Strong-lensing analysis of a complete sample of 12 MACS clusters at z > 0.5: Mass models and Einstein radii

Adi Zitrin, Tom Broadhurst, Rennan Barkana, Yoel Rephaeli, Narciso Benítez

Research output: Contribution to journalArticlepeer-review

127 Scopus citations


We present the results of a strong-lensing analysis of a complete sample of 12 very luminous X-ray clusters at z>0.5 using HST/ACS images. Our modelling technique has uncovered some of the largest known critical curves outlined by many accurately predicted sets of multiple images. The distribution of Einstein radii has a median value of ≈28 arcsec (for a source redshift of zs ~ 2), twice as large as other lower z samples, and extends to 55 arcsec for MACS J0717.5+3745, with an impressive enclosed Einstein mass of 7.4 × 1014M⊙. We find that nine clusters cover a very large area (>2.5 arcmin2) of high magnification (μ > 10×) for a source redshift of zs ~8, providing primary targets for accessing the first stars and galaxies.We compare our results with theoretical predictions of the standard Λ cold dark matter (ΛCDM) model which we show systematically fall short of our measured Einstein radii by a factor of ≈1.4, after accounting for the effect of lensing projection. Nevertheless, a revised analysis, once arc redshifts become available, and similar analyses of larger samples, is needed in order to establish more precisely the level of discrepancy with ΛCDM predictions.

Original languageEnglish
Pages (from-to)1939-1956
Number of pages18
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
StatePublished - 1 Jan 2011
Externally publishedYes


  • Dark matter
  • Galaxies: clusters: general
  • Galaxies: clusters: individual: MACS z 0.5 sample
  • Gravitational lensing: strong

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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