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 -