A description of these experiments was given in Lasenby &
Hancock [65]. Here we briefly summarise the relevant features. The Tenerife
experiments constitute a suite of three instruments, working at
10, 15 and 33 GHz, designed and built at Jodrell Bank
(Davies
et al.
1992 [45], 1996 [44]) and operated by the IAC in-situ on Tenerife island. Data are
taken by drift scanning in right ascension at fixed declination
and by sampling at
intervals in declination with a beamwidth of
(FWHM) it is possible to build up a fully sampled
two-dimensional map of the sky at each frequency [82]. Initially, observations were concentrated on the strip of sky
at declination
where the low frequency surveys of Haslam
et al.
(408 MHz) [55] and Reich and Reich (1420 MHz) [83] indicate a minimum in Galactic foreground emission.
Analysis of the data at declination
has been made and reported in Hancock
et al.
(1994) [52
]. Results from the Dec.
data scans at 10 and 15 GHz have recently been reported in
Gutierrez
et al.
[51] and are consistent with the Dec.
data. A level of
K was found in a high Galactic latitude region at Dec.
at 15 GHz. The COBE data was used in Bunn
et al.
(1996) to make a prediction for the Tenerife data. The
comparison between this prediction and the Tenerife 15 GHz
data is shown in Figure
12, and it is seen that there is very good agreement with the main
features in the COBE scan. This is evidence for features that are
constant in amplitude over a frequency range of 15 GHz to
90 GHz and is a very strong candidate for a real CMB
anisotropy.
The Tenerife programme is continuing, with the objective of
mapping some 4000 square degrees of sky at 10, 15 and
33 GHz. In conjunction with the COBE four-year data set,
these experiments will continue to offer a useful source of
large-scale CMB anisotropy measurements and hence to directly
probe cosmological theories. In terms of power spectrum results,
a revised estimate of the fluctuation amplitude for
values near
has been constructed from the Dec
data, making an allowance for an atmospheric contribution
(Hancock
et al.
1997 [53]) that was not subtracted in Hancock
et al.
[52]. This is used below in comparison with theoretical curves.
Preliminary analysis of the full 15 GHz data set (Dec.
to
) has been made and will be presented in a future paper. For an
assumed value of
n
=1 a full two dimensional likelihood analysis gives
K.
![]() |
The Cosmic Microwave Background
Aled W. Jones and Anthony N. Lasenby http://www.livingreviews.org/lrr-1998-11 © Max-Planck-Gesellschaft. ISSN 1433-8351 Problems/Comments to livrev@aei-potsdam.mpg.de |