LoCuSS: Subaru Weak Lensing Study of 30 Galaxy Clusters

N Okabe, M Takada, K Umetsu, T Futamase, Graham Smith

Research output: Contribution to journalArticle

235 Citations (Scopus)

Abstract

We use high-quality Subaru/Suprime-Cam imaging data to conduct a detailed weak lensing study of the distribution of dark matter in a sample of 30 X-ray luminous galaxy clusters at 0.15 6 x 10(14) h(-1) M-circle dot) mass bins. We also used individual cluster NFW model fits to investigate the relationship between the cluster mass and the concentration, finding that the concentration (c(vir)) decreases with increasing cluster mass The best-fit c(vir)-M-vir relation is: c(vir)(M-vir) = 8.75(-2.89)(+4.13) x (M-vir/10(14) h(-1) M-circle dot)(-alpha) with a alpha approximate to 0.40 +/- 0.19: i.e., a non-zero slope is detected at 2 sigma significance. This relation gives a concentration of c(vir) = 3.48(-1.15)(+1.65) for clusters with M-vir = 10(15) h(-1) M-circle dot, which is inconsistent at 4 sigma significance with the values of c(vir) similar to 10 reported for strong-lensing-selected clusters. We have found that the measurement error on the cluster mass is smaller at higher over-densities, Delta similar or equal to 500-2000, than at the virial over-density, Delta(vir) similar or equal to 110; typical fractional errors at Delta similar or equal to 500-2000 are improved to sigma(M-Delta)/M-Delta similar or equal to 0.1-0.2 compared with 0.2-0.3 at Delta(vir). Furthermore, comparing the 3D spherical mass with the 2D cylinder mass, obtained from the aperture mass method at a given aperture radius, theta(Delta), reveals M-2D(<theta(Delta))/M-3D(<r(Delta) = D-1 theta(Delta)) similar or equal to 1.46 and 1.32 for Delta = 500 and Delta(vir), respectively. The amplitude of this offset agrees well with that predicted by integrating an NFW model of cluster-scale halos along the line-of-sight.
Original languageEnglish
Pages (from-to)811-870
Number of pages60
JournalPublications of the Astronomical Society of Japan
Volume62
Issue number3
Publication statusPublished - 1 Jan 2010

Keywords

  • galaxies: clusters
  • gravitational lensing
  • dark matter
  • cosmology: observations

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