DWT power spectrum of the two-degree field galaxy redshift survey

	DWT power spectrum of the two-degree field galaxy redshift survey
	Cai, Yan-Chuan 1,2; Pan, Jun1 ; Zhao, Yong-Heng2 ; Feng, Long-Long 1; Fang, Li-Zhi 3
刊名	CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS
	2008-04-01
卷号	8 期号:2 页码:159-178
关键词	methods : data analysis methods : statistical (cosmology :) cosmological parameters (cosmology :) large-scale structure of universe
英文摘要	The power spectrum of the two-degree Field Galaxy Redshift Survey (2dFGRS) sample is estimated with the discrete wavelet transform (DWT) method. The DWT power spectra within 0.035 < k < 2.2 h Mpc(-1) are measured for three volume-limited samples defined in consecutive absolute magnitude bins -19 similar to -18, -20 similar to -19 and -21 similar to -20. We show that the DWT power spectrum can effectively distinguish Lambda CDM models of sigma(8) = 0.84 and sigma(8) = 0.74. We adopt maximum likelihood method to perform three-parameter fitting of the bias parameter b, pairwise velocity dispersion sigma(pv) and redshift distortion parameter beta = Omega(0.6)(m)/b to the measured DWT power spectrum. The fitting results state that in a sigma(8) = 0.84 universe the best-fit values of Omega(m) given by the three samples are mutually consistent within the range 0.28 similar to 0.36, and the best fitted values of sigma(pv) are 398(-27)(+35), 475(-29)(+37) and 550 +/- 20km s(-1) for the three samples, respectively. In the model of sigma(8) = 0.74, our three samples give very different values of Omega(m). We repeated the fitting using the empirical formula of redshift distortion. The result of the model of low sigma(8) is still poor, especially, one of the best-fit values of sigma(pv) is as large as 10(3) km s(-1). We also repeated our fitting by incorporating a scale-dependent galaxy bias. This gave a slightly lower value of Omega(m). Differences between the models of sigma(8) = 0.84 and sigma(8) = 0.74 still exist in the fitting results. The power spectrum of 2dFGRS seems to disfavor models with low amplitude of density fluctuations if the bias parameter is assumed to be scale independent. For the fitting value of Omega(m) to be consistent with that given by WMAP3, strong scale dependence of the bias parameters is needed.
收录类别	SCI
语种	英语
WOS记录号	WOS:000255262600004
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/7356]
专题	国家天文台_星系宇宙学研究部
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 3.Univ Arizona, Dept Phys, Tucson, AZ 85721 USA
推荐引用方式 GB/T 7714	Cai, Yan-Chuan,Pan, Jun,Zhao, Yong-Heng,et al. DWT power spectrum of the two-degree field galaxy redshift survey[J]. CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS,2008,8(2):159-178.
APA	Cai, Yan-Chuan,Pan, Jun,Zhao, Yong-Heng,Feng, Long-Long,&Fang, Li-Zhi.(2008).DWT power spectrum of the two-degree field galaxy redshift survey.CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS,8(2),159-178.
MLA	Cai, Yan-Chuan,et al."DWT power spectrum of the two-degree field galaxy redshift survey".CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS 8.2(2008):159-178.