English

CLASH: Weak-Lensing Shear-and-Magnification Analysis of 20 Galaxy Clusters

Cosmology and Nongalactic Astrophysics 2015-06-19 v3 Astrophysics of Galaxies

Abstract

We present a joint shear-and-magnification weak-lensing analysis of a sample of 16 X-ray-regular and 4 high-magnification galaxy clusters at 0.19<z<0.69 selected from the Cluster Lensing And Supernova survey with Hubble (CLASH). Our analysis uses wide-field multi-color imaging, taken primarily with Suprime-Cam on the Subaru Telescope. From a stacked shear-only analysis of the X-ray-selected subsample, we detect the ensemble-averaged lensing signal with a total signal-to-noise ratio of ~25 in the radial range of 200 to 3500kpc/h. The stacked tangential-shear signal is well described by a family of standard density profiles predicted for dark-matter-dominated halos in gravitational equilibrium, namely the Navarro-Frenk-White (NFW), truncated variants of NFW, and Einasto models. For the NFW model, we measure a mean concentration of c200c=4.010.32+0.35c_{200c}=4.01^{+0.35}_{-0.32} at M200c=1.340.09+0.101015MM_{200c}=1.34^{+0.10}_{-0.09} 10^{15}M_{\odot}. We show this is in excellent agreement with Lambda cold-dark-matter (LCDM) predictions when the CLASH X-ray selection function and projection effects are taken into account. The best-fit Einasto shape parameter is αE=0.1910.068+0.071\alpha_E=0.191^{+0.071}_{-0.068}, which is consistent with the NFW-equivalent Einasto parameter of 0.18\sim 0.18. We reconstruct projected mass density profiles of all CLASH clusters from a joint likelihood analysis of shear-and-magnification data, and measure cluster masses at several characteristic radii. We also derive an ensemble-averaged total projected mass profile of the X-ray-selected subsample by stacking their individual mass profiles. The stacked total mass profile, constrained by the shear+magnification data, is shown to be consistent with our shear-based halo-model predictions including the effects of surrounding large-scale structure as a two-halo term, establishing further consistency in the context of the LCDM model.

Keywords

Cite

@article{arxiv.1404.1375,
  title  = {CLASH: Weak-Lensing Shear-and-Magnification Analysis of 20 Galaxy Clusters},
  author = {Keiichi Umetsu and Elinor Medezinski and Mario Nonino and Julian Merten and Marc Postman and Massimo Meneghetti and Megan Donahue and Nicole Czakon and Alberto Molino and Stella Seitz and Daniel Gruen and Doron Lemze and Italo Balestra and Narciso Benitez and Andrea Biviano and Tom Broadhurst and Holland Ford and Claudio Grillo and Anton Koekemoer and Peter Melchior and Amata Mercurio and John Moustakas and Piero Rosati and Adi Zitrin},
  journal= {arXiv preprint arXiv:1404.1375},
  year   = {2015}
}

Comments

Accepted by ApJ on 11 August 2014. Textual changes to improve clarity (e.g., Sec.3.2.2 "Number-count Depletion", Sec.4.3 "Shape Measurement", Sec.4.4 "Background Galaxy Selection"). Results and conclusions remain unchanged. For the public release of Subaru data, see http://archive.stsci.edu/prepds/clash/