2014/05/31 by Martin Feix, Adi Nusser, Enzo Branchini · 1 citation
Physics and Astronomy · #Amplitude #Astronomy and Astrophysical Research #Bin #COSMIC cancer database #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Luminosity #Peculiar velocity #Redshift #Tilt (camera) #astro-ph.CO
paper · pdf · doi:10.1088/1475-7516/2014/09/019
published as JCAP09(2014)019 · 21 pages, 11 figures, accepted version
arxiv created 2014/08/25 · openalex publication_date 2014/09/08 · arxiv updated 2014/09/10 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Spatial modulations in the distribution of observed luminosities (computed using redshifts) of ∼ 5 × 10 5 galaxies from the SDSS Data Release 7, probe the cosmic peculiar velocity field out to z ∼ 0.1. Allowing for luminosity evolution, the r -band luminosity function, determined via a spline-based estimator, is well represented by a Schechter form with M ⋆ ( z )-5 log 10 h = -20.52 -1.6( z -0.1)± 0.05 and α ⋆ = -1.1± 0.03. Bulk flows and higher velocity moments in two redshift bins, 0.02 < z < 0.07 and 0.07 < z < 0.22, agree with the predictions of the ΛCDM model, as obtained from mock galaxy catalogs designed to match the observations. Assuming a ΛCDM model, we estimate σ 8 ≈ 1.1± 0.4 for the amplitude of the linear matter power spectrum, where the low accuracy is due to the limited number of galaxies. While the low z bin is robust against coherent photometric uncertainties, the bias of results from the second bin is consistent with the ∼1% magnitude tilt reported by the SDSS collaboration. The systematics are expected to have a significantly lower impact in future datasets with larger sky coverage and better photometric calibration.