Comparison of the ENEAR Peculiar Velocities with the PSCz Gravity Field

Authors

A Nusser, Technion – Israel Institute of Technology
L. N. da Costa, European Southern ObservatoryFollow
E Branchini, University of Groningen
M. Bernardi, The University of ChicagoFollow
M V. Alonso, Argentine National ObservatoryFollow
G Wegner, Dartmouth College

Document Type

Article

Publication Date

2001

Publication Title

Monthly Notices of the Royal Astronomical Society

Department

Department of Physics and Astronomy

Abstract

We present a comparison between the peculiar velocity field measured from the ENEAR all-sky Dn−σ catalogue and that derived from the galaxy distribution of the IRAS Point Source Catalog Redshift Survey (PSCz). The analysis is based on a modal expansion of these data in redshift space by means of spherical harmonics and Bessel functions. The effective smoothing scale of the expansion is almost linear with redshift reaching 1500kms⁻¹ at 3000kms⁻¹. The general flow patterns in the filtered ENEAR and PSCz velocity fields agree well within 6000kms⁻¹, assuming a linear biasing relation between the mass and the PSCz galaxies. The comparison allows us to determine the parameter β = Ω^0.6 / b, where Ω is the cosmological density parameter and b is the linear biasing factor. A likelihood analysis of the ENEAR and PSCz modes yields β = 0.5 ± 0.1, in good agreement with values obtained from Tully-Fisher surveys.

Dartmouth Digital Commons Citation

A Nusser; da Costa, L. N.; E Branchini; Bernardi, M.; Alonso, M V.; and Wegner, G, "Comparison of the ENEAR Peculiar Velocities with the PSCz Gravity Field" (2001). Dartmouth Scholarship. 1864.
https://digitalcommons.dartmouth.edu/facoa/1864