A direct empirical proof of the existence of dark matter

Douglas Clowe, Maruša Bradač, Anthony H. Gonzalez, Maxim Markevitech, Scott W. Randall, Christine Jones, Dennis Zaritsky

Research output: Contribution to journalArticlepeer-review

1264 Scopus citations


We present new weak-lensing observations of IE 0657-558 (z = 0.296), a unique cluster merger, that enable a direct detection of dark matter, independent of assumptions regarding the nature of the gravitational force law. Due to the collision of two clusters, the dissipationless stellar component and the fluid-like X-ray-emitting plasma are spatially segregated. By using both wide-field ground-based images and HST/ACS images of the cluster cores, we create gravitational lensing maps showing that the gravitational potential does not trace the plasma distribution, the dominant baryonic mass component, but rather approximately traces the distribution of galaxies. An 8 σ significance spatial offset of the center of the total mass from the center of the baryonic mass peaks cannot be explained with an alteration of the gravitational force law and thus proves that the majority of the matter in the system is unseen.

Original languageEnglish (US)
Pages (from-to)L109-L113
JournalAstrophysical Journal
Issue number2 II
StatePublished - Sep 10 2006


  • Dark matter
  • Galaxies: clusters: individual (1E 0657-558)
  • Gravitational lensing

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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