Measuring the Mean and Scatter of the X-ray Luminosity -- Optical Richness Relation for maxBCG Galaxy Clusters

Journal Article · Tue Oct 02 04:00:00 EDT 2007 · Submitted to ApJ

DOI:https://doi.org/10.1086/520329· OSTI ID:917268

Rykoff, E S; McKay, T A; Becker, M A; Evrard, A; Johnston, D E; Koester, B P; Rozo, E; Sheldon, E S; Wechsler, Risa H

We interpret and model the statistical weak lensing measurements around 130,000 groups and clusters of galaxies in the Sloan Digital Sky Survey presented by Sheldon et al. (2007). We present non-parametric inversions of the 2D shear profiles to the mean 3D cluster density and mass profiles in bins of both optical richness and cluster i-band luminosity. Since the mean cluster density profile is proportional to the cluster-mass correlation function, the mean profile is spherically symmetric by the assumptions of large-scale homogeneity and isotropy. We correct the inferred 3D profiles for systematic effects, including non-linear shear and the fact that cluster halos are not all precisely centered on their brightest galaxies. We also model the measured cluster shear profile as a sum of contributions from the brightest central galaxy, the cluster dark matter halo, and neighboring halos. We infer the relations between mean cluster virial mass and optical richness and luminosity over two orders of magnitude in cluster mass; the virial mass at fixed richness or luminosity is determined with a precision of {approx} 13% including both statistical and systematic errors. We also constrain the halo concentration parameter and halo bias as a function of cluster mass; both are in good agreement with predictions from N-body simulations of LCDM models. The methods employed here will be applicable to deeper, wide-area optical surveys that aim to constrain the nature of the dark energy, such as the Dark Energy Survey, the Large Synoptic Survey Telescope and space-based surveys.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 917268
• Report Number(s): SLAC-PUB-12812; arXiv:0709.1158
• Journal Information: Submitted to ApJ, Journal Name: Submitted to ApJ; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCURACY
Astrophysics
ASTRO
CORRELATION FUNCTIONS
GALAXIES
GALAXY CLUSTERS
ISOTROPY
LUMINOSITY
NONLUMINOUS MATTER
SHEAR
SKY
TELESCOPES