1999/06/22 by Silvia Mollerach, S. Mollerach, V. J. Martinez +7
Physics and Astronomy · #Amplitude #Anisotropy #Cosmology and Gravitation Theories #Microwave #Normalization (sociology) #Radio Astronomy Observations and Technology #Scattering #Spectral analysis #Spectral index #Superconducting and THz Device Technology #Surface finish #Surface roughness #astro-ph
paper · pdf · doi:10.1086/307874
17 pages, 4 figures (1 in colour), LaTeX, uses aaspp4.sty, ApJ, in press, November 1, 1999 issue, Vol. 525 #1
arxiv created 1999/06/22 · openalex publication_date 1999/11/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We propose an alternative analysis of the microwave background temperature anisotropy maps that is based on the study of the roughness of natural surfaces. We apply it to large-angle anisotropies, such as those measured by the COBE Differential Microwave Radiometer (DMR). We show that for a large signal-to-noise ratio experiment, the spectral index can be determined independently of the normalization. We then analyze the 4 yr COBE map and find that for a flat Ω = 1 universe, the best-fitting value for the spectral index is n = 1.15 and for the amplitude is Q rms-PS = 14.1 μK. For n = 1, the best-fitting normalization is Q rms-PS | n =1 = 16.2 μK.