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

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 ${\theta }_{BAO}=19.8^{°}\pm 1.05^{°}$ 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 $D_A(0.11)=258.31\pm 13.71Mpc/h$. 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.

7 pages, 7 figures