For refcode 2010ApJ...721..875O: Retrieve 12 NED objects in this reference. Please click here for ADS abstract
NED Abstract
Copyright by American Astronomical Society.
Reproduced by permission
2010ApJ...721..875O
LoCuSS: Calibrating Massobservable Scaling Relations for Cluster Cosmology
with Subaru Weaklensing Observations
Okabe, N.; Zhang, Y.Y.; Finoguenov, A.; Takada, M.; Smith, G. P.; Umetsu,
K.; Futamase, T.
Abstract. We present a joint weaklensing/Xray study of galaxy cluster
massobservable scaling relations motivated by the critical importance of
accurate calibration of mass proxies for future Xray missions, including
eROSITA. We use a sample of 12 clusters at z ~= 0.2 that we have observed
with Subaru and XMMNewton to construct relationships between the
weaklensing mass (M) and three Xray observables, gas temperature (T),
gas mass (M_gas_), and quasiintegrated gas pressure (Y_X_), at
overdensities of {DELTA} = 2500, 1000, and 500 with respect to the
critical density. We find that M_gas_ at {DELTA} <= 1000 appears to be the
most promising mass proxy of the three because it has the lowest intrinsic
scatter in mass at a fixed observable, {sigma}_ln M_ ~= 0.1, independent
of the cluster dynamical state. The scatter in mass at fixed T and Y_X_ is
a factor of ~23 larger than at fixed M_gas_, which are indicative of the
structural segregation that we find in the MT and MY_X_ relationships.
Undisturbed clusters are found to be ~40% and ~20% more massive than
disturbed clusters at fixed T and Y_X_, respectively, at ~2{sigma}
significance. In particular, A 1914a wellknown merging
clustersignificantly increases the scatter and lowers the normalization
of the relation for disturbed clusters. We also investigated the
covariance between the intrinsic scatter in MM_gas_ and MT relations,
finding that they are positively correlated. This contradicts the adaptive
mesh refinement simulations that motivated the idea that Y_X_ may be a
lowscatter mass proxy, and agrees with more recent smoothed particle
hydrodynamic simulations based on the Millennium Simulation. We also
propose a method to identify a robust mass proxy based on principal
component analysis. The statistical precision of our results is limited by
the small sample size and the presence of the extreme merging cluster in
our sample. We therefore look forward to studying a larger, more complete
sample in the future.
Key words: cosmology: observations, dark matter, galaxies: clusters:
general, gravitational lensing: weak, Xrays: galaxies: clusters
Retrieve 12 NED objects in this reference. Please click here for ADS abstract
