1994/03/10 by Charles H. Lineweaver, C. H. Lineweaver, G. F. Smoot +9 · 4 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Radio Astronomy Observations and Technology #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.1086/174920
11 pages + 3 figures, post-script file
arxiv created 1994/03/10 · openalex publication_date 1994/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The \it COBE DMR sky maps contain low-level correlated noise. We obtain estimates of the amplitude and pattern of the correlated noise from three techniques: angular averages of the covariance matrix, Monte Carlo simulations of two-point correlation functions, and direct analysis of the DMR maps. The results from the three methods are mutually consistent. The noise covariance matrix of a DMR sky map is diagonal to an accuracy of better than 1%. For a given sky pixel, the dominant noise covariance occurs with the ring of pixels at an angular separation of 60 ° due to the 60 ° separation of the DMR horns. The mean covariance at 60 ° is 0.45% +0.18-0.14 of the mean variance. Additionally, the variance in a given pixel is 0.7% greater than would be expected from a single beam experiment with the same noise properties. Auto-correlation functions suffer from a ∼ 1.5 σ positive bias at 60 ° while cross-correlations have no bias. Published \it COBE DMR results are not significantly affected by correlated noise. COBE pre-print 94-