Secondary B-mode polarization from Faraday rotation in clusters and galaxies
|Titre||Secondary B-mode polarization from Faraday rotation in clusters and galaxies|
|Type de publication||Journal Article|
|Year of Publication||2008|
|Auteurs||Tashiro, H, Aghanim, N, Langer, M|
|Journal||Monthly Notices of the Royal Astronomical Society|
We revisit the polarization induced by Faraday rotation when cosmic microwave background photons traverse magnetized plasma. We compute the secondary B-mode angular power spectrum from Faraday rotation due to magnetic fields in galaxies and galaxy clusters with masses ranging from 10(11) to 10(16.5) M-circle dot. We investigate its dependence on the electron and the magnetic field profiles. Namely we consider both the beta-profile of electron density as well as an electron density distribution based on the Navarro-Frenk-White dark matter profile. We model the magnetic field structure in galaxies and clusters motivated by recent observations. We further account for its redshift evolution and we examine the importance of its coherence length. We find that the B-mode polarization from Faraday rotation depends on the normalization parameter C-l proportional to sigma(5)(8)-sigma(6)(8). At 30 GHz for sigma(8) = 0.8, the B modes from Faraday rotation range between 0.01 and 4 x 10(-3) mu K-2 at l = 10(4) in the case of a maximally coherent fields. For smaller coherence lengths, those amplitudes are smaller and they peak at higher multipoles.