Linear bias forecasts for emission line cosmological surveys

Merson, Alexander; Smith, Alex; Benson, Andrew; Wang, Yun; Baugh, Carlton

Abstract

We forecast the linear bias for Hα-emitting galaxies at high redshift. To simulate a Euclid-like and a WFIRST-like survey, we place galaxies into a large-volume dark matter halo lightcone by sampling a library of luminosity-dependent halo occupation distributions (HODs), which is constructed using a physically motivated galaxy formation model. We calibrate the dust attenuation in the lightcones such that they are able to reproduce the Hα luminosity function or the Hα cumulative number counts. The angle-averaged galaxy correlation function is computed for each survey in redshift slices of width Δz = 0.2. In each redshift bin the linear bias can be fitted with a single, scale-independent value that increases with increasing redshift. Fitting for the evolution of linear bias with redshift, we find that our Euclid-like and WFIRST-like surveys are both consistent within error with the relation b(z) = 0.7z + 0.7. Our bias forecasts are consistent with bias measurements from the HiZELS survey. We find that the Euclid-like and WFIRST-like surveys yield linear biases that are broadly consistent within error, most likely due to the HOD for the WFIRST-like survey having a steeper power-law slope towards larger halo masses.

Citation

Merson, A., Smith, A., Benson, A., Wang, Y., & Baugh, C. (2019). Linear bias forecasts for emission line cosmological surveys. Monthly Notices of the Royal Astronomical Society, 486(4), 5737-5765. https://doi.org/10.1093/mnras/stz1204

• Journal Article Type: Article
• Acceptance Date: Apr 18, 2019
• Online Publication Date: May 30, 2019
• Publication Date: Jul 31, 2019
• Deposit Date: May 7, 2019
• Publicly Available Date: May 7, 2019
• 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: 486
• Issue: 4
• Pages: 5737-5765
• DOI: https://doi.org/10.1093/mnras/stz1204
• Public URL: https://durham-repository.worktribe.com/output/1331434