PolAME · Polarimetry of Anomalous Microwave Emission: Implication for B-mode Polarization Detection and Galactic Science

Polarimetry of Anomalous Microwave Emission: Implication for B-mode Polarization Detection and Galactic Science

The main goal of the PolAME project is to characterise the level of polarisation (i.e. the geometrical orientation of the oscillations of the radiation) of the Anomalous Microwave Emission (AME) observed at radio frequencies in the frequency range [10-100] Gigahertz (GHz). The AME is an emission that has been discovered about 20 years ago which is very likely produced by very small dust grain particles pervading the interstellar medium. The polarisation properties of the AME have to be characterised and understood completely for one willing to remove Galactic foregrounds in order to analyse the polarisation of the CMB for cosmology. This project is therefore important for the Galactic community as well as for the Cosmology community. The PolAME project uses the QUIJOTE-CMB experiment and its Multi-Frequency Instrument (MFI) for measuring the degree of polarisation of the AME in the domain range [10- 30] GHz toward a series of Molecular cloud regions. Molecular clouds are regions denser than the diffuse interstellar medium and they are regions where most of the star formation occurs in our Galaxy. They cover a large fraction of the full sky therefore it is important to understand the properties of the AME in these regions and not only in the diffuse interstellar medium of our Galaxy. The main objective of PolAME is to combine the QUIJOTE data with the data from the WMAP and Planck satellites that are publicly available, as well as with other publicly available data to isolate the AME components and study their properties in intensity and in polarisation. During the project we produced intensity and polarisation maps of the sample of 8 molecular clouds initially identified for the project. We added two more regions of interest to the sample. The analysis of this two more regions has been a test bed for the analysis method and allowed us to test the modelling of the various Galactic components that has to be done to isolate the AME components. Once this was done we put constraints on the level of polarisation of the AME component in these two regions. The initial sample of molecular clouds take advantage of this work and is presently under study. The new constraints put on the level of polarisation of AME in the molecular clouds studied until now enlarge the statistics available in the literature from similar studies on other regions. Our results also show the importance of the QUIJOTE-MFI which, currently, is the only experiment probing the sky in intensity and polarisation in the frequency range [10-20] GHz, for getting accurate measurements of the AME components in this frequency range.

Data: CORDIS, © European Union