Probing Primordial Magnetic Fields with the 21cm Fluctuations

Abstract

Primordial magnetic fields possibly generated in the very early universe are one of the candidates for the origin of magnetic fields observed in many galaxies and galaxy clusters. After recombination, the dissipation process of the primordial magnetic fields increases the baryon temperature. The Lorentz force acts on the residual ions and electrons to generate density fluctuations. These effects are imprinted on the cosmic microwave background (CMB) brightness temperature fluctuations produced by the neutral hydrogen 21cm line. We calculate the angular power spectrum of brightness temperature fluctuations for the model with the primordial magnetic fields of a several nano Gauss strength and a power-law spectrum. It is found that the overall amplitude and the shape of the brightness temperature fluctuations depend on the strength and the spectral index of the primordial magnetic fields. Therefore, it is expected that the observations of the CMB brightness temperature fluctuations give us a strong constraint on the primordial magnetic fields.

12 pages, submitted to MNRAS

References in corpus (2)

• The CMBR fluctuations from HI perturbations prior to reionization
• CMB anisotropies from primordial inhomogeneous magnetic fields

Cited by in corpus (5)

• Reionization - A probe for the stellar population and the physics of the early universe
• Effects of primordial chemistry on the cosmic microwave background
• Dark stars: Implications and constraints from cosmic reionization and extragalactic background radiation
• The cross-correlation of the CMB polarisation and the 21-cm line fluctuations from cosmic reionisation
• Cosmic 21-cm Fluctuations as a Probe of Fundamental Physics