Fig.3 shows some CMB power-spectrum results (adapted from Rocha (1997)). The apparent smooth delineation of the the Doppler peak is perhaps a little misleading as by chance there is little overlap in -coverage of the experiments plotted; when bolometric measurements are included the picture becomes a little more obscure! It appears clear, however, that the high power measured by Saskatoon combined with the lower power measured by CAT points to the existence of a real peak in the power spectrum.
Figure 3: CMB power-spectrum results from several experiments. From left to right: COBE; Tenerife; South Pole; five Saskatoon points; two CAT points (the new CAT2 data (Baker (1997)) have been added to the previous CAT1 results); Australia Telescope; Ryle Telescope.
This plot includes one new point, from the Ryle Telescope (RT), at . This is from observations of the Lynx 2 field, which has been the subject of several long integrations on different radio telescopes, including the VLA (Windhorst et al. (1993)). This field was observed at 15.2 GHz with the RT compact array on 54 occasions between 1994 February and 1997 April, resulting in a map with a noise level of and a resolution of arcsec. After removal of two point sources the visibility data were analysed for excess power using the same procedures as used for CAT data (Scott et al. (1996)). This results in a preliminary limit for flat-band power in the interval of (67% confidence), further confirming the result that CMB fluctuations on arcminute scales have an order of magnitude less power than on degree scales.