An improved measurement of baryon acoustic oscillations from the correlation function of galaxy clusters at z 0.3

We detect the peak of baryon acoustic oscillations (BAO) in the two-point correlation function of a spectroscopic sample of 25 226 clusters selected from the Sloan Digital Sky Survey. Galaxy clusters, as tracers of massive dark matter haloes, are highly biased structures. The linear bias b of the sample considered in this work, that we estimate from the projected correlation function, is b σ 8 = 1.72 ± 0.03. Thanks to the high signal in the cluster correlation function and to the accurate spectroscopic redshift measurements, we can clearly detect the BAO peak and determine its position, sp, with high accuracy, despite the relative paucity of the sample. Our measurement, sp = 104 ± 7 Mpc h−1 , is in good agreement with previous estimates from large galaxy surveys, and has a similar uncertainty. The BAO measurement presented in this work thus provides a new strong confirmation of the concordance cosmological model and demonstrates the power and promise of galaxy clusters as key probes for cosmological applications based on large-scale structures.