2018/04/24 by Zhongxu Zhai, Jeremy L. Tinker, Matthew R. Becker +6 · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Cluster analysis #Correlation function (quantum field theory) #Cosmology #Degeneracy (biology) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy formation and evolution #Gamma-ray bursts and supernovae #Halo #Redshift #astro-ph.CO #astro-ph.GA #astro-ph.IM
paper · pdf · doi:10.3847/1538-4357/ab0d7b
14 pages, 8 figures, 1 table; submitted to ApJ; the project webpage is available at https://aemulusproject.github.io ; typo in Figure 7 and caption updated, results unchanged
arxiv created 2018/04/24 · openalex created_date 2018/04/24 · openalex publication_date 2019/03/20 · arxiv updated 2019/04/03 · openalex updated_date 2026/08/05
Abstract Using the N -body simulations of the Aemulus Project, we construct an emulator for the nonlinear clustering of galaxies in real and redshift space. We construct our model of galaxy bias using the halo occupation framework, accounting for possible velocity bias. The model includes 15 parameters, including both cosmological and galaxy bias parameters. We demonstrate that our emulator achieves ∼1% precision at the scales of interest, 0.1 h −1 Mpc < r < 10 h −1 Mpc, and recovers the true cosmology when tested against independent simulations. Our primary parameters of interest are related to the growth rate of structure, f , and its degenerate combination, fσ 8 . Using this emulator, we show that the constraining power on these parameters monotonically increases as smaller scales are included in the analysis, all the way down to 0.1 h −1 Mpc. For a BOSS-like survey, the constraints on fσ 8 from r < 30 h −1 Mpc scales alone are nearly a factor of two tighter than those from the fiducial BOSS analysis of redshift-space clustering using perturbation theory at larger scales. The combination of real- and redshift-space clustering allows us to break the degeneracy between f and σ 8 , yielding an 11% constraint on f alone for a BOSS-like analysis. The current Aemulus simulations limit this model to surveys of massive galaxies. Future simulations will allow this framework to be extended to all galaxy target types, including emission-line galaxies.