Constraining the Scatter in the Mass-Richness Relation of maxBCG Clusters With Weak Lensing and X-ray Data

Journal Article · Mon Aug 03 04:00:00 EDT 2009 · Astrophys.J.699:768-781,2009

DOI:https://doi.org/10.1088/0004-637X/699/1/768· OSTI ID:962092

Rozo, Eduardo; Rykoff, Eli S; Evrard, August; Becker, Matthew R; McKay, Timothy; Wechsler, Risa H; Koester, Benjamin P; Hao, Jiangang; Hansen, Sarah; Sheldon, Erin; Johnston, David; Annis, James T; Frieman, Joshua A

We measure the logarithmic scatter in mass at fixed richness for clusters in the maxBCG cluster catalog, an optically selected cluster sample drawn from SDSS imaging data. Our measurement is achieved by demanding consistency between available weak lensing and X-ray measurements of the maxBCG clusters, and the X-ray luminosity-mass relation inferred from the 400d X-ray cluster survey, a flux limited X-ray cluster survey. We find {sigma}{sub lnM|N{sub 200}} = 0.45{sub -0.18}{sup +0.20} (95%CL) at N{sub 200} {approx} 40, where N{sub 200} is the number of red sequence galaxies in a cluster. As a byproduct of our analysis, we also obtain a constraint on the correlation coefficient between lnL{sub X} and lnM at fixed richness, which is best expressed as a lower limit, r{sub L,M|N} {ge} 0.85 (95% CL). This is the first observational constraint placed on a correlation coefficient involving two different cluster mass tracers. We use our results to produce a state of the art estimate of the halo mass function at z = 0.23 - the median redshift of the maxBCG cluster sample - and find that it is consistent with the WMAP5 cosmology. Both the mass function data and its covariance matrix are presented.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 962092
• Report Number(s): SLAC-PUB-13730; arXiv:0809.2794
• Journal Information: Astrophys.J.699:768-781,2009, Journal Name: Astrophys.J.699:768-781,2009
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASTROPHYSICS
Astrophysics
COSMOLOGY
GALAXIES
GALAXY CLUSTERS
LUMINOSITY
MASS
SCATTERING