Faraday rotation, stochastic magnetic fields and CMB maps
نویسندگان
چکیده
The highand low-frequency descriptions of the pre-decoupling plasma are deduced from the Vlasov-Landau treatment generalized to curved space-times and in the presence of the relativistic fluctuations of the geometry. It is demonstrated that the interplay between one-fluid and two-fluid treatments is mandatory for a complete and reliable calculation of the polarization observables. The Einstein-Boltzmann hierarchy is generalized to handle the dispersive propagation of the electromagnetic disturbances in the pre-decoupling plasma. Given the improved physical and numerical framework, the polarization observables are computed within the magnetized ΛCDM paradigm (mΛCDM). In particular, the Faraday-induced B-mode is consistently estimated by taking into account the effects of the magnetic fields on the initial conditions of the Boltzmann hierarchy, on the dynamical equations and on the dispersion relations. The complete calculations of the angular power spectra constitutes the first step for the derivation of magnetized maps of the CMB temperature and polarization which are here obtained for the first time and within the minimal mΛCDM model. The obtained results set the ground for direct experimental scrutiny of large-scale magnetism via the low and high frequency instruments of the Planck explorer satellite. Electronic address: [email protected] Electronic address: [email protected] 1 Plasma hierarchies and plasma descriptions Prior to matter-radiation equality and throughout decoupling the number of charge carriers present within the Debye sphere is, overall, inversely proportional to the baryonic concentration. The corresponding (dimensionless) plasma parameter [1, 2, 3] is O(10−7) and, more specifically gplasma = 1 VDn0xe = 24e √ ζ(3) π √ xeηb0 = 2.308× 10 √ xe ( h0Ωb0 0.02273 )1/2 , VD = 4 3 πλD, λD = √
منابع مشابه
A Faraday Rotation Template for the Galactic Sky
Using a set of compilations of measurements for extragalactic radio sources we construct all-sky maps of the Faraday Rotation produced by the Galactic magnetic field. In order to generate the maps we treat the radio source positions as a kind of ”mask” and construct combinations of spherical harmonic modes that are orthogonal on the masked sky. As long as relatively small multipoles are used th...
متن کاملFaraday Rotation Effect of Intracluster Magnetic Field on Cosmic Microwave Background Polarization
The observed magnetic field of microgauss strength in clusters of galaxies should induce the Faraday rotation effect on the linearly polarized cosmic microwave background (CMB) radiation when the CMB radiation propagates through a cluster at low redshift. The Faraday rotation arises from combined contributions of the magnetic field strength, the electron density, the cluster size, and the chara...
متن کاملPlanck 2015 results - XIX. Constraints on primordial magnetic fields
We compute and investigate four types of imprint of a stochastic background of primordial magnetic fields (PMFs) on the cosmic microwave background (CMB) anisotropies: the impact of PMFs on the CMB temperature and polarization spectra, which is related to their contribution to cosmological perturbations; the effect on CMB polarization induced by Faraday rotation; the impact of PMFs on the ioniz...
متن کاملFaraday Rotation of the CMB Polarization and Primordial Magnetic Field Properties
Measurements of the Faraday rotation of the CMBR polarization could provide an evidence for the existence of primordial magnetic fields. The Faraday rotation could also allow to study some properties of the latter. In this paper, we calculate angular dependence of the Faraday rotation correlator for different assumptions about the spectral index and correlation length of the magnetic field. We ...
متن کاملAntisymmetry in the Faraday Rotation Sky Caused by a Nearby Magnetized Bubble
Rotation measures of pulsars and extragalactic point sources have been known to reveal largescale antisymmetries in the Faraday rotation sky with respect to the Galactic plane and halo that have been interpreted as signatures of the mean magnetic field in the Galactic halo. We describe Faraday rotation measurements of the diffuse Galactic polarized radio emission over a large region in the nort...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008