Low-frequency measurement of the spectrum of the cosmic microwave background radiation

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6894801

Levin, S M

As part of a larger effort to measure the spectrum of the cosmic background radiation (CBR) at low frequencies, the intensity of the CBR was measured at 1.410 GHz. The measurement was made by comparing the power received from the sky with the power received from a specially designed cooled calibration target with known properties. Sources of radiation other than the CBR were then identified and subtracted to calculate the antenna temperatures of the CBR at 1.410 GHz. The instrument used to measure the CBR was a total-power microwave radiometer with a 25 MHz bandwidth centered at 1.410 GHz. The radiometer had a noise temperature of 80 K, and sufficient data were taken that radiometer noise did not contribute significantly to the total measurement error. Identification and subtraction of signals from the Galaxy (0.7 K) and the Earth's atmosphere (0.8K) were also significant parts of the data reduction and error analysis. The brightness temperatures of the CBR at 1.410 GHz is 2.22 +/- 0.55 K. The spectrum of the CBR, as determined by this measurement and other published results, is consistent with a blackbody spectrum of temperature 2.741 +/- 0.016.

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 6894801
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKGROUND RADIATION
BLACKBODY RADIATION
BRIGHTNESS
COSMIC RADIATION
ELECTROMAGNETIC RADIATION
FREQUENCY RANGE
GHZ RANGE
GHZ RANGE 01-100
IONIZING RADIATIONS
MEASURING INSTRUMENTS
MEASURING METHODS
MICROWAVE RADIATION
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATION DETECTORS
RADIATIONS
RADIOMETERS