Note on redshift distortion in Fourier space

	Note on redshift distortion in Fourier space
	Cai, Yan-Chuan ; Pan, Jun
刊名	CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS
	2007
卷号	7 期号:1 页码:51-62
关键词	cosmology : theory large-scale structure of universe methods : statistical
英文摘要	We explore features of redshift distortion in Fourier analysis of N-body simulations. The phases of the Fourier modes of dark matter density fluctuation are generally shifted by the peculiar motion along the line of sight, the induced phase shift is stochastic and has a probability distribution function (PDF) that is symmetric about the peak at zero shift and whose exact shape depends on the wave vector, except on very large scales where phases are invariant by linear perturbation theory. Analysis of the phase shifts motivates our phenomenological models for the bispectrum in redshift space. Comparison with simulations shows that our toy models are very successful in modeling bispectrum of equilateral and isosceles triangle,; at large scales. In the second part we compare the monopole of the power spectrum and bispectrum in the radial and plane-parallel distortion to test the plane-parallel approximation. We confirm the results of Scoccimarro that difference of power spectrum is at the level of 10%, and, in the reduced bispectrum, the difference is as small as a few percent. However, on the plane perpendicular to the line of sight of k(z) = 0, the difference in power spectrum between the radial and plane-parallel approximation can be more than similar to 10%, and even worse on very small scales. Such difference is prominent for bispectrum, especially for configurations of tilted triangles. Non-Gaussian signals under the radial distortion on small scales are systematically biased downside than are in the plane-parallel approximation, with amplitudes depending on the opening angle of the sample point to the observer. This observation gives warning to the practice of using the power spectrum and bispectrum measured on the k(z) = 0 plane as estimates of the real space statistics.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	PHASE CORRELATIONS ; POWER SPECTRUM ; REAL-SPACE ; DENSITY ; BISPECTRUM ; FIELDS ; FLUCTUATIONS ; SIGNATURE ; EVOLUTION ; GALAXIES
收录类别	SCI
语种	英语
WOS记录号	WOS:000244675200002
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/15872]
专题	紫金山天文台_南极天文中心
作者单位	1.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China 2.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
推荐引用方式 GB/T 7714	Cai, Yan-Chuan,Pan, Jun. Note on redshift distortion in Fourier space[J]. CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS,2007,7(1):51-62.
APA	Cai, Yan-Chuan,&Pan, Jun.(2007).Note on redshift distortion in Fourier space.CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS,7(1),51-62.
MLA	Cai, Yan-Chuan,et al."Note on redshift distortion in Fourier space".CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS 7.1(2007):51-62.