Fitting Methods for Baryon Acoustic Oscillations in the Lyman-{\alpha} Forest Fluctuations in BOSS Data Release 9

TL;DR

This paper introduces advanced fitting methods for analyzing BAO features in the Lyman-alpha forest fluctuations, applied to BOSS DR9 data, enabling precise cosmological measurements with publicly available software.

Contribution

We developed a comprehensive fitting approach that accounts for distortions and anisotropies, allowing independent BAO scale measurements and providing tools for reproducible analysis.

Findings

Successful application to BOSS DR9 data

Separate measurements of BAO angular and velocity scales

Public release of software and input files

Abstract

We describe fitting methods developed to analyze fluctuations in the Lyman-{\alpha} forest and measure the parameters of baryon acoustic oscillations (BAO). We apply our methods to BOSS Data Release 9. Our method is based on models of the three-dimensional correlation function in physical coordinate space, and includes the effects of redshift-space distortions, anisotropic non-linear broadening, and broadband distortions. We allow for independent scale factors along and perpendicular to the line of sight to minimize the dependence on our assumed fiducial cosmology and to obtain separate measurements of the BAO angular and relative velocity scales. Our fitting software and the input files needed to reproduce our main BOSS Data Release 9 results are publicly available.