Preliminary results from the COBE differential microwave radiometers - Large angular scale isotropy of the cosmic microwave background

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/185988· OSTI ID:5468665

Smoot, G F; Aymon, J; Bennett, C L; Kogut, A; Backus, C ^[1]

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1. California, University, Berkeley (USA) NASA, Goddard Space Flight Center, Greenbelt, MD (USA) ST Systems, Inc., Lanham, MD (USA)

Preliminary but precise micowave maps are presented of the sky, and thus of the early universe, derived as the first results from the Differential Microwave Radiometers experiment aboard COBE. The dipole anisotropy attributed to the motion of the solar system with respect to the CMB reference frame shows strongly in all six sky maps and is consistent with a Doppler-shifted thermal spectrum. The best-fitted dipole has amplitude 3.3 + or - 0.2 mK in the direction (alpha, delta) = 11.2 h + or - 0.2 h, -7 deg + or - 2 deg (J2000) or (l,b) = 265 deg + or - 2 deg, 48 deg + or - 2 deg. There is no clear evidence in the maps for any other large angular-scale feature. Limits on Delta T/T0 of 3 x 10 to the -5th (T0 = 2.735 K), 4 x 10 to the -5th, and 4 x 10 to the -5th are found for the rms quadrupole amplitude, monochromatic fluctuations, and Gaussian fluctuations, respectively. These measurements place the most severe constraints to date on many potential physical processes in the early universe. 25 refs.

• OSTI ID: 5468665
• Journal Information: Astrophysical Journal; (United States), Journal Name: Astrophysical Journal; (United States) Vol. 371; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640106* -- Astrophysics & Cosmology-- Cosmology
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
BACKGROUND RADIATION
COSMOLOGY
ELECTROMAGNETIC RADIATION
GALAXIES
ISOTROPY
LIMITING VALUES
MAPS
MEASURING INSTRUMENTS
MICROWAVE RADIATION
MILKY WAY
RADIATION DETECTORS
RADIATIONS
RADIOMETERS
RELICT RADIATION
SATELLITES
SOLAR SYSTEM
UNIVERSE