Observational evidence of fractality in the large-scale distribution of galaxies

Abstract

Using a sample of 133 991 galaxies distributed in the sky region $100^{\circ }<\alpha <270^{\circ }$ and $7^{\circ }<\delta <65^{\circ }$, extracted from the SDSS NASA/AMES Value Added Galaxy Catalog (AMES-VAGC), we estimate the fractal dimension using two different methods. First, using an algorithm to estimate the correlation dimension. The second method, in a novel approach, creates a graph from the data and estimates the graph dimension purely from connectivity information. In both methods we found a dimension $D\approx 2$ in scales below 20 Mpc, which agrees with previous works. This result shows the non-homogeneity of galaxies distribution at certain scales.