TY - JOUR

T1 - The 2dF Galaxy Redshift Survey

T2 - The nature of the relative bias between galaxies of different spectral type

AU - Conway, Edward

AU - Maddox, Steve

AU - Wild, Vivienne

AU - Peacock, John A.

AU - Hawkins, Ed

AU - Norberg, Peder

AU - Madgwick, Darren S.

AU - Baldry, Ivan K.

AU - Baugh, Carlton M.

AU - Bland-Hawthorn, Joss

AU - Bridges, Terry

AU - Cannon, Russell

AU - Cole, Shaun

AU - Colless, Matthew

AU - Collins, Chris

AU - Couch, Warrick

AU - Dalton, Gavin

AU - De Propris, Roberto

AU - Driver, Simon P.

AU - Efstathiou, George

AU - Ellis, Richard S.

AU - Frenk, Carlos S.

AU - Glazebrook, Karl

AU - Jackson, Carole

AU - Jones, Bryn

AU - Lahav, Ofer

AU - Lewis, Ian

AU - Lumsden, Stuart

AU - Percival, Will

AU - Peterson, Bruce A.

AU - Sutherland, Will

AU - Taylor, Keith

PY - 2005/1/11

Y1 - 2005/1/11

N2 - 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(δE, δL), 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 ≤ 28 h-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 ≳ 40 h-1 Mpc.

AB - 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(δE, δL), 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 ≤ 28 h-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 ≳ 40 h-1 Mpc.

KW - Galaxies: distances and redshifts

KW - Galaxies: statistics

KW - Large-scale structure of Universe

KW - Surveys

UR - http://www.scopus.com/inward/record.url?scp=11844251304&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2966.2004.08446.x

DO - 10.1111/j.1365-2966.2004.08446.x

M3 - Review article

SN - 0035-8711

VL - 356

SP - 456

EP - 474

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 2

ER -