TY - JOUR
T1 - The surprisingly steep mass profile of A1689, from a lensing analysis of subaru images
AU - Broadhurst, T.
AU - Takada, M.
AU - Umetsu, K.
AU - Kong, X.
AU - Arimoto, N.
AU - Chiba, M.
AU - Futamase, T.
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2005/2/1
Y1 - 2005/2/1
N2 - Subaru observations of A1689 (z = 0.183) are used to derive an accurate, model-independent mass profile for the entire cluster, r ≲ 2 Mpc h -1 by combining magnification bias and distortion measurements. The projected mass profile steepens quickly with increasing radius, falling away to zero at r ∼ 1.0 Mpc h-1, well short of the anticipated virial radius. Our profile accurately matches the inner profile, r ≲ 200 kpc h-1, derived from deep Hubble Space Telescope Advanced Camera for Surveys (ACS) images. The combined ACS and Subaru information is well fitted by a Navarro-Frenk-White profile with virial mass, (1.93±0.20) × 1015 M⊙, and surprisingly high concentration, cvir = 13.7-1.1+1.4, significantly larger than theoretically expected (cvir≃4), corresponding to a relatively steep overall profile. A slightly better fit is achieved with a steep power-law model, d log Σ(θ)/d log θ ≃ -3, with a core θCi ≃ 1.′7 (rc≃210 kpc h-1), whereas an isothermal profile is strongly rejected. These results are based on a reliable sample of background galaxies selected to be redder than the cluster E/S0 sequence. By including the faint blue galaxy population, a much smaller distortion signal is found, demonstrating that blue cluster members significantly dilute the true signal for r ≲ 400 kpc h-1. This contamination is likely to affect most weak lensing results to date.
AB - Subaru observations of A1689 (z = 0.183) are used to derive an accurate, model-independent mass profile for the entire cluster, r ≲ 2 Mpc h -1 by combining magnification bias and distortion measurements. The projected mass profile steepens quickly with increasing radius, falling away to zero at r ∼ 1.0 Mpc h-1, well short of the anticipated virial radius. Our profile accurately matches the inner profile, r ≲ 200 kpc h-1, derived from deep Hubble Space Telescope Advanced Camera for Surveys (ACS) images. The combined ACS and Subaru information is well fitted by a Navarro-Frenk-White profile with virial mass, (1.93±0.20) × 1015 M⊙, and surprisingly high concentration, cvir = 13.7-1.1+1.4, significantly larger than theoretically expected (cvir≃4), corresponding to a relatively steep overall profile. A slightly better fit is achieved with a steep power-law model, d log Σ(θ)/d log θ ≃ -3, with a core θCi ≃ 1.′7 (rc≃210 kpc h-1), whereas an isothermal profile is strongly rejected. These results are based on a reliable sample of background galaxies selected to be redder than the cluster E/S0 sequence. By including the faint blue galaxy population, a much smaller distortion signal is found, demonstrating that blue cluster members significantly dilute the true signal for r ≲ 400 kpc h-1. This contamination is likely to affect most weak lensing results to date.
KW - Cosmology: observations
KW - Galaxies: clusters: individual (A1689)
KW - Gravitational lensing
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U2 - 10.1086/428122
DO - 10.1086/428122
M3 - Article
AN - SCOPUS:17044390851
VL - 619
SP - L143-L146
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2 II
ER -