Traces of Anisotropic Quasi-Regular Structure in the SDSS Data

TL;DR

This study investigates large-scale anisotropic quasi-regular structures in SDSS galaxy data, identifying signs of a characteristic scale around 116 Mpc/h through power spectrum analysis and directional examination.

Contribution

It introduces a novel method of detecting anisotropic quasi-periodic structures in galaxy distributions using sector-based power spectra and directional analysis, revealing a potential large-scale regularity.

Findings

Detected anisotropic quasi-periodic structures at z < 0.5.

Identified a characteristic scale of approximately 116 Mpc/h.

Confirmed findings with SDSS DR12 data.

Abstract

The aim of this study is to search for quasi-periodical structures at moderate cosmological redshifts $z \la 0.5 $. We mainly use the SDSS DR7 data on the luminous red galaxies (LRGs) with redshifts $0.16 \leq z \leq 0.47$. At first, we analyze features (peaks) in the power spectra of radial (shell-like) distributions using separate angular sectors in the sky and calculate the power spectra within each sector. As a result, we found some signs of a large-scale anisotropic quasi-periodic structure detectable through 6 sectors out of a total of 144 sectors. These sectors are distinguished by large amplitudes of dominant peaks in their radial power spectra at wavenumbers $k$ within a narrow interval of $0.05 < k < 0.07$~h~Mpc$^{-1}$. Then, passing from a spherical coordinate system to a Cartesian one, we found a special direction such that the total distribution of LRG projections on it contains a significant ($\ga$5$\sigma$) quasi-periodical component. We assume that we are dealing with a signature of a quasi-regular structure with a characteristic scale $116 \pm 10$~h$^{-1}$~Mpc. Our assumption is confirmed by a preliminary analysis of the SDSS DR12 data.