Multiwavelength consensus of large-scale linear bias

Pan, Hengxing; Obreschkow, Danail; Howlett, Cullan; Lagos, Claudia del P; Elahi, Pascal J; Baugh, Carlton; Gonzalez-Perez, Violeta

Abstract

We model the large-scale linear galaxy bias bg(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 α, H β, 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: bg(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 1σ 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.

Citation

Pan, H., Obreschkow, D., Howlett, C., Lagos, C. D. P., Elahi, P. J., Baugh, C., & Gonzalez-Perez, V. (2020). Multiwavelength consensus of large-scale linear bias. Monthly Notices of the Royal Astronomical Society, 493(1), 747-764. https://doi.org/10.1093/mnras/staa222

• Journal Article Type: Article
• Acceptance Date: Jan 5, 2020
• Online Publication Date: Jan 25, 2020
• Publication Date: Mar 31, 2020
• Deposit Date: Mar 25, 2020
• Publicly Available Date: Mar 25, 2020
• 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: 493
• Issue: 1
• Pages: 747-764
• DOI: https://doi.org/10.1093/mnras/staa222
• Public URL: https://durham-repository.worktribe.com/output/1274064