Observations of the Polarisation of the Anomalous Microwave Emission: A Review

Table 1

Summary of the current constraints on the fractional polarisation (Π) of the AME both for individual Galactic objects and for large-scale (diffuse) measurements. Columns 1 to 3 indicate the region, the experiment used for this particular constraint, and the angular resolution, respectively. The following four columns indicate the constraints on the fractional polarisation (Π), separated according to the frequency band for an easier comparison. When quoting upper limits, the 95% confidence level is used. Last column provides the relevant references.

Name	Experiment	Resolution	∏ (9–11 GHz); [%]	∏ (22 GHz); [%]	∏ (30–33 GHz); [%]	∏ (40 GHz); [%]	References
			Galactic AME regions
G159.6-18.5	COSMOSOMAS	1°	3.4^+1.5−1.9				[65]
”	WMAP-7	1°		<1.01	<1.79	<2.69	[48]
”	WMAP-7	1°		<1.4	<1.9	<4.7	[49]
𝜌 Ophiuchi	CBI	~9′			<3.2		[24]
”	WMAP-7	1°		<1.7	<1.6	<2.6	[49]
LDN1622	GBT	~1.3′	<2.7				[10]
”	WMAP-7	1°		<2.6	<4.8	<8.3	This work
Pleiades	WMAP-7	1°		<12.2	<32.0	<95.8	[21], this work
LPH96	CBI	~9′			<10		[23]
”	WMAP-7	1°		<1.3	<2.5	<7.4	This work
Helix	CBI	~9′			<8		[66]
			Diffuse Galactic AME
All sky	WMAP-3	1°		<1	<1	<1	[67]
All sky	WMAP-5	1°		<5			[16]