For refcode 2010PASJ...62..811O: Retrieve 30 NED objects in this reference. Please click here for ADS abstract
NED Abstract
Copyright by Astronomical Society of Japan.
2010PASJ...62..811O
LoCuSS: Subaru Weak Lensing Study of 30 Galaxy Clusters
Okabe, Nobuhiro; Takada, Masahiro; Umetsu, Keiichi; Futamase, Toshifumi;
Smith, Graham P.
Abstract. We use highquality Subaru/SuprimeCam imaging data to conduct a
detailed weak lensing study of the distribution of dark matter in a sample
of 30 Xray luminous galaxy clusters at 0.15 <= z <= 0.3. A weak lensing
signal is detected at high statistical significance in each cluster, the
total signaltonoise ratio of the detections ranging from 5 to 13.
Comparing spherical models to the tangential distortion profiles of the
clusters individually, we are unable to discriminate statistically between
a singular isothermal sphere (SIS) and Navarro, Frenk, and White (NFW)
models. However, when the tangential distortion profiles are combined and
then models are fitted to the stacked profile, the SIS model is rejected
at 6{sigma} and 11{sigma}, respectively, for low (M_vir_ < 6 x
10^14^h^1^M_{sun}_) and high (M_vir_ > 6 x 10^14^h^1^M_{sun}_) 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
(M_vir_). The bestfit c_vir_M_vir_ relation is: c_vir_(M_vir_) =
8.75^+4.13^_2.89_ x (M_vir_/10^14^h^1^M_{sun}_)^{alpha}^ with
{alpha}~=0.40+/0.19: i.e., a nonzero slope is detected at 2{sigma}
significance. This relation gives a concentration of c_vir_ =
3.48^+1.65^_1.15_ for clusters with M_vir_ = 10^15^h^1^M_{sun}_, which
is inconsistent at 4{sigma} significance with the values of c_vir_ ~ 10
reported for stronglensingselected clusters. We have found that the
measurement error on the cluster mass is smaller at higher overdensities,
{DELTA} ~= 5002000, than at the virial overdensity, {DELTA}_vir_ ~= 110;
typical fractional errors at {DELTA} ~= 5002000 are improved to
{sigma}(M_{DELTA}_)/M_{DELTA}_ ~= 0.10.2 compared with 0.20.3 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}_) ~= 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 clusterscale halos
along the lineofsight.
Key words: cosmology: observations, dark matter, galaxies: clusters,
gravitational lensing
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