TITLE:
Improved optical mass tracer for galaxy clusters calibrated using weak lensing measurements.
AUTHOR(S):
R. Reyes, R. Mandelbaum, C. Hirata, N. Bahcall, U. Seljak.
DATE:
2008 Feb 17 (MNRAS, submitted); 2008 Feb 17 (arXiv, v1, posted);
2008 Aug 11 (revised);
2008 Aug 11 (MNRAS, accepted);
2008 Aug 16 (arXiv, v2, posted);
2008 Oct 03 (MNRAS, published).
AVAILABILITY:
arXiv 0802.2365 (free);
Wiley (requires subscription).
PUBLICATION INFORMATION:
Mon. Not. R. Astron. Soc., 390, 1157--1169.
ABSTRACT:
We develop an improved mass tracer for clusters of galaxies from optically observed parameters, and calibrate the mass relation using weak
gravitational lensing measurements. We employ a sample of ~ 13,000 optically-selected clusters from the Sloan Digital Sky Survey (SDSS) maxBCG catalog,
with photometric redshifts in the range 0.1-0.3. The optical tracers we consider are cluster richness, cluster luminosity, luminosity of the brightest
cluster galaxy (BCG), and combinations of these parameters. We measure the weak lensing signal around stacked clusters as a function of the different
tracers, and use it to determine the tracer with the least amount of scatter. We further use the weak lensing data to calibrate the mass normalization.
We find that the best mass estimator for massive clusters is a combination of cluster richness, N_{200}, and the luminosity of the brightest cluster
galaxy, L_{BCG}: M_{200\bar{\rho}} = (1.27 +/- 0.08) (N_{200}/20)^{1.20 +/- 0.09} (L_{BCG}/\bar{L}_{BCG}(N_{200}))^{0.71 +/- 0.14} \times 10^{14}
h^{-1} M_sun, where $\bar{L}_{BCG}(N_{200})$ is the observed mean BCG luminosity at a given richness. This improved mass tracer will enable the use of
galaxy clusters as a more powerful tool for constraining cosmological parameters.
ADS BIBLIOGRAPHIC CODE: 2008MNRAS.390.1157R
COMMENTS: SDSS Publication #859.