Annu. Rev. Astron. Astrophys. 1992. 30: 653-703
Copyright © 1993 by . All rights reserved

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3.3.2 OBSERVATIONS IN ANTARCTICA Andreani et al have carried out observations in Antarctica at wavelengths of 2 mm, 1 mm and 350 µm (Andreani et al 1990a, b, 1991a, b). Their instrument was an off-axis parabola flux collector 1 meter in diameter with a 1° beam. The flux collector was wobbled at 8 Hz to give a beamthrow of 2°.5 on the sky. Their 2 mm observations showed a correlation with the IRAS 100 µm data, and they concluded that they had detected a cold (6-15 K) dust component which was well correlated with a warmer (~ 30 K) dust component detected by IRAS. They therefore extrapolated the IRAS 100 µm measurements to 2 mm, using the spectrum given by Andreani et al (1990b), and subtracted them from their 2 mm observations. They found that by this means they were able to reduce the variance in their 2 mm observations by a factor two. This still left detectable signals in their observations, which were unexplained, but they adopted a conservative approach and used the results to place the upper limit on fluctuations given in Table 4.

Table 4. 95% upper limits a on DeltaT/T at angular scales 1-20°

Experiment Angular
Scale
DeltaT/T x 105 Comments

Timbie & Wilkinson 1990 1°.7 7.4 43 GHz; monochromatic W(k)
1°.1 11 LR test, beta ~ 0.55; Gaussian W(k)
0°.4-3°.5 20 LR test, beta ~ 0.55; Gaussian W(k)
Andreani et al. 1990a 2°.5 33 150 GHz
29
Mandolesi et al. 1986 2°-10° 50-70 10 GHz
Cottingham 3°-25° 20 19.2 GHz; Monte Carlo tests on S'; Gaussian W(k)
Boughn et al 1991 10 19.2 GHz; Monte Carlo teste on S'; Gaussian W(k)
30° 4 Monte Carlo teste on S'; Gaussian W(k)
Page et al. 1990 10° 9.3 168 GHz; LR test, beta = 0.7; monochromatic W(k)
Meyer et al. 1991 13° 1.6 168 GHz; Monte Carlo tests on S', beta =0.92; monochromatic W(k)
3°-22° 4 Monte Carlo tests on S'; Gaussian W(k)

a As described in the text, some of these observations detected excess variance which could not be definitely attributed to the cosmic microwave background radiation.

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