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Figure 1:
Most accurate available results, taken by the COBE
satellite, and the experiments Boomerang, Maxima, DASI. We note
the lack of measurements between COBE and other experiments.
Archeops'main goal is to link these data sets with one single
measurement. Three different inflationnary models are also
plotted, showing the influence of the cosmological paremeters on
the power spectrum.
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After the extremely accurate CMB spectrum measurement by the COBE
satellite in 1989, proving that the radiation was a perfect blackbody
[6,7], and the first detection of
deviations [5] from the perfect homogeneity at the
level of 10 K, most experiments have concentrated on improving
the measurement of the anisotropies. In most theories and with
consistent available data, the statistical distribution of the CMB
anistropies is Gaussian. The anisotropies are therefore represented by
their spherical harmonic power spectrum (non-Gaussianity is
nevertheless looked for). The most accurate results are from COBE on
large angular scale ( 7 degrees) and on small angular scales ( 2
degrees) from Boomerang [8], Maxima
[9], and DASI [10] (see Figure
1). The intermediate angular scales, between
COBE and the other experiments, lack measurements, due to the small
sky coverage of these experiments. The main Archeops goal is to link
COBE and Boomerang-Maxima-DASI angular scales, with high-sensitivity
detectors covering a large fraction of sky (30% of the sky). Archeops
is also a testbed for Planck-HFI, using the same type of cryogenic
system and detectors; and it measures dust and galactic sources in a
polarized frequency band.
Next: Instrument and Scan-strategy
Up: amblard_cosmo01
Previous: Introduction
F.-Xavier Desert LAOG
2001-12-10