Uchuu-ν<SUP>2</SUP>GC galaxies and AGN: cosmic variance forecasts of high-redshift AGN for JWST, Euclid, and LSST

DOI: 
10.1093/mnras/stad2401
Publication date: 
11/11/2023
Main author: 
Oogi, Taira
IAA authors: 
Prada, Francisco;Ruedas, José
Authors: 
Oogi, Taira;Ishiyama, Tomoaki;Prada, Francisco;Sinha, Manodeep;Croton, Darren;Cora, Sofía A.;Jullo, Eric;Klypin, Anatoly A.;Nagashima, Masahiro;López Cacheiro, J.;Ruedas, José;Kobayashi, Masakazu A. R.;Makiya, Ryu
Journal: 
Monthly Notices of the Royal Astronomical Society
Publication type: 
Article
Volume: 
525
Pages: 
3879
Abstract: 
Measurements of the luminosity function of active galactic nuclei (AGN) at high redshift (z ≳ 6) are expected to suffer from field-to-field variance, including cosmic and Poisson variances. Future surveys, such as those from the Euclid telescope and JWST, will also be affected by field variance. We use the Uchuu simulation, a state-of-the-art cosmological N-body simulation with 2.1 trillion particles in a volume of 25.7 Gpc<SUP>3</SUP>, combined with a semi-analytic galaxy and AGN formation model, to generate the Uchuu-ν<SUP>2</SUP>GC catalogue, publicly available, that allows us to investigate the field-to-field variance of the luminosity function of AGN. With this Uchuu-ν<SUP>2</SUP>GC model, we quantify the cosmic variance as a function of survey area, AGN luminosity, and redshift. In general, cosmic variance decreases with increasing survey area and decreasing redshift. We find that at z ~ 6 - 7, the cosmic variance depends weakly on AGN luminosity. This is because the typical mass of dark matter haloes in which AGN reside does not significantly depend on luminosity. Due to the rarity of AGN, Poisson variance dominates the total field-to-field variance, especially for bright AGN. We also examine the effect of parameters related to galaxy formation physics on the field variance. We discuss uncertainties present in the estimation of the faint-end of the AGN luminosity function from recent observations, and extend this to make predictions for the expected number of AGN and their variance for upcoming observations with Euclid, JWST, and the Legacy Survey of Space and Time (LSST).
Database: 
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2023MNRAS.525.3879O/abstract
ADS Bibcode: 
2023MNRAS.525.3879O
Keywords: 
methods: numerical;catalogues;galaxies: formation;galaxies: nuclei;large-scale structure of Universe;cosmology: theory;Astrophysics - Astrophysics of Galaxies;Astrophysics - Cosmology and Nongalactic Astrophysics