1 research outputs found
CMB anisotropy from spatial correlations of clusters of galaxies
The SZ effect from clusters of galaxies is a dominant source of secondary CMB
anisotropy in the low-redshift universe. We present analytic predictions for
the CMB power spectrum from massive halos arising from the SZ effect. Since
halos are discrete, the power spectrum consists of a Poisson and a correlation
term. The latter is always smaller than the former, which is dominated by
nearby bright rich clusters. In practice however, those bright clusters are
easy to indentify and can thus be subtracted from the map. After this
subtraction, the correlation term dominates degree-scale fluctuations over the
Poisson term, as the main contribution to the correlation term comes from
distant clusters. We find that the correlation term is detectable by Planck
experiment. Since the degree scale spectrum is quite insensitive to the highly
uncertain core structures of halos, our predictions are robust on these scales.
Measuring the correlation term on degree scales thus cleanly probes the
clustering of distant halos. This has not been measured yet, mainly because
optical and X-ray surveys are not sufficiently sensitive to include such
distant clusters and groups. Our analytic predictions are also compared to
adiabatic hydrodynamic simulations. The agreement is remarkably good, down to
ten arcminutes scales, indicating that our predictions are robust for the
Planck experiment. Below ten arcminute scales, where the details of the core
structure dominates the power spectrum, our analytic and simulated predictions
might fail. In the near future, interferometer and bolometer array experiments
will measure the SZ power spectrum down to arcminutes scales, and yield new
insight into the physics of the intrahalo medium.Comment: 9 pages, 4 figures. submitted to Proceedings of the 9th Marcel
Grossmann meetin