Variance, Skewness & Kurtosis: results from the APM Cluster Redshift Survey and model predictions

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

12 pages PostScript, 12 figures

Scientific paper

We estimate the variance $\xibar_2$, the skewness $\xibar_3$ and the kurtosis $\xibar_4$ in the distribution of density fluctuations in a complete sample from the APM Cluster Redshift Survey with 339 clusters and a mean depth $ \sim 250\Mpc$. We are able to measure the statistics of fluctuations in spheres of radius $R \simeq 5-80 \Mpc$, with reasonable errorbars. The statistics in the cluster distribution follow the hierarchical pattern $\xibar_J=S_J~\xibar_2^{J-1}$ with $S_J$ roughly constant, $S_3 \simeq 2$ and $S_4 \sim 8$. We analyse the distribution of clusters taken from N-body simulations of different dark matter models. The results are compared with an alternative method of simulating clusters which uses the truncated Zel'dovich approximation. We argue that this alternative method is not reliable enough for making quantitative predictions of $\xibar$. The N-body simulation results follow similar hierarchical relations to the observations, with $S_J$ almost unaffected by redshift distortions from peculiar motions. The standard $\Omega=1$ Cold Dark Matter (CDM) model is inconsistent with either the second, third or fourth order statistics at all scales. However both a hybrid Mixed Dark Matter model and a low density CDM variant agree with the $\xibar_J$ observations.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Variance, Skewness & Kurtosis: results from the APM Cluster Redshift Survey and model predictions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Variance, Skewness & Kurtosis: results from the APM Cluster Redshift Survey and model predictions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variance, Skewness & Kurtosis: results from the APM Cluster Redshift Survey and model predictions will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-433671

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.