Bulk flow and shear moments of the SFI++ survey |
| |
Authors: | Hume A. Feldman Richard Watkins |
| |
Affiliation: | Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA;Department of Physics, Willamette University, Salem, OR 97301, USA |
| |
Abstract: | We find the nine bulk flow and shear moments from the SFI++ survey, as well as for subsamples of group and field galaxies. We constrain the velocity power spectrum shape parameter Γ in linear theory using these moments. A likelihood function for Γ was found after marginalizing over the power spectrum amplitude σ8Ω0.6m using constraints obtained from comparisons between redshift surveys and peculiar velocity data. We have estimated the velocity noise σ* from the data since without it our results may be biased. We also performed a statistical analysis of the difference between the field and group catalogues and found that the results from each reflect the same underlying large-scale flows. We found that we can constrain the power spectrum shape parameter to be Γ= 0.15+0.18−0.08 for the groups catalogue and Γ= 0.09+0.04−0.04 for the field galaxy catalogue in fair agreement with the value from Wilkinson Microwave Anisotropy Probe . |
| |
Keywords: | galaxies: kinematics and dynamics galaxies: statistics cosmology: observations cosmology: theory distance scale large-scale structure of Universe |
|
|