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Tracing Primordial Magnetic Fields with 21 cm Line Observations

Departamento de Física Fundamental, Universidad de Salamanca, Plaza de la Merced s/n, 37008 Salamanca, Spain
Galaxies 2019, 7(1), 37;
Received: 23 October 2018 / Revised: 26 February 2019 / Accepted: 6 March 2019 / Published: 13 March 2019
(This article belongs to the Special Issue The Power of Faraday Tomography)
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Magnetic fields are observed on a large range of scales in the universe. Up until recently, the evidence always pointed to magnetic fields associated with some kind of structure, from planets to clusters of galaxies. Blazar observations have been used to posit the first evidence of truly cosmological magnetic fields or void magnetic fields. A cosmological magnetic field generated in the very early universe before recombination has implications for the cosmic microwave background (CMB), large scale structure as well as the 21 cm line signal. In particular, the Lorentz term causes a change in the linear matter power spectrum. Its implication on the 21 cm line signal was the focus of our recent simulations which will be summarised here. Modelling the cosmological magnetic field as a gaussian random field numerical solutions were found for magnetic fields with present day amplitudes of 5 nG and negative spectral indices which are within the range of observational constraints imposed by the cosmic microwave background (CMB). View Full-Text
Keywords: cosmological magnetic fields; 21 cm line observations; large scale structure cosmological magnetic fields; 21 cm line observations; large scale structure

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Kunze, K.E. Tracing Primordial Magnetic Fields with 21 cm Line Observations. Galaxies 2019, 7, 37.

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