2008/07/29 by M. Gervasi, M. Zannoni, A. Tartari +2
Physics and Astronomy · #Astronomy and Astrophysical Research #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/592134
accepted for publication in The Astrophysical Journal
arxiv created 2008/07/29 · openalex publication_date 2008/11/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
With the TRIS experiment we have performed absolute measurements of the sky brightness in a sky circle at δ = + 42° at the frequencies ν = 0.60, 0.82, and 2.5 GHz. In this paper we discuss the techniques used to separate the different contributions to the sky emission and give an evaluation of the absolute temperature of the CMB. For the blackbody temperature of the CMB we get T CMB th = 2.837 ± 0.129 ± 0.066 K at ν = 0.60 GHz, T CMB th = 2.803 ± 0.051 −0.300 +0.430 K at ν = 0.82 GHz, and T CMB th = 2.516 ± 0.139 ± 0.284 K at ν = 2.5 GHz. The first error bar is statistic (1 σ), while the second one is systematic. These results represent a significant improvement with respect to the previous measurements. We have also set new limits to the free-free distortions, –6.3 × 10 −6 < Y ff < 12.6 × 10 −6 , and slightly improved the Bose-Einstein upper limit, |μ| < 6 × 10 −5 , both at 95% confidence level.