The Impact of Polarized Extragalactic Radio Sources on the Detection of CMB Anisotropies in Polarization

Table 1

Median, mean, and ⟨Π²⟩^1/2 of the fractional polarization for flat-spectrum sources in the almost complete subsample of the AT20G surveys at different observational frequencies and flux ranges. 𝑁_tot refers to the total number of objects in the corresponding flux range; 𝑁_multi to the number of objects with 5- and 8-GHz measurements; 𝑁_fl to the number of flat-spectrum sources; 𝑁_det to the number of flat-spectrum sources with polarization detection.

𝑆(Jy)	𝑁tot	𝑁multi	𝑁fl	𝑁det	Πmed	⟨Π⟩	⟨Π^2⟩^1/2
	20 GHz
≥1.0	130	114	110	85	2.05	2.82	3.72
≥0.5	315	287	264	188	2.01	2.76	3.84
[0.5, 1)	185	173	154	103	1.92	2.72	3.92
	8.6 GHz
≥1.0			110	87	2.00	2.52	3.00
≥0.5			264	180	1.76	2.34	2.85
[0.5, 1)			154	93	1.54	2.21	2.73
	4.8 GHz
≥1.0			110	93	1.90	2.31	2.71
≥0.5			264	186	1.71	2.25	2.69
[0.5,1)			154	93	1.59	2.20	2.68