期刊
ASTROPHYSICAL JOURNAL
卷 735, 期 2, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/735/2/77
关键词
cosmological parameters; large-scale structure of universe
资金
- ISRAEL SCIENCE FOUNDATION [203/09]
- German-Israeli Foundation for Research and Development
- Asher Space Research Institute
- WINNIPEG RESEARCH FUND
- NSF [AST-0807630]
- Agenzia Spaziale Italiana (ASI) [N.I/058/08/0]
We present a simple method for measuring cosmological bulk flows from large redshift surveys, based on the apparent dimming or brightening of galaxies due to their peculiar motion. It is aimed at estimating bulk flows of cosmological volumes containing large numbers of galaxies. Constraints on the bulk flow are obtained by minimizing systematic variations in galaxy luminosities with respect to a reference luminosity function measured from the whole survey. This method offers two advantages over more popular bulk flow estimators: it is independent of error-prone distance indicators and of the poorly known galaxy bias. We apply the method to the Two Micron All Sky Survey redshift survey to measure the local bulk flows of spherical shells centered on the Milky Way (MW). The result is consistent with that obtained by Nusser & Davis using the SFI++ catalogue of Tully-Fisher distance indicators. We also make an assessment of the ability of the method to constrain bulk flows at larger redshifts (z = 0.1-0.5) from next-generation data sets. As a case study we consider the planned EUCLID survey. Using this method we will be able to measure a bulk motion of similar to 200 km s(-1) of 10(6) galaxies with photometric redshifts, at the 3 sigma level for both z similar to 0.15 and z similar to 0.5. Thus, the method will allow us to put strong constraints on dark energy models as well as alternative theories for structure formation.
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