BAO angular scale at z_eff = 0.11 with the SDSS blue galaxies

TL;DR

This study detects the transverse BAO signal at low redshift using SDSS blue galaxies, providing a new measurement of the angular diameter distance and constraining cosmological models with minimal model dependence.

Contribution

It presents a novel weakly model-dependent method to measure the transverse BAO signal in thin redshift slices using SDSS blue galaxies, and derives cosmological parameters from these measurements.

Findings

Detected BAO signal at 2.2 sigma significance

Measured angular diameter distance at z=0.11 as 258.31 ± 13.71 Mpc/h

Combined low-redshift BAO data with literature to constrain ΛCDM models

Abstract

We measure the transverse baryon acoustic oscillations (BAO) signal in the local Universe using a sample of blue galaxies from the Sloan Digital Sky Survey (SDSS) survey as a cosmological tracer. The method is weakly dependent on a cosmological model and is suitable for 2D analyses in thin redshift bins to investigate the SDSS data in the interval $z {\in} [0.105, 0.115]$. We detect the transverse BAO signal ${\theta}_{BAO} = 19.8^{\deg} {\pm} 1.05^{\deg}$ at $z_{eff} = 0.11$, with a statistical significance of $2.2 {\sigma}$. Additionally, we perform tests that confirm the robustness of this angular BAO signature. Supported by a large set of log-normal simulations, our error analyses include statistical and systematic contributions. In addition, considering the sound horizon scale calculated by the Planck Collaboration, $r_{s}^{Planck}$, and the ${\theta}_{BAO}$ value obtained here, we obtain a measurement of the angular diameter distance $D_{A}(0.11) = 258.31 {\pm} 13.71 \,Mpc/h$. Moreover, combining this ${\theta}_{BAO}$ measurement at low redshift with other BAO angular scale data reported in the literature, we perform statistical analyses for the cosmological parameters of some Lambda cold dark matter (${\Lambda}$CDM) type models.