TY - JOUR

T1 - Multiwavelength consensus of large-scale linear bias

AU - Pan, Hengxing

AU - Obreschkow, Danail

AU - Howlett, Cullan

AU - Lagos, Claudia del P.

AU - Elahi, Pascal J.

AU - Baugh, Carlton

AU - Gonzalez-Perez, Violeta

PY - 2020/3

Y1 - 2020/3

N2 - We model the large-scale linear galaxy bias b(g)(x, z) as a function of redshift z and observed absolute magnitude threshold x for broad-band continuum emission from the far-infrared to ultraviolet, as well as for prominent emission lines, such as the H alpha, H beta, Ly a, and [O II] lines. The modelling relies on the semi-analytic galaxy formation model GALFORM, run on the state-of-the-art N-body simulation SURFS with the Planck 2015 cosmology. We find that both the differential bias at observed absolute magnitude x and the cumulative bias for magnitudes brighter than x can be fitted with a five-parameter model: b(g)(x, z) = a + b(1 + z)(e)(1 + exp [(x - c)d]). We also find that the bias for the continuum bands follows a very similar form regardless of wavelength due to the mixing of star-forming and quiescent galaxies in a magnitude-limited survey. Differences in bias only become apparent when an additional colour separation is included, which suggest extensions to this work could look at different colours at fixed magnitude limits. We test our fitting formula against observations, finding reasonable agreement with some measurements within 1 sigma statistical uncertainties, and highlighting areas of improvement. We provide the fitting parameters for various continuum bands, emission lines, and intrinsic galaxy properties, enabling a quick estimation of the linear bias in any typical survey of large-scale structure.

AB - We model the large-scale linear galaxy bias b(g)(x, z) as a function of redshift z and observed absolute magnitude threshold x for broad-band continuum emission from the far-infrared to ultraviolet, as well as for prominent emission lines, such as the H alpha, H beta, Ly a, and [O II] lines. The modelling relies on the semi-analytic galaxy formation model GALFORM, run on the state-of-the-art N-body simulation SURFS with the Planck 2015 cosmology. We find that both the differential bias at observed absolute magnitude x and the cumulative bias for magnitudes brighter than x can be fitted with a five-parameter model: b(g)(x, z) = a + b(1 + z)(e)(1 + exp [(x - c)d]). We also find that the bias for the continuum bands follows a very similar form regardless of wavelength due to the mixing of star-forming and quiescent galaxies in a magnitude-limited survey. Differences in bias only become apparent when an additional colour separation is included, which suggest extensions to this work could look at different colours at fixed magnitude limits. We test our fitting formula against observations, finding reasonable agreement with some measurements within 1 sigma statistical uncertainties, and highlighting areas of improvement. We provide the fitting parameters for various continuum bands, emission lines, and intrinsic galaxy properties, enabling a quick estimation of the linear bias in any typical survey of large-scale structure.

KW - galaxies: large-scale bias

KW - galaxies: surveys

KW - galaxies: formation

KW - POWER-SPECTRUM ANALYSIS

KW - GALAXY REDSHIFT SURVEY

KW - STAR-FORMATION LAWS

KW - DARK-MATTER HALOES

KW - ALL-SKY SURVEY

KW - LUMINOSITY FUNCTION

KW - ASSEMBLY BIAS

KW - COSMIC EVOLUTION

KW - EMISSION-LINE

KW - MASS FUNCTION

U2 - 10.1093/mnras/staa222

DO - 10.1093/mnras/staa222

M3 - Journal article

VL - 493

SP - 747

EP - 764

JO - Royal Astronomical Society. Monthly Notices

JF - Royal Astronomical Society. Monthly Notices

SN - 0035-8711

IS - 1

ER -