Simposio Andino de Astrofísica Relativista

Study of multifractal structure of the galaxy distribution on a large scale from the SDSS DR7 considering spatial holes

Not scheduled

15m

Escuela de Física (Universidad Industrial de Santander, Bucaramanga Colombia)

Speaker

Ms Jorge García-Farieta (Universidad Nacional de Colombia)

Description

We have analyzed the spatial distribution of galaxies on a large-scale from the fractal point of view using the data release of the Sloan Digital Sky Survey of galactic redshifts (SDSS DR7) including observational holes. We build homogeneous catalogs following the radial selection function using the "shuffled" method with a main sample that contains 486078 galaxies. Additionally, a random distribution of observational holes in right ascension and declination was created in the mask of the SDSS DR7 catalog and we calculated the fractal dimension and lacunarity spectrum. Using the sliding-window technique, the multifractal spectrum and its dependence with the radial distance was determined. Some preliminary results of our analysis show that the clustering of galaxies exhibits fractal behaviour that depends on the radial distance, nevertheless a transition to homogeneity is not observed in the calculation of the fractal dimension; instead, the galaxy distribution is characterized as multifractal object whose dimensional spectrum does not exceed the physical spatial dimension for radial distances up to 180 Mpc/h within the main sample. These results and their physics implications are discussed in the context of the formation of large-scale structures in the Universe from the theoretical developments and recent fractal analysis of galaxy surveys based in the idea of a conditional cosmological principle.