期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 430, 期 3, 页码 1617-1635出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/sts698
关键词
methods: observational; methods: statistical; intergalactic medium; cosmology: cosmic background radiation; cosmology: observations; large-scale structure of Universe
资金
- National Aeronautics and Space Administration
- National Science Foundation
- CITA
- Government of Canada
- NSF [AST 07-08849, AST 09-08693]
- NSERC
- Government of Canada through Industry Canada
- Province of Ontario through the Ministry of Research and Innovation
- NASA Office of Space Science
Peculiar velocities in the nearby Universe can be measured via the kinetic Sunyaev-Zel'dovich (kSZ) effect. Using a statistical method based on an optimized cross-correlation with nearby galaxies, we extract the kSZ signal generated by plasma halo of galaxies from the cosmic microwave background (CMB) temperature anisotropies observed by the Wilkinson Microwave Anisotropy Probe (WMAP). Marginalizing over the thermal Sunyaev-Zel'dovich contribution from clusters of galaxies, possible unresolved point source contamination, and Galactic foregrounds, we find a kSZ bulk flow signal present at the similar to 90 per cent confidence level in the seven-year WMAP data. When only galaxies within 50 h(-1) Mpc are included in the kSZ template, we find a bulk flow in the CMB frame of vertical bar V vertical bar = 533 +/- 263 km s(-1), in the direction l = 324 +/- 27, b = -7 +/- 17, consistent with bulk flow measurements on a similar scale using classical distance indicators. We show how this comparison constrains, for the first time, the (ionized) baryonic budget in the local universe. On very large (similar to 500 h(-1) Mpc) scales, we find a 95 per cent upper limit of 470 km s(-1), inconsistent with some analyses of bulk flow of clusters from the kSZ. We estimate that the significance of the bulk flow signal may increase to 3 sigma-5 sigma using data from the Planck probe.
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