The 2dF Galaxy Redshift Survey: the bias of galaxies and the density of the Universe

Verde, L.; Heavens, A.F.; Percival, W.J.; Matarrese, S.; Baugh, C.M.; Bland-Hawthorn, J.; Bridges, T.; Cannon, R.; Cole, S.; Colless, M.; Collins, C.; Couch, W.; Dalton, G.; De Propris, R.; Driver, S.P.; Efstathiou, G.; Ellis, R.S.; Frenk, C.S.; Glazebrook, K.; Jackson, C.; Lahav, O.; Lewis, I.; Lumsden, S.; Maddox, S.; Madgwick, D.; Norberg, P.; Peacock, J.A.; Peterson, B.A.; Sutherland, W.; Taylor, K.

doi:10.1046/j.1365-8711.2002.05620.x

The 2dF Galaxy Redshift Survey: the bias of galaxies and the density of the Universe

Verde, L.; Heavens, A.F.; Percival, W.J.; Matarrese, S.; Baugh, C.M.; Bland-Hawthorn, J.; Bridges, T.; Cannon, R.; Cole, S.; Colless, M.; Collins, C.; Couch, W.; Dalton, G.; De Propris, R.; Driver, S.P.; Efstathiou, G.; Ellis, R.S.; Frenk, C.S.; Glazebrook, K.; Jackson, C.; Lahav, O.; Lewis, I.; Lumsden, S.; Maddox, S.; Madgwick, D.; Norberg, P.; Peacock, J.A.; Peterson, B.A.; Sutherland, W.; Taylor, K.

Authors

L. Verde

A.F. Heavens

W.J. Percival

S. Matarrese

Professor Carlton Baugh c.m.baugh@durham.ac.uk
Professor

J. Bland-Hawthorn

T. Bridges

R. Cannon

Professor Shaun Cole shaun.cole@durham.ac.uk
Director of the Institute for Computational Cosmology

M. Colless

C. Collins

W. Couch

G. Dalton

R. De Propris

S.P. Driver

G. Efstathiou

R.S. Ellis

Professor Carlos Frenk c.s.frenk@durham.ac.uk
Professor

K. Glazebrook

C. Jackson

O. Lahav

I. Lewis

S. Lumsden

S. Maddox

D. Madgwick

Professor Peder Norberg peder.norberg@durham.ac.uk
Professor

J.A. Peacock

B.A. Peterson

W. Sutherland

K. Taylor

Abstract

We compute the bispectrum of the 2dF Galaxy Redshift Survey (2dFGRS) and use it to measure the bias parameter of the galaxies. This parameter quantifies the strength of clustering of the galaxies relative to the mass in the Universe. By analysing 80 × 106 triangle configurations in the wavenumber range 0.1 < k < 0.5 h Mpc−1 (i.e. on scales roughly between 5 and 30 h−1 Mpc) we find that the linear bias parameter is consistent with unity: b1= 1.04 ± 0.11, and the quadratic (non-linear) bias is consistent with zero: b2=−0.054 ± 0.08. Thus, at least on large scales, optically selected galaxies do indeed trace the underlying mass distribution. The bias parameter can be combined with the 2dFGRS measurement of the redshift distortion parameter β≃Ωm0.6/b1, to yield Ωm= 0.27 ± 0.06 for the matter density of the Universe, a result that is determined entirely from this survey, independent of other data sets. Our measurement of the matter density of the Universe should be interpreted as Ωm at the effective redshift of the survey (z= 0.17).

Citation

Verde, L., Heavens, A., Percival, W., Matarrese, S., Baugh, C., Bland-Hawthorn, J., …Taylor, K. (2002). The 2dF Galaxy Redshift Survey: the bias of galaxies and the density of the Universe. Monthly Notices of the Royal Astronomical Society, 335(2), 432-440. https://doi.org/10.1046/j.1365-8711.2002.05620.x

Journal Article Type	Article
Publication Date	2002-09
Deposit Date	Apr 19, 2011
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	335
Issue	2
Pages	432-440
DOI	https://doi.org/10.1046/j.1365-8711.2002.05620.x
Public URL	https://durham-repository.worktribe.com/output/1510369