Quasi-periodical components in the radial distributions of cosmologically remote objects

Abstract

A statistical analysis of radial (line-of-sight) 1D-distributions of brightest cluster galaxies (BCGs) within the redshift interval $0.044 \leq z \leq 0.78$ and Mg II absorption-line systems ($0.37 \leq z \leq 2.28$) is carried out. Power spectra and two-point radial correlation functions are calculated. It is found that both radial distributions of spectroscopic redshifts of 52,683 BCGs and 32,840 Mg II absorption systems incorporate similar quasi-periodical components relatively to the comoving distance. Significance of the components exceeds $4\sigma$-level and admits an increase ($\geq 5\sigma$) for some broad subsamples. For the {\Lambda}CDM cosmological model the periodicities correspond to spatial comoving scales ($98 \pm 3$) and ($101 \pm 2$)h$^{-1}$ Mpc, respectively. These quasi-periods turn out to be close to the characteristic scale ($101 \pm 6$)h$^{-1}$Mpc of the quasi-periodical component obtained earlier for the radial distribution of luminous red galaxies (LRGs). On the other hand, the scales are close to the spatial scale corresponding to the baryon acoustic oscillations (BAOs) revealed by many authors at the last decade. Fourier transform phases obtained for the BCGs and LRGs are found to be close, while the phases calculated for the Mg II absorption systems and LRGs are opposite. Discussions of the results in a context of the BAO and large-scale structure characteristic scales are outlined.