Nonselfsimilar clustering of galaxies
Abstract
The evolution of an initially Gaussian field in two dimensional n body simulations is examined, in order to detect how the large scale density fluctuations influence the development of small scale clustering. The power spectra of the initial density fluctuations are assumed to have a power law form P(k) proportional to k^{n} with n = 1 and a different cutoff on large scales. The numerical results show that the evolution of small scale structures is not self similar, but strongly depends on the long wavelength cutoff scale. The scale in which density fluctuations go nonlinear is determined by the value square root of (lambda_{l} x lambda_{delta}), where lambda_{l} is the cutoff scale in the power spectrum, and lambda _{delta} is the length scale in which the mean square amplitude of the density fluctuations becomes equal to unity. The variance of the power spectrum and potential field in different subsamples and its dependence on lambda_{l} is analyzed. To investigate the gravitational potential field from observational data, the sample size must be at least of the order of the cutoff scale in the power spectrum. To determine the break of the spectrum of galaxy clustering, the size of the sample must be two times larger than this scale.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 November 1991
 Bibcode:
 1991STIN...9311338G
 Keywords:

 Galactic Clusters;
 Galactic Evolution;
 Power Spectra;
 Spectrum Analysis;
 Amplitudes;
 Gravitational Fields;
 Nonlinearity;
 Potential Fields;
 Two Dimensional Models;
 Astrophysics