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Are Recent Peculiar Velocity Surveys Consistent?

Michael J. Hudson·Russell J. Smith·John R. Lucey·David J. Schlegel·Roger L. Davies
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Abstract

We compare the bulk flow of the SMAC sample to the predictions of popular cosmological models and to other recent large-scale peculiar velocity surveys. Both analyses account for aliasing of small-scale power due to the sparse and non-uniform sampling of the surveys. We conclude that the SMAC bulk flow is in marginal conflict with flat COBE-normalized Lambda-CDM models which fit the cluster abundance constraint. However, power spectra which are steeper shortward of the peak are consistent with all of the above constraints. When recent large-scale peculiar velocity surveys are compared, we conclude that all measured bulk flows (with the possible exception of that of Lauer & Postman) are consistent with each other given the errors, provided the latter allow for `cosmic covariance'. A rough estimate of the mean bulk flow of all surveys (except Lauer & Postman) is ~400 km/s towards l=270, b=0.

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Michael J. Hudson, Russell J. Smith, John R. Lucey, David J. Schlegel, Roger L. Davies. 1999-09-17. Are Recent Peculiar Velocity Surveys Consistent?. https://arxiv.org/abs/astro-ph/9909307

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