Open AccessRedshift distortions in one‐dimensional power spectra
Author(s) -
Desjacques Vincent,
Nusser Adi
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07879.x
Subject(s) - physics , redshift , spectral density , astrophysics , matter power spectrum , spectral line , redshift space distortions , redshift survey , quasar , amplitude , sky , galaxy , astronomy , optics , statistics , mathematics
We present a model for one‐dimensional (1D) matter power spectra in redshift space as estimated from data provided along individual lines of sight. We derive analytic expressions for these power spectra in the linear and non‐linear regimes, focusing on redshift distortions arising from peculiar velocities. In the linear regime, redshift distortions enhance the 1D power spectra only on small scales and do not affect the power on large scales. This is in contrast to the effect of distortions on three‐dimensional (3D) power spectra estimated from data in 3D space, where the enhancement is independent of scale. For cold dark matter (CDM) cosmologies, the 1D power spectra in redshift and real space are similar for wavenumbers q ≲ 0.1 h Mpc −1 where both have a spectral index close to unity, independent of the details of the 3D power spectrum. Non‐linear corrections drive the 1D power spectrum in redshift space into a nearly universal shape over scales q ≲ 10 h Mpc −1 , and suppress the power on small scales as a result of the strong velocity shear and random motions. The redshift‐space 1D power spectrum is mostly sensitive to the amplitude of the initial density perturbations. Our results are useful in particular for power spectra computed from the Sloan Digital Sky Survey (SDSS) quasars sample.