Measuring the 2D Baryon Acoustic Oscillation signal of galaxies in WiggleZ: Cosmological constraints

TL;DR

This paper analyzes the 2D anisotropic BAO signal in WiggleZ galaxy data to derive cosmological parameters, using full shape and peak position methods, and confirms results are unbiased and consistent with standard cosmology.

Contribution

It introduces a comprehensive analysis of the 2D BAO signal in WiggleZ data, employing both full shape and peak position methods, with improved covariance and validation with mock data.

Findings

Constraints on $ ext{Ω}_c h^2$, $H(z)$, and $D_A(z)$ with 5-22% errors.

Results are consistent with Flat ΛCDM cosmology.

Agreement with BOSS survey results.

Abstract

We present results from the 2D anisotropic Baryon Acoustic Oscillation (BAO) signal present in the final dataset from the WiggleZ Dark Energy Survey. We analyse the WiggleZ data in two ways: firstly using the full shape of the 2D correlation function and secondly focussing only on the position of the BAO peak in the reconstructed data set. When fitting for the full shape of the 2D correlation function we use a multipole expansion to compare with theory. When we use the reconstructed data we marginalise over the shape and just measure the position of the BAO peak, analysing the data in wedges separating the signal along the line of sight from that parallel to the line of sight. We verify our method with mock data and find the results to be free of bias or systematic offsets. We also redo the pre-reconstruction angle averaged (1D) WiggleZ BAO analysis with an improved covariance and present an updated result. The final results are presented in the form of $\Omega_c h^2$, $H(z)$, and $D_A(z)$ for three redshift bins with effective redshifts $z = 0.44$, $0.60$, and $0.73$. Within these bins and methodologies, we recover constraints between 5% and 22% error. Our cosmological constraints are consistent with Flat $\Lambda$CDM cosmology and agree with results from the Baryon Oscillation Spectroscopic Survey (BOSS).