Application of Data Compression Methods to the Redshift-space distortions of the PSCz galaxy catalogue

TL;DR

This paper applies advanced spherical harmonic analysis and data compression techniques to the PSCz galaxy survey to accurately measure redshift distortions, galaxy clustering, and infer cosmological parameters.

Contribution

It introduces new parameter eigenvector and hierarchical data compression methods enabling analysis of more harmonic modes with reduced errors.

Findings

Measured redshift-space distortion parameter β = 0.39 ± 0.12

Determined galaxy clustering amplitude Δ_gal(0.1) = 0.42 ± 0.02

Estimated cosmological matter density Ω_m = 0.16 ± 0.03

Abstract

We apply a spherical harmonic analysis to the Point Source Redshift Survey (PSCz), to compute the real-space galaxy power spectrum and the degree of redshift distortion caused by peculiar velocities. We employ new parameter eigenvector and hierarchical data compression techniques, allowing a much larger number of harmonic modes to be included, and correspondingly smaller error bars. Using 4644 harmonic modes, compressed to 2278, we find that the IRAS redshift-space distortion parameter is $\beta = 0.39 \pm 0.12$ and the amplitude of galaxy clustering on a scale of $k=0.1 \Mpch$ is $\Delta_{\rm gal}(0.1)=0.42 \pm 0.02$. Combining these we find the amplitude of mass perturbations is $\Delta_m(0.1)=(0.16\pm0.04) \Omega_m^{-0.6}$. A preliminary model fitting analysis combining the PSCz amplitudes with the CMB and abundance of clusters yields the cosmological matter density parameter $\Omega_m=0.16\pm 0.03$, the amplitude of primordial perturbations $Q=(8.4\pm 3.8) \times 10^{-5}$, and the IRAS bias parameter $b=0.84\pm 0.28$.