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A CFH12k lensing survey of X-ray luminous galaxy clusters I : weak lensing methodology

Bardeau, S.; Kneib, J.-P.; Czoske, O.; Soucail, G.; Smail, I.; Ebeling, H.; Smith, G.P.

A CFH12k lensing survey of X-ray luminous galaxy clusters I : weak lensing methodology Thumbnail


Authors

S. Bardeau

J.-P. Kneib

O. Czoske

G. Soucail

H. Ebeling

G.P. Smith



Abstract

We describe the weak lensing methodology we have applied to multi-colour CFH12k imaging of a homogeneouslyselected sample of luminous X-ray clusters at z ∼ 0.2. The aim of our survey is to understand the variation in cluster structure and dark matter profile within rich clusters. The method we describe converts a fully reduced CFH12k image into constraints on the cluster mass distribution in two steps: (1) determination of the “true” shape of faint (lensed) galaxies, including object detection, point spread function(PSF) determination, galaxy shape measurement with errors; (2) conversion of the faint galaxy catalogue into reliable mass constraints using a range of 1D and 2D lensing techniques. Mass estimates are derived independently from each of the three images taken in separate filters to quantify the systematic uncertainties. Finally, we compare the cluster mass model to the light distribution of cluster members as derived from our imaging data. To illustrate the method, we apply it to the well-studied cluster Abell 1689 (z = 0.184). In this cluster, we detect the gravitational shear signal out to ∼3Mpc at >3-σ significance. The two-dimensional mass reconstruction has a ∼10-σ significance peak centered on the brightest cluster galaxy. The weak lensing profile is well fitted by a NFW mass profile with M200 = 14.1+6.3 −4.7 × 1014 M, and c = 3.5+0.5 −0.3 (χ2 = 0.33), or by a power law profile with q = 0.75 ± 0.07 and θE = 14.6 ± 0.3 (χ2 = 0.64). The mass-to-light ratio is found to be almost constant with radius with a mean value of M/LR = 150 h (M/L). We compare these results to other weak lensing analyses of Abell 1689 from the literature and find good agreements in terms of the shear measurement as well as the final mass estimate.

Citation

Bardeau, S., Kneib, J., Czoske, O., Soucail, G., Smail, I., Ebeling, H., & Smith, G. (2005). A CFH12k lensing survey of X-ray luminous galaxy clusters I : weak lensing methodology. Astronomy & Astrophysics, 434(2), 433-448. https://doi.org/10.1051/0004-6361%3A20041643

Journal Article Type Article
Publication Date May 1, 2005
Deposit Date May 28, 2013
Publicly Available Date Mar 29, 2024
Journal Astronomy and astrophysics.
Print ISSN 0004-6361
Electronic ISSN 1432-0746
Publisher EDP Sciences
Peer Reviewed Peer Reviewed
Volume 434
Issue 2
Pages 433-448
DOI https://doi.org/10.1051/0004-6361%3A20041643
Keywords Gravitational lensing, Galaxies, Clusters, Abell 1689.

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Copyright Statement
Reproduced with permission from Astronomy & Astrophysics, © ESO





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