Linear bias forecasts for emission line cosmological surveys
Abstract
We forecast the linear bias for Hαemitting galaxies at high redshift. To simulate a Euclidlike and a WFIRSTlike survey, we place galaxies into a largevolume dark matter halo lightcone by sampling a library of luminositydependent 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 angleaveraged galaxy correlation function is computed for each survey in redshift slices of width ∆ z = 0.2. In each redshift bin the linear bias can be fitted with a single, scaleindependent value that increases with increasing redshift. Fitting for the evolution of linear bias with redshift, we find that our Euclidlike and WFIRSTlike 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 Euclidlike and WFIRSTlike surveys yield linear biases that are broadly consistent within error, most likely due to the HOD for the WFIRSTlike survey having a steeper powerlaw slope towards larger halo masses.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 July 2019
 DOI:
 10.1093/mnras/stz1204
 arXiv:
 arXiv:1903.02030
 Bibcode:
 2019MNRAS.486.5737M
 Keywords:

 methods: numerical;
 galaxies: formation;
 galaxies: statistics;
 largescale structure of Universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 30 pages including 8 pages of appendices. 17 figures. Accepted for publication in MNRAS following revisions