Steps toward the power spectrum of matter. I. The mean spectrum of galaxies

Citation
J. Einasto et al., Steps toward the power spectrum of matter. I. The mean spectrum of galaxies, ASTROPHYS J, 519(2), 1999, pp. 441-455
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004-637X → ACNP
Volume
519
Issue
2
Year of publication
1999
Part
1
Pages
441 - 455
Database
ISI
SICI code
0004-637X(19990710)519:2<441:STTPSO>2.0.ZU;2-A
Abstract
We calculate the mean power spectrum of all galaxies using published power spectra of galaxies and clusters of galaxies. On small scales we use the po wer spectrum derived from the two-dimensional distribution of Automatic Pla te Measuring Facility (APM) galaxies, since this sample is not influenced b y redshift distortions and is the largest and deepest sample of galaxies av ailable. On large scales we use power spectra derived from three-dimensiona l data for various galaxy and cluster samples which are reduced to real spa ce and in amplitude to the power spectrum of APM galaxies. We find that ava ilable data indicate the presence of two different populations in the nearb y universe. Clusters of galaxies sample a relatively large region in the un iverse where rich, medium, and poor superclusters are well represented. The ir mean power spectrum has a spike at wavenumber k = 0.05 +/- 0.01 h Mpc(-1 ), followed by an approximate power-law spectrum of index n approximate to -1.9 toward small scales. Some galaxy surveys (APM three-dimensional, IRAS QDOT, and SSRS+CfA2 130 Mpc) have similar spectra. The power spectrum found from the Las Campanas Redshift. Survey and IRAS 1.2 Jy surveys is flatter around the maximum, which may represent regions of the universe with medium -rich and poor superclusters. Differences in power spectra for these popula tions may partly be due to the survey geometries of the data sets in questi on and/or to features of the original data analysis.