UNIT project: Universe N-body simulations for the Investigation of Theoretical models from galaxy surveys. Issue 1 (4th May 2019)

• Record Type: Journal Article
• Authors: Chuang, Chia-Hsun; Yepes, Gustavo; Kitaura, Francisco-Shu; Pellejero-Ibanez, Marcos; Rodríguez-Torres, Sergio; Feng, Yu; Metcalf, Robert Benton; Wechsler, Risa H; Zhao, Cheng; To, Chun-Hao; Alam, Shadab; Banerjee, Arka; DeRose, Joseph; Giocoli, Carlo; Knebe, Alexander; Reyes, Guillermo
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 487:Issue 1(2019)
• Page Start: 48
• Page End: 59
• Publication Date: 2019-05-04
• Subjects: large-scale structure of the Universe; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz1233
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We present the UNIT N -body cosmological simulations project, designed to provide precise predictions for non-linear statistics of the galaxy distribution. We focus on characterizing statistics relevant to emission line and luminous red galaxies in the current and upcoming generation of galaxy surveys. We use a suite of precise particle mesh simulations (fastpm ) as well as with full N -body calculations with a mass resolution of${\sim } 1.2\times 10^9\, h^{-1}$ M⊙ to investigate the recently suggested technique of Angulo and Pontzen to suppress the variance of cosmological simulations. We study redshift-space distortions, cosmic voids, higher order statistics from z = 2 down to 0. We find that both two- and three-point statistics are unbiased. Over the scales of interest for baryon acoustic oscillations and redshift-space distortions, we find that the variance is greatly reduced in the two-point statistics and in the cross-correlation between haloes and cosmic voids, but is not reduced significantly for the three-point statistics. We demonstrate that the accuracy of the two-point correlation function for a galaxy survey with effective volume of 20 ( h −1 Gpc) 3 is improved by about a factor of 40, indicating that two pairs of simulations with a volume of 1 ( h −1 Gpc) 3 lead to the equivalent variance of ∼150 such simulations. The N -body simulations presented here thus provide an effective survey volume of about seven times the effective survey volume of Dark Energy Spectroscopic Instrument or Euclid . The data from this project, including dark matter fields, halo catalogues, and their clustering statistics, are publicly available.