Synthesizing the Observed Distribution of Galaxies
Abstract
We develop a technique, based on the galaxy distribution function, to synthesize the observed distribution of galaxies. It populates space with a Poisson distribution of cluster centers and places particles around each center according to a specific prescription. We specify each cluster, assumed to be spherical, by three quantities: the number of particles in the cluster, its radius, and its radial density profile. The observed galaxy distribution function and its scale dependence gives the probability that a cluster has N associated particles and also constrains the distribution of cluster radii and the radial density profiles. ] In our most successful models, identical particles are arranged in Poisson distributed spherical clusters that do not overlap, the radial density profile of any cluster resembles an isothermal sphere, and the probability that a cluster has N associated particles is given by the observed gravitational quasiequilibrium distribution function. Various statistical analyses (twopoint correlation function, countsincells distribution functions, percolation) all show that this model is remarkably similar to the observed distribution of galaxies. This technique also illustrates the constraints that galaxy distribution functions place on models of largescale structure. All these models should be tested against the observed galaxy distribution function over a wide range of scales.
 Publication:

The Astrophysical Journal
 Pub Date:
 December 1994
 DOI:
 10.1086/174973
 Bibcode:
 1994ApJ...437...35S
 Keywords:

 Astronomical Models;
 Density Distribution;
 Distribution Functions;
 Galactic Clusters;
 Poisson Density Functions;
 Statistical Correlation;
 Universe;
 Mathematical Models;
 Statistical Distributions;
 Astrophysics;
 GALAXIES: CLUSTERING;
 METHODS: NUMERICAL;
 COSMOLOGY: LARGESCALE STRUCTURE OF UNIVERSE