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Title: Four-year COBE DMR cosmic microwave background observations: Mapsand basic results

Abstract

In this Letter we present a summary of the spatial properties of the cosmic microwave background radiation based on the full 4 yr of COBE Differential Microwave Radiometer (DMR) observations, with additional details in a set of companion Letters. The anisotropy is consistent with a scale-invariant power-law model and Gaussian statistics. With full use of the multifrequency 4 yr DMR data, including our estimate of the effects of Galactic emission, we find a power-law spectral index of n = 1.2 +/- 0.3 and a quadrupole normalization Q(rms-PS) = 15.31(-2.8)(+3.8) mu K. For n = 1 the best-fit normalization is Q(rms-PS/n=1) = 18 +/- 1.6 mu K. These values are consistent with both our previous 1 yr and 2 yr results. The results include use of the l = 2 quadrupole term; exclusion of this term gives consistent results, but with larger uncertainties. The final DMR 4 yr sky maps, presented in this Letter, portray an accurate overall visual impression of the anisotropy since the signal-to-noise ratio is similar to 2 per 10 degrees sky map patch. The improved signal-to-noise ratio of the 4 yr maps also allows for improvements in Galactic modeling and limits on non-Gaussian statistics.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
COLLABORATION - NASA
OSTI Identifier:
894241
Report Number(s):
LBNL-61840
Journal ID: ISSN 0004-637X; ASJOAB; TRN: US200701%%276
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 464; Related Information: Journal Publication Date: 06/10/1996; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANISOTROPY; QUADRUPOLES; RADIATIONS; RADIOMETERS; RELICT RADIATION; SIGNAL-TO-NOISE RATIO; SIMULATION; SKY; STATISTICS

Citation Formats

Bennett, C.L., Banday, A.J., Gorski, K.M., Hinshaw, G., Jackson,P., Keegstra, P., Kogut, A., Smoot, G.F., Wilkinson, D.T., and Wright, E.L. Four-year COBE DMR cosmic microwave background observations: Mapsand basic results. United States: N. p., 1996. Web. doi:10.1086/310075.
Bennett, C.L., Banday, A.J., Gorski, K.M., Hinshaw, G., Jackson,P., Keegstra, P., Kogut, A., Smoot, G.F., Wilkinson, D.T., & Wright, E.L. Four-year COBE DMR cosmic microwave background observations: Mapsand basic results. United States. doi:10.1086/310075.
Bennett, C.L., Banday, A.J., Gorski, K.M., Hinshaw, G., Jackson,P., Keegstra, P., Kogut, A., Smoot, G.F., Wilkinson, D.T., and Wright, E.L. Wed . "Four-year COBE DMR cosmic microwave background observations: Mapsand basic results". United States. doi:10.1086/310075.
@article{osti_894241,
title = {Four-year COBE DMR cosmic microwave background observations: Mapsand basic results},
author = {Bennett, C.L. and Banday, A.J. and Gorski, K.M. and Hinshaw, G. and Jackson,P. and Keegstra, P. and Kogut, A. and Smoot, G.F. and Wilkinson, D.T. and Wright, E.L.},
abstractNote = {In this Letter we present a summary of the spatial properties of the cosmic microwave background radiation based on the full 4 yr of COBE Differential Microwave Radiometer (DMR) observations, with additional details in a set of companion Letters. The anisotropy is consistent with a scale-invariant power-law model and Gaussian statistics. With full use of the multifrequency 4 yr DMR data, including our estimate of the effects of Galactic emission, we find a power-law spectral index of n = 1.2 +/- 0.3 and a quadrupole normalization Q(rms-PS) = 15.31(-2.8)(+3.8) mu K. For n = 1 the best-fit normalization is Q(rms-PS/n=1) = 18 +/- 1.6 mu K. These values are consistent with both our previous 1 yr and 2 yr results. The results include use of the l = 2 quadrupole term; exclusion of this term gives consistent results, but with larger uncertainties. The final DMR 4 yr sky maps, presented in this Letter, portray an accurate overall visual impression of the anisotropy since the signal-to-noise ratio is similar to 2 per 10 degrees sky map patch. The improved signal-to-noise ratio of the 4 yr maps also allows for improvements in Galactic modeling and limits on non-Gaussian statistics.},
doi = {10.1086/310075},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = ,
volume = 464,
place = {United States},
year = {1996},
month = {1}
}