Power spectrum of the maxBCG sample: detection of acoustic oscillations
  using galaxy clusters
  We use the direct Fourier method to calculate the redshift-space power
spectrum of the maxBCG cluster catalog -- currently by far the largest existing
galaxy cluster sample. The total number of clusters used in our analysis is
12,616. After accounting for the radial smearing effect caused by photometric
redshift errors and also introducing a simple treatment for the nonlinear
effects, we show that currently favored low matter density "concordance" LCDM
cosmology provides a very good fit to the estimated power. Thanks to the large
volume (~0.4 h^{-3}Gpc^{3}), high clustering amplitude (linear effective bias
parameter b_{eff} ~3x(0.85/sigma_8)), and sufficiently high sampling density
(~3x10^{-5} h^{3}Mpc^{-3}) the recovered power spectrum has high enough signal
to noise to allow us to find evidence (~2 sigma CL) for the baryonic acoustic
oscillations (BAO). In case the clusters are additionally weighted by their
richness the resulting power spectrum has slightly higher large-scale amplitude
and smaller damping on small scales. As a result the confidence level for the
BAO detection is somewhat increased: ~2.5 sigma. The ability to detect BAO with
relatively small number of clusters is encouraging in the light of several
proposed large cluster surveys.
