The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: anisotropic galaxy clustering in Fourier space

We investigate the anisotropic clustering of the Baryon OscillationSpectroscopic Survey (BOSS) Data Release 12 sample, which consists of1198 006 galaxies in the redshift range 0.2 z 0.75 and a skycoverage of 10 252 deg². We analyse this data set in Fourierspace, using the power-spectrum multipoles to measure redshift-spacedistortions simultaneously with the Alcock-Paczynski effect and thebaryon acoustic oscillation scale. We include the power-spectrummonopole, quadrupole and hexadecapole in our analysis and compare ourmeasurements with a perturbation-theory-based model, while properlyaccounting for the survey window function. To evaluate the reliabilityof our analysis pipeline, we participate in a mock challenge, whichresults in systematic uncertainties significantly smaller than thestatistical uncertainties. While the high-redshift constraint onfσ₈ at z_eff = 0.61 indicates a small(˜1.4σ) deviation from the prediction of the PlanckΛCDM (Λ cold dark matter) model, the low-redshiftconstraint is in good agreement with Planck ΛCDM. This paper ispart of a set that analyses the final galaxy clustering data set fromBOSS. The measurements and likelihoods presented here are combined withothers in Alam et al. to produce the final cosmological constraints fromBOSS.