Fluctuations in the microwave background at intermediate angular scales
An important distortion of the dipole pattern in the microwave background has been detected by two groups (Fabbri, Melchiorri, Guidi, and Natale; Boughn, Cheng, and Wilkinson). Peebles has suggested that this irregularity may arise from large-scale gradients in gravitational potential due to the irregular distribution of mass in clusters of galaxies. His theory anticipates anisotropies in the microwave background at smaller angular scales. We present the experimental evidence of microwave background fluctuations at an angular scale of 6/sup 0/, with an amplitude of (1.1 +- 0.2) x 10/sup -4/ K. Since the result has been obtained after subtraction for the galactic emission, its validity depends on the accuracy in extrapolating the gas-to-dust ratio to very small values of the neutral hydrogen column density. A larger dispersion in this ratio at high galactic latitudes would increase the dust contribution: In such a case, we have an upper limit of 4 x 10/sup -5/ K for the cosmic background anisotropies at 6/sup 0/, at 2 standard deviations.
- Research Organization:
- Istituto di Fisica dell'Universita di Roma
- OSTI ID:
- 5723084
- Journal Information:
- Astrophys. J., Lett. Ed.; (United States), Vol. 249:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
COSMIC RADIATION
FLUCTUATIONS
ANISOTROPY
BACKGROUND RADIATION
COSMIC DUST
COSMIC GASES
COSMOLOGY
DATA ANALYSIS
EMISSION
MICROWAVE RADIATION
DUSTS
ELECTROMAGNETIC RADIATION
FLUIDS
GASES
IONIZING RADIATIONS
RADIATIONS
VARIATIONS
640101* - Astrophysics & Cosmology- Cosmic Radiation