TY - JOUR

T1 - Strong-lensing analysis of a complete sample of 12 MACS clusters at z > 0.5

T2 - Mass models and Einstein radii

AU - Zitrin, Adi

AU - Broadhurst, Tom

AU - Barkana, Rennan

AU - Rephaeli, Yoel

AU - Benítez, Narciso

PY - 2011/1

Y1 - 2011/1

N2 - 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.

AB - 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.

KW - Dark matter

KW - Galaxies: clusters: general

KW - Galaxies: clusters: individual: MACS z 0.5 sample

KW - Gravitational lensing: strong

UR - http://www.scopus.com/inward/record.url?scp=79951713001&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2966.2010.17574.x

DO - 10.1111/j.1365-2966.2010.17574.x

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AN - SCOPUS:79951713001

SN - 0035-8711

VL - 410

SP - 1939

EP - 1956

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 3

ER -