Fourier analysis of redshift space distortions and the determination of Omega
Aug, 1993
27 pages
Published in:
- Mon.Not.Roy.Astron.Soc. 267 (1994) 785
e-Print:
- astro-ph/9308003 [astro-ph]
Report number:
- IASSNS-AST-93-49
View in:
Citations per year
Abstract: (arXiv)
The peculiar velocities of galaxies distort the pattern of galaxy clustering in redshift space, making the redshift space power spectrum anisotropic. In the linear regime, the strength of this distortion depends only on the ratio , where is the cosmological density parameter and is the bias parameter. We derive a linear theory estimator for based on the harmonic moments of the redshift space power spectrum. Using N-body simulations, we examine the impact of non-linear gravitational clustering on the power spectrum anisotropy and on our -estimator. Non-linear effects can be important out to wavelengths Mpc/h or larger: in most cases, they lower the quadrupole moment of the power spectrum and thereby depress the estimate of below the true value. With a sufficiently large redshift survey, the scaling of non-linear effects may allow separate determinations of and . We describe a practical technique for measuring the anisotropy of the power spectrum from galaxy redshift surveys, and we test the technique on mock catalogues drawn from the N-body simulations. Preliminary application of our methods to the 1.2 Jy IRAS galaxy survey yields at wavelengths Mpc/h . Non-linear effects remain important at these scales, so this estimate of is probably lower than the true value.References(34)
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