2003/08/18 by Zuhui Fan, Z. H. Fan, Yanling Wu +1
Physics and Astronomy · #Astrophysics #Cluster (spacecraft) #Cosmology #Cosmology and Gravitation Theories #Dark energy #Equation of state #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Physics #Planck #Quantum mechanics #Redshift #astro-ph
paper · pdf · doi:10.1086/379065
published as Astrophys.J.598:713-719,2003 · ApJ in press
arxiv created 2003/08/18 · openalex publication_date 2003/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Sunyaev-Zel'dovich Effect (SZE) cluster surveys are anticipated to yield tight constraints on cosmological parameters such as the equation of state of dark energy. In this paper, we study the impact of relativistic corrections of the thermal SZE on the cluster number counts expected from a cosmological model and thus, assuming that other cosmological parameters are known to high accuracies, on the determination of the w parameter and σ8 from a SZE cluster survey, where w=p/ρ with p the pressure and ρ the density of dark energy, and σ8 is the rms of the extrapolated linear density fluctuation smoothed over 8\hboxMpch-1. For the purpose of illustrating the effects of relativistic corrections, our analyses mainly focus on ν=353 \hboxGHz and Slim=30\hboxmJy, where ν and Slim are the observing frequency and the flux limit of a survey, respectively. These observing parameters are relevant to the \it Planck survey. It is found that from two measurable quantities, the total number of SZE clusters and the number of clusters with redshift z≥ 0.5, σ8 and w can be determined to a level of ± 1% and ± 8%, respectively, with 1σ uncertainties from a survey of 10000\hboxdeg2. Relativistic effects are important in determining the central values of σ8 and w. If we choose the two quantities calculated relativistically from the flat cosmological model with σ8=0.8284 and w=-0.75 as input, the derived σ8 and w would be 0.819 and -0.81, respectively, if relativistic effects are wrongly neglected. The location of the resulting σ8 and w in the σ8-w plane is outside the 3σ region around the real central σ8 and w.