Journal ArticleDOI
Extragalactic magnetic fields
Reads0
Chats0
TLDR
In this paper, the observational methods for detecting and measuring extragalactic magnetic fields are discussed, along with some new indirect methods which could be used for inferring field strengths at large redshifts which are otherwise beyond the reach of direct measurement.Abstract:
The observational methods for detecting and measuring extragalactic magnetic fields are discussed, along with some new indirect methods which could be used for inferring field strengths at large redshifts which are otherwise beyond the reach of direct measurement. Various cosmological seed field generation mechanisms are reviewed, which could generate seed fields for the subsequently formed galaxies. The question of whether the original seed fields were produced in galaxies, or the pre-recombination early Universe must await a clearer picture of how the first stars and galaxies formed.read more
Citations
More filters
Journal ArticleDOI
Astrophysical magnetic fields and nonlinear dynamo theory
TL;DR: The current understanding of astrophysical magnetic fields is reviewed in this paper, focusing on their generation and maintenance by turbulence, where analytical and numerical results are discussed both for small scale dynamos, which are completely isotropic, and for large scale dynamo, where some form of parity breaking is crucial.
Journal ArticleDOI
Galactic Magnetism: Recent developments and perspectives
TL;DR: In this article, it is argued that a turbulent hydromagnetic dynamo of some kind and an inverse cascade of magnetic energy gives the most plausible explanation for the regular galactic magnetic fields.
Journal ArticleDOI
Evidence for Strong Extragalactic Magnetic Fields from Fermi Observations of TeV Blazars
Andrii Neronov,Ievgen Vovk +1 more
TL;DR: A lower bound B ≥ 3 × 10−16 gauss on the strength of intergalactic magnetic fields is reported, which stems from the nonobservation of GeV gamma-ray emission from electromagnetic cascade initiated by tera–electron volt gamma rays inintergalactic medium.
Journal ArticleDOI
Magnetic Fields in the Early Universe
Dario Grasso,H. Rubinstein +1 more
TL;DR: In this paper, the authors discuss magnetic fields in the early universe, their origin, their possible detection, and their limits and values today and at early times, and discuss the possible detection of magnetic fields.
Journal ArticleDOI
Origin of galactic and extragalactic magnetic fields
TL;DR: A variety of observations suggest that magnetic fields are present in all galaxies and galaxy clusters as mentioned in this paper, but fundamental questions concerning the nature of the dynamo as well as the origin of the seed fields necessary to prime it remain unclear.
References
More filters
Journal ArticleDOI
Statistical-Mechanical Theory of Irreversible Processes : I. General Theory and Simple Applications to Magnetic and Conduction Problems
TL;DR: In this paper, a general type of fluctuation-dissipation theorem is discussed to show that the physical quantities such as complex susceptibility of magnetic or electric polarization and complex conductivity for electric conduction are rigorously expressed in terms of timefluctuation of dynamical variables associated with such irreversible processes.
Journal ArticleDOI
Topology of cosmic domains and strings
TL;DR: In this article, the possible domain structures which can arise in the universe in a spontaneously broken gauge theory are studied, and it is shown that the formation of domain wall, strings or monopoles depends on the homotopy groups of the manifold of degenerate vacua.
Journal ArticleDOI
End to the cosmic ray spectrum
TL;DR: The primary cosmic-ray spectrum has been measured up to an energy of $10^{20}$ eV, and several groups have described projects under development or in mind to investigate the spectrum further, into the energy range of 10^{21}-10^{22} eV as mentioned in this paper.
Journal ArticleDOI
The Morphology of Extragalactic Radio Sources of High and Low Luminosity
B. L. Fanaroff,J. M. Riley +1 more
Topology of Cosmic Domains and Strings
TL;DR: In this article, the possible domain structures which can arise in the universe in a spontaneously broken gauge theory are studied, and it is shown that the formation of domain wall, strings or monopoles depends on the homotopy groups of the manifold of degenerate vacua.