UC Berkeley

We present distance scale measurements from the baryon acoustic oscillation signal in the constant stellar mass and low-redshift sample samples from the Data Release 12 of the Baryon Oscillation Spectroscopic Survey. The total volume probed is 14.5 Gpc3, a 10 per cent increment from Data Release 11. From an analysis of the spherically averaged correlation function, we infer a distance to z = 0.57 of DV (z)rdfid /rd = 2028 ± 21 Mpc and a distance to z = 0.32 of DV (z)rdfid /rd = 1264 ± 22 Mpc assuming a cosmology in which rdfid = 147.10 Mpc. From the anisotropic analysis, we find an angular diameter distance to z = 0.57 of DA(z)rdfid /rd = 1401 ± 21 Mpc and a distance to z = 0.32 of 981 ± 20 Mpc, a 1.5 and 2.0 per cent measurement, respectively. The Hubble parameter at z = 0.57 is H(z)rd/rdfid = 100.3 ± 3.7kms-1 Mpc-1 and its value at z=0.32 is 79.2±5.6 kms-1 Mpc-1, a 3.7 and 7.1 per cent measurement, respectively. These cosmic distance scale constraints are in excellent agreement with aΛcold dark matter model with cosmological parameters released by the recent Planck 2015 results.