational lenses and luminous arcs / Humanities and Social Sciences / letter / multidisciplinary / Quasars / Quasars. Active or peculiar galaxies, objects, and systems / Science / Science (multidisciplinary) / Stellar systems. Galactic and extragalactic objects and systems. The universe