The White Mountain Collaboration made measurements of the CMB temperature at five frequencies from 2.5 to 90 GHz.
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(see Smoot, G.F. et al. 1983, Phys.Rev.Lett. 51, 1099 ADS, and Smoot, G.F. et al. 1985, Ap.J., 291, L23 ADS)
Frequency (GHz) |
System bandwidth (GHz) |
Antenna Half-power beam width (deg) |
System noise (K/Hz1/2) |
Laboratory (Ref) |
---|---|---|---|---|
2.5 | 0.160 | 12.5 | 0.2 | Milano (1) |
4.75 | 0.160 | 12.5 | 0.1 | Bologna (2) |
9.4(*) | 1 | 12.6 | 0.1 | Haverford (3,4) |
10.0 | 0.910 | 12.5 | 0.05 | Berkeley (5) |
33.0 | 1 | 7.5 | 0.08 | Berkeley (6) |
90.0 | 2 | 7.5 | 0.1 | Berkeley (7) |
(*) entirely dedicated to study the atmospheric emission
(1) Sironi G. and Bonelli G., 1986, ApJ, 311, 418
(2) Mandolesi N. et al 1986, Ap.J. 310, 561
(3) Partridge R.B. et al., 1984, Phys.Rev. D, 29, 2683
(4) Danese L. and Partridge R.B., 1989, ApJ 342, 604
(5) Kogut A. et al., 1988, ApJ, 325, 1
(6) De Amici G. et al., 1985, ApJ , 298, 210
(7) Witebsky C. et al., 1986, ApJ, 310, 145
Frequency (GHz) |
Eccosorb (o) (mK) |
Windows + gas (mK) |
Dewar walls (mK) |
Reflected signals (mK) |
Total (mK) |
---|---|---|---|---|---|
2.5 | 3716±4 | 4±2 | 1209±210 (a) 1458±120 (b) |
70±25 (a) 340±50 (b) |
4999±212 (a) 5518±130 (b) |
4.75 | 3663±4 | 5±2 | 8±7 | 40±30 (a) 6±4 (b) |
3716±31 (a) 3682±10 (b) |
10 | 3541±4 | 5±2 | 9±5 | 7±4 | 3562±10 |
33 | 3039±4 | 4±2 | 5±5 | 20±6 | 3068±9 |
90 | 2020±4 | 18±3 | 10±10 | 35±35 | 2083±37 |
(o) Eccosorb/Liquid Helium physical temperature 3776±4 mK,
(a) 1982 value,
(b) 1983 value
Frequency (GHz) |
TA,load (mK) |
ΔT (sky-load) (mK) |
ΔToffset (mK) |
Tground (mK) |
Tatmosphere (mK) |
TGalaxy (mK) |
Year |
---|---|---|---|---|---|---|---|
2.5 | 4999±212 5518±130 |
-1401±100 -1557±58 |
(a) (a) |
12±10 6±10 |
950±50 950±50 |
148±30 200±30 |
1982 1983 |
4.75 | 3716±31 3682±10 |
940±80 -45±13 |
960±160 0±20 |
30±10 20±20 |
1000±100 997±70 |
40±30 35±25 |
1982 1983 |
9.4 | -- -- |
-- -- |
-- -- |
30±10 8±5 |
1030±30 103±30 |
<30±10 <10±5 |
1982 1983 |
10 | 3562±10 | 57±4 43±7 |
0±40 0±30 |
0±3 0±3 |
930±160 1200±130 |
3±3 4±2 |
1982 1983 |
33 | 3068±9 | 3860±40 3540±30 |
-100±50 -30±30 |
1±1 1±1 |
4850±140 4530±90 |
1±1 1±1 |
1982 1983 |
90 | 2083±17 | 11340±60 8780±37 |
0±300 10±9 |
1±1 1±1 |
12600±590 9870±90 |
0±1 0±1 |
1982 1983 |
(a)included in TA,load
Frequency (GHz) |
Number of observations |
CMB antenna temperature (K) |
CMB thermodynamic temperature (K) |
Combined 1982 and 1983 results (K) |
---|---|---|---|---|
2.5 | 6 18 |
2.48±0.14 2.81±0.07 |
2.54±0.14 2.87±0.07 |
2.79±0.15 Ref.1 |
4.75 | 5 38 |
2.63±0.21 2.59±0.08 |
2.73±0.22 2.70±0.07 |
2.70±0.07 Ref.2 |
10 | 82 59 |
2.43±0.12 2.40±0.14 |
2.66±0.12 2.63±0.14 |
2.65±0.09 Ref.5 |
33 | 21 32 |
2.10±0.20 2.09±0.13 |
2.82±0.21 2.81±0.14 |
2.81±0.12 Ref.6 |
90 | 29 49 |
1.00±0.57 0.99±0.09 |
2.58±0.79 2.57±0.12 |
2.57±0.12 Ref.7 |
For Columns 2-4, the first row is for 1982 data and the second row is for 1983 data.