Infrared observations of the dark matter lens candidate Q2345+007

Brian Mcleod, Marcia Rieke, Daniel Weedman

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Deep K-band observations are presented of the double image quasar Q2345+007. This has the largest separation (7″.1) of any quasar image pair considered as gravitationally lensed, so the required lens is massive (1013 M). No lens has been detected in previous deep images at visible wavelengths, and we find no lens to limiting K magnitude 20.0 in the infrared image. This constrains any lens to being much less luminous than brightest cluster galaxies, while the lens must be much more massive than such galaxies to produce the observed separation. Because spectral data indicate exceptional intrinsic similarity in the quasar image components, this pair remains as the most intriguing example of an observed configuration requiring the presence of massive, concentrated dark matter acting as a gravitational lens.

Original languageEnglish (US)
Pages (from-to)528-532
Number of pages5
JournalAstrophysical Journal
Issue number2
StatePublished - Oct 1 1994


  • Gravitational lensing
  • Infrared: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Infrared observations of the dark matter lens candidate Q2345+007'. Together they form a unique fingerprint.

Cite this