Cosmological Constraints From SDSS MaxBCG Cluster Abundances

Journal Article · Mon Mar 26 04:00:00 EDT 2007 · Submitted to Astrophys.J.

OSTI ID:901581

Rozo, Eduardo; Wechsler, Risa H; Koester, Benjamin P; McKay, Timothy A; Evrard, August E; Johnston, David; Sheldon, Erin S; Annis, James; Frieman, Joshua A

We perform a maximum likelihood analysis of the cluster abundance measured in the SDSS using the maxBCG cluster finding algorithm. Our analysis is aimed at constraining the power spectrum normalization {sigma}{sub 8}, and assumes flat cosmologies with a scale invariant spectrum, massless neutrinos, and CMB and supernova priors {Omega}{sub m}h{sup 2} = 0.128 {+-} 0.01 and h = 0.72 {+-} 0.05 respectively. Following the method described in the companion paper Rozo et al. (2007), we derive {sigma}{sub 8} = 0.92 {+-} 0.10 (1{sigma}) after marginalizing over all major systematic uncertainties. We place strong lower limits on the normalization, {sigma}{sub 8} > 0.76 (95% CL) (> 0.68 at 99% CL). We also find that our analysis favors relatively low values for the slope of the Halo Occupation Distribution (HOD), {alpha} = 0.83 {+-} 0.06. The uncertainties of these determinations will substantially improve upon completion of an ongoing campaign to estimate dynamical, weak lensing, and X-ray cluster masses in the SDSS maxBCG cluster sample.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 901581
• Report Number(s): SLAC-PUB-12415; astro-ph/0703571
• Journal Information: Submitted to Astrophys.J., Journal Name: Submitted to Astrophys.J.
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ABUNDANCE
Astrophysics
ASTRO
DISTRIBUTION
NEUTRINOS
OCCUPATIONS