The MIPOL Collaboration made measurements of CMB circular polarization at 33 GHz.
![]() |
Sironi G. et al. (1998): New Astronomy, 3, 1-13, ADS
Sironi G. et al. (1998) ASP Conf. Ser. 141, 116, ADS
Gervasi M. et al. (2000) SIF Conf. Proc. 68,165
Spiga D. et al. (2002): New Astronomy, 7, 125-134, ADS
Gervasi M. et al. (2002): SPIE, 4843, 336-347, ADS
Mainini R. et al. (2013) JCAP, 08, 033, arXiv: 1307.6090v2, ADS
Type | Quantity | Circular Polariz. | Linear Polariz. | Unit |
---|---|---|---|---|
Total power | Sensitivity ch. 1 | 1165.8±20.0 | 1220.3±20.8 | adu/K |
Sensitivity ch. 2 | 1474.0±25.4 | 1457.8±23.9 | adu/K | |
Stability ch. 1 | 8.0 10-9 | 4.3 10-9 | s-1 | |
Stability ch.2 | 6.4 10-9 | 4.4 10-9 | s-1 | |
Correlator | Sensitivity ch. 1 | (2.9±0.9) 105 | (3.0±0.9) 105 | adu/K |
Sensitivity ch. 2 | (2.9±0.9) 105 | (3.0±0.9) 105 | adu/K | |
Offset ch. 1 | -(0.36±0.04) 105 | (1.85±0.07) 105 | adu | |
Offset ch. 2 | -(1.79±0.08) 105 | -(1.06±0.06) 105 | adu | |
Stability ch. 1 | 4.3 10-9 | 4.0 10-9 | s-1 | |
Stability ch. 2 | 4.4 10-9 | 8.5 10-9 | s-1 |
Observations of CMB in Circular Polarization mode
Summary of results
An improved upper limit to the CMB circular polarization
at large angular scales
Mainini R. et al. (2013) JCAP, 08, 033, arXiv: 1307.6090v2, ADS
Linear mode full sample |
Circular mode full sample |
Circular mode sub sample(o) |
Unit | |
---|---|---|---|---|
Tch1atm | 9.55±0.21 | 7.91±0.04 | 8.45±0.04 | K |
Tch2atm | 7.25±0.26 | 8.70±0.05 | 9.49±0.06 | K |
Tch1sys | 83.6±1.4 | 82.9±1.4 | 75.36±0.05 | K |
Tch2sys | 89.7±1.5 | 84.1±1.5 | 76.05±0.07 | K |
(o) data collected between Julian days 40136 and 40137 when the observing conditions were particularly good
tan (χatm) = – (1.68±0.09) | Tatm = (0.087±0.002) K |
tan (χgr) = - (0.24±0.06) | Tgr = (0.006±0.046) K |
Pixel size | Number of pixels | <V> | σV | σVpix | σ<V>pix | Unit |
2° x 2° unbinned data | 518 | -(0.02±0.06) | 1.29 | -- | -- | mK |
8° x 8° | 64 | -(0.02±0.08) | 0.64 | 1.14 | 0.43 | mK |
12° x 12° | 32 | -(0.02±0.07) | 0.38 | 1.27 | 0.35 | mK |
24° x 24° | 9 | -(0.02±0.06) | 0.15 | 1.37 | 0.21 | mK |
Pixel size | f | μ=<V> σ=σV χ2 P |
Best fit χ2 P |
Simulations χ2 P |
8° x 8° | 5 | 6.04 0.70 | 3.90 0.44 | 9.95 0.92 |
12° x 12° | 1 | 1.96 0.76 | 0.79 0.55 | 2.81 0.83 |
2° x 2° | 55 | 46.60 0.20 | -- | -- |
f = degree of freedom, P = probability of the assumed Gaussian model
Method | Classical | Bayesian | Spherical harmonics |
---|---|---|---|
Pixel size | ΠVCMB | ΠVCMB | ΠVCMB |
8° x 8° | 5.0 10-4 | 4.0 10-4 | 4.3 10-4 <θ>=7.5° |
12° x 12° | 2.7 10-4 | 3.2 10-4 | 2.4 10-4 <θ>=10.6° |
24° x 24° | 0.7 10-4 | 2.1 10-4 | 2.7 10-4 <θ>=18.0° |