Related papers: Thoughts on galactic magnetism
Earlier Enqvist and Olesen have shown that formation of ferromagnetic planar walls in vacuum at GUT scales in comoving plasmas may generate a large scale magnetic field of $B_{now}\simeq{10^{-14}G}$. In this paper we show that starting from…
We performed cosmological, magneto-hydrodynamical simulations to follow the evolution of magnetic fields in galaxy clusters, exploring the possibility that the origin of the magnetic seed fields are galactic outflows during the star-burst…
Astrophysical processes can contribute to magnetic fields within cosmic voids either through magnetized outflows from the astrophysical large-scale structure or through superposition of dipolar contributions from individual galaxies. Such…
The Galactic magnetic field plays an important role in the evolution of the Galaxy, but its small-scale behaviour is still poorly known. It is also unknown whether it permeates the halo of the Galaxy or not. By using observations of pulsars…
The existence of magnetic fields associated with the intracluster medium in clusters of galaxies is now well established through different methods of analysis. The most detailed evidence for the presence of cluster magnetic fields comes…
The nature and origin of turbulence and magnetic fields in the intergalactic space are important problems that are yet to be understood. We propose a scenario in which turbulent flow motions are induced via the cascade of the vorticity…
Magnetic fields are found in many astrophysical objects, ranging from galaxy clusters to the interstellar medium of galaxies and neutron stars. Strong magnetic fields are also observed in massive stars, but it is still unclear how they are…
Magnetic fields are observed beyond the peripheries of optically detected galactic discs, while numerical models of their origin and the typical magnitudes are still absent. Previously, studies of galactic dynamo have avoided considering…
Although indirect evidence for the presence of magnetic fields in high-mass stars is regularly reported in the literature, the detection of these fields remains an extremely challenging observational problem. We review the recent…
Constraining dynamo theories of magnetic field origin by observation is indispensable but challenging, in part because the basic quantities measured by observers and predicted by modelers are different. We clarify these differences and…
The presence of a strong magnetic field is a feature common to a significant fraction of degenerate stars, yet little is understood about field origin and evolution. New observational constraints from volume-limited surveys point to a more…
We seek the conditions for a {\it steady} mean field galactic dynamo. The parameter set is reduced to those appearing in the $\alpha^2$ and $\alpha/\omega$ dynamo, namely velocity amplitudes, and the ratio of sub-scale helicity to…
We search for observational signatures of magnetic helicity in data from all-sky radio polarization surveys of the Milky Way Galaxy. Such a detection would help confirm the dynamo origin of the field and may provide new observational…
We use a simple analytic model for the evolution of currents in superconducting strings to estimate the strength of the `seed' magnetic fields generated by these strings. This model is an extension of the evolution model of Martins and…
Spontaneous breaking of Lorentz invariance may take place in string theories, possibly endowing the photon with a mass. This leads to the breaking of the conformal symmetry of the electromagnetic action allowing for the generation within…
Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the…
Multi-frequency radio polarimetry of the diffuse Galactic synchrotron background gives new viewpoints on the Galactic magnetic field. Rotation measure maps reveal magnetic structures on arcminute to degree scales, such as a ring in…
Arguably the main challenge of galactic magnetism studies is to explain how the interstellar medium of galaxies reaches energetic equipartition despite the extremely weak cosmic primordial magnetic fields that are originally predicted to…
Total magnetic fields in spiral galaxies, as observed through their total synchrotron emission, are strongest (up to \simeq 30\mu G) in the spiral arms. The degree of radio polarization is low; the field in the arms must be mostly turbulent…
Magnetic fields have been detected on stars across the H-R diagram and substellar objects either directly by their effect on the formation of spectral lines, or through the activity phenomena they power which can be observed across a large…