The figure (and this accompanying table) displays the current status of CMB anisotropy observations. This is a representation of the results from COBE, together with a wide range of ground- and balloon-based experiments which have operated in the last few years. Plotted are the quadrupole amplitudes for a flat (unprocessed scale-invariant spectrum of primordial perturbations, ie, a horizontal line) anisotropy spectrum that would give the observed results for each experiment. In other words each point is the normalization of a flat spectrum derived from individual experiments. The dotted line shows the best fit horizontal line for the COBE data alone.
The vertical error bars represent estimates of 68% CL, while the upper limits are at 95% CL. Horizontal bars indicate the range of $\ell$ values sampled. To be explicit, specific choices have to be made in order to present all the data in this way; here the values of Qflat have all been symmetrised, and the points are plotted at the window function maxima.
The curve indicates the expected spectrum for a standard CDM model (Omega_0 = 1, Omega_B =0.05, h =0.5), although true comparison with models should involve convolution of this curve with each experimental filter function. References for this figure can be found here.
l0 l1 l2 Q dQ -dlogl +dlogl Label Notes
3.16 2 5 18.5 3.1 0.199 0.199 COBE 4-yr (Hinshaw et al. 1994)
7.75 6 10 16.2 2.1 0.111 0.111 COBE
14.83 11 20 20.0 2.1 0.130 0.130 COBE
29.0 21 40 0.5 25 0.140 0.140 COBE
9 3 29 19 5 0.491 0.494 FIRS (Ganga et al. 1993)
20 13 30 21.5 6 0.187 0.176 Ten. (Gutierrez et al. 1997)
50 21 99 14.8 2.7 0.377 0.297 PyV (Python V - Coble et al. 1999)
74 35 130 16.8 5.2 0.325 0.245 PyV (Python V - Coble et al. 1999)
108 67 157 20.0 5.6 0.207 0.162 PyV (Python V - Coble et al. 1999)
140 99 185 17.4 8.0 0.150 0.121 PyV (Python V - Coble et al. 1999)
172 132 215 34.9 7.8 0.115 0.097 PyV (Python V - Coble et al. 1999)
203 164 244 63.2 12.0 0.093 0.080 PyV (Python V - Coble et al. 1999)
233 195 273 46.5 46.5 0.077 0.069 PyV (Python V - Coble et al. 1999)
264 227 303 0.5 59.4 0.066 0.060 PyV (Python V - Coble et al. 1999)
58 28 97 31 9 0.316 0.223 BAM (Q_flat fit)
66 32 109 13 9 0.314 0.218 SP91 (Schuster et al. 1993)
68 32 109 25.9 6 0.314 0.218 SP94 (Gundersen et al. 1994)
80 59 100 30.0 5.5 0.132 0.097 QMAP (de Oliveira-Costa etal 1998)
126 99 153 37.8 6.2 0.105 0.084 QMAP (de Oliveira-Costa etal 1998)
111 79 143 33.6 4.9 0.148 0.110 QMAP (de Oliveira-Costa etal 1998)
87 49 105 39.2 9.2 0.249 0.082 Pyth. (95 Platt et al. 1997)
170 120 239 43.2 10.5 0.151 0.148 Pyth. (high l)
107 53 180 25.2 5.5 0.305 0.226 ARGO (Hercules, deBern. etal 95)
109 53 180 26.9 4.6 0.305 0.226 ARGO (Aries & Taurus, Masi etal 96)
125 60 205 61 27 0.319 0.215 IAB (Piccirillio & Calisse 93)
84 39 130 23.9 8.5 0.333 0.190 MSAM (MSAM 1 - Wilson et al. 1999)
201 131 283 32.3 6.0 0.186 0.148 MSAM (MSAM 1)
407 284 453 30.7 4.5 0.156 0.046 MSAM (MSAM 1)
158 78 263 31.9 5.0 0.307 0.221 MAX (combined - Tanaka priv. comm.)
90 52 131 32.6 6.2 0.238 0.163 Sask. (95, Netterfield et al.)
152 118 205 44.9 7.6 0.110 0.130 Sask.
232 189 274 55.5 9.7 0.089 0.072 Sask.
273 243 319 56.2 10.6 0.051 0.068 Sask.
338 304 401 41.6 16.2 0.046 0.074 Sask.
422 339 483 31.2 4.0 0.291 0.173 CAT (low-l, Scott et al. 1996)
615 546 722 30.1 6.4 0.180 0.127 CAT (high-l, Scott etal, Baker 1997)
539 297 825 0.5 97 0.259 0.185 WD (White Dish, Tucker 94, Ratra 98)
589 361 756 36.5 4.8 0.213 0.108 Ring (OVRO, Leitch et al. 1998)
1750 1100 2750 1.0 29 0.202 0.196 OVRO (Readhead et al. 1989)
2400 1330 3670 0.5 28 0.256 0.184 SuZIE (Church/Ganga et al. 1997)
4520 3500 5780 1.0 23.6 0.111 0.107 ATCA (Subrahmanyan et al. 1993, 1997)
6300 4300 8300 0.5 20 0.166 0.120 RT (Ryle, Jones, PPEUC 1997)
7500 5500 9500 1.0 53 0.100 0.100 VLA (Partridge et al. 1997)
13081 0 0 0.5 152 0.200 0.200 SCUBA (Scuba - UBC)
80 59 100 30.0 5.5 0.132 0.097 QMAP (de Oliveira-Costa etal 1998)
126 99 153 37.8 6.2 0.105 0.084 QMAP (de Oliveira-Costa etal 1998)
111 79 143 33.6 4.9 0.148 0.110 QMAP (de Oliveira-Costa etal 1998)