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dwtpowerspectrumofthetwodegreefieldgalaxyredshiftsurvey | |
YanChuan Cai1; Jun Pan1; YongHeng Zhao2; LongLong Feng1; LiZhi Fang3 | |
2008 | |
Source Publication | chinesejournalofastronomyandastrophysics |
ISSN | 1009-9271 |
Volume | 8Issue:2Pages:159 |
Abstract | 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. |
Language | 英语 |
Document Type | 期刊论文 |
Identifier | http://libir.pmo.ac.cn/handle/332002/28659 |
Collection | 中国科学院紫金山天文台 |
Affiliation | 1.中国科学院紫金山天文台 2.中国科学院国家天文台 3.亚利桑那大学 |
First Author Affilication | 中国科学院紫金山天文台 |
Recommended Citation GB/T 7714 | YanChuan Cai,Jun Pan,YongHeng Zhao,et al. dwtpowerspectrumofthetwodegreefieldgalaxyredshiftsurvey[J]. chinesejournalofastronomyandastrophysics,2008,8(2):159. |
APA | YanChuan Cai,Jun Pan,YongHeng Zhao,LongLong Feng,&LiZhi Fang.(2008).dwtpowerspectrumofthetwodegreefieldgalaxyredshiftsurvey.chinesejournalofastronomyandastrophysics,8(2),159. |
MLA | YanChuan Cai,et al."dwtpowerspectrumofthetwodegreefieldgalaxyredshiftsurvey".chinesejournalofastronomyandastrophysics 8.2(2008):159. |
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