A limit of the anisotropy of the microwave background radiation on arc minute scales

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168039· OSTI ID:7143543

Readhead, A C.S.; Lawrence, C R; Myers, S T; Sargent, W L.W.; Hardebeck, H E ^[1]

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1. Owens Valley Radio Observatory, Pasadena, CA (USA)

After adjustment for observational parameters, various models predict an upper anisotropy limit of microwave background radiation of delta T/T less than 0.00017 at the 95 percent confidence level for uncorrelated patches of sky that are uniform on a 2-arcsec scale. This limit is more than a factor of 2 lower than previous limits on comparable angular scales. Results obtained assuming Gaussian fluctuations place useful constraints on models of galaxy formation based on adiabatic or isocurvature fluctuations in baryonic matter, provided that any reionization of the intergalactic medium occurred at z less than 40. Adiabatic models are ruled out with greater than 95 percent confidence, and isocurvature models with Omega less than 0.8 are inconsistent with the measured limits. Nonbaryonic models with early reionization predict anisotropy levels up to a factor of 3 below the present limit. The lowest predictions come from models with biased galaxy formation, nonbaryonic matter, and early reionization and are as much as a factor of 10 below the present sensitivity limit. The predictions of most popular contending theories of galaxy formation are within reach of the techniques used in this study. 112 refs.

• OSTI ID: 7143543
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 346; 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
ADIABATIC PROCESSES
ANISOTROPY
ASTROPHYSICS
BARYONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ERRORS
FERMIONS
GALACTIC EVOLUTION
HADRONS
IONIZATION
LIMITING VALUES
MICROWAVE RADIATION
RADIATIONS
RELICT RADIATION