A Caltech Library Service

The 2dF Galaxy Redshift Survey: the nature of the relative bias between galaxies of different spectral type

Conway, Edward and Maddox, Steve and Wild, Vivienne and Peacock, John A. and Hawkins, Ed and Norberg, Peder and Madgwick, Darren S. and Baldry, Ivan K. and Baugh, Carlton M. and Bland-Hawthorn, Joss and Bridges, Terry and Cannon, Russell and Cole, Shaun and Colless, Matthew and Collins, Chris and Couch, Warrick and Dalton, Gavin and De Propris, Roberto and Driver, Simon P. and Efstathiou, George and Ellis, Richard S. and Frenk, Carlos S. and Glazebrook, Karl and Jackson, Carole and Jones, Bryn and Lahav, Ofer and Lewis, Ian and Lumsden, Stuart and Percival, Will and Peterson, Bruce A. and Sutherland, Will and Taylor, Keith (2005) The 2dF Galaxy Redshift Survey: the nature of the relative bias between galaxies of different spectral type. Monthly Notices of the Royal Astronomical Society, 356 (2). pp. 456-474. ISSN 0035-8711. doi:10.1111/j.1365-2966.2004.08446.x.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present an analysis of the relative bias between early- and late-type galaxies in the Two-degree Field Galaxy Redshift Survey (2dFGRS) – as defined by the η parameter of Madgwick et al., which quantifies the spectral type of galaxies in the survey. We calculate counts in cells for flux-limited samples of early- and late-type galaxies, using approximately cubical cells with sides ranging from 7 to 42 h⁻¹ Mpc. We measure the variance of the counts in cells using the method of Efstathiou et al., which we find requires a correction for a finite volume effect equivalent to the integral constraint bias of the autocorrelation function. Using a maximum-likelihood technique we fit lognormal models to the one-point density distribution, and develop methods of dealing with biases in the recovered variances resulting from this technique. We then examine the joint density distribution function, f(δ_E, δ_L), and directly fit deterministic bias models to the joint counts in cells. We measure a linear relative bias of ≈1.3, which does not vary significantly with ℓ. A deterministic linear bias model is, however, a poor approximation to the data, especially on small scales (ℓ≤ 28h⁻¹ Mpc) where deterministic linear bias is excluded at high significance. A power-law bias model with index b₁≈ 0.75 is a significantly better fit to the data on all scales, although linear bias becomes consistent with the data for ℓ ≳ 40h⁻¹ Mpc.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Norberg, Peder0000-0002-5875-0440
Baugh, Carlton M.0000-0002-9935-9755
Bland-Hawthorn, Joss0000-0001-7516-4016
Colless, Matthew0000-0001-9552-8075
Ellis, Richard S.0000-0001-7782-7071
Alternate Title:The nature of the relative bias between galaxies of different spectral type in 2dFGRS
Additional Information:© 2004 RAS. Accepted 2004 September 23. Received 2004 July 19; in original form 2004 April 15. The 2dFGRS was made possible through the dedicated efforts of the staff of the Anglo-Australian Observatory, both in creating the 2dF instrument and in supporting it on the telescope. JAP and OL thank PPARC for their Senior Research Fellowships.
Funding AgencyGrant Number
Particle Physics and Astronomy Research Council (PPARC)UNSPECIFIED
Subject Keywords:surveys, galaxies: distances and redshifts, galaxies: statistics, large-scale structure of Universe
Issue or Number:2
Record Number:CaltechAUTHORS:20200713-181756346
Persistent URL:
Official Citation:Edward Conway, Steve Maddox, Vivienne Wild, John A. Peacock, Ed Hawkins, Peder Norberg, Darren S. Madgwick, Ivan K. Baldry, Carlton M. Baugh, Joss Bland-Hawthorn, Terry Bridges, Russell Cannon, Shaun Cole, Matthew Colless, Chris Collins, Warrick Couch, Gavin Dalton, Roberto De Propris, Simon P. Driver, George Efstathiou, Richard S. Ellis, Carlos S. Frenk, Karl Glazebrook, Carole Jackson, Bryn Jones, Ofer Lahav, Ian Lewis, Stuart Lumsden, Will Percival, Bruce A. Peterson, Will Sutherland, Keith Taylor, The 2dF Galaxy Redshift Survey: the nature of the relative bias between galaxies of different spectral type, Monthly Notices of the Royal Astronomical Society, Volume 356, Issue 2, January 2005, Pages 456–474,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104369
Deposited By: Rebecca Minjarez
Deposited On:16 Jul 2020 16:17
Last Modified:16 Nov 2021 18:31

Repository Staff Only: item control page