Measuring the distance-redshift relation with the baryon acoustic oscillations of galaxy clusters


Abstract in English

We analyse the largest spectroscopic samples of galaxy clusters to date, and provide observational constraints on the distance-redshift relation from baryon acoustic oscillations. The cluster samples considered in this work have been extracted from the Sloan Digital Sky Survey at three median redshifts, $z=0.2$, $z=0.3$, and $z=0.5$. The number of objects is $12910$, $42215$, and $11816$, respectively. We detect the peak of baryon acoustic oscillations for all the three samples. The derived distance constraints are: $r_s/D_V(z=0.2)=0.18 pm 0.01$, $r_s/D_V(z=0.3)=0.124 pm 0.004$ and $r_s/D_V(z=0.5)=0.080 pm 0.002$. Combining these measurements, we obtain robust constraints on cosmological parameters. Our results are in agreement with the standard $Lambda$ cold dark matter model. Specifically, we constrain the Hubble constant in a $Lambda$CDM model, $H_0 = 64_{-9}^{+14} , mathrm{km} , mathrm{s}^{-1}mathrm{Mpc}^{-1}$, the density of curvature energy, in the $oLambda$CDM context, $Omega_K = -0.015_{-0.36}^{+0.34}$, and finally the parameter of the dark energy equation of state in the $ow$CDM case, $w = -1.01_{-0.44}^{+0.44}$. This is the first time the distance-redshift relation has been constrained using only the peak of baryon acoustic oscillations of galaxy clusters.

Download