相关论文: On the amplification of magnetic fields in cosmic …
Recent numerical studies suggest that magnetic fields play an important role in primordial star formation in the early universe. However, the detailed evolution of the magnetic field in the collapse phase still has uncertainties because of…
A fully three-dimensional (3D) magnetohydrodynamical (MHD) model is applied to simulate the evolution of the large-scale magnetic field in cluster galaxies interacting with the intra-cluster medium (ICM). As the model input we use a time…
Turbulent dynamo field amplification has often been invoked to explain the strong field strengths in thin rims in supernova shocks ($\sim 100 \, \mu$G) and in radio relics in galaxy clusters ($\sim \mu$G). We present high resolution MHD…
Filaments are ubiquitous in the universe. Recent observations have revealed that stars and star clusters form preferentially along dense filaments. Understanding the formation and properties of filaments is therefore a crucial step in…
We present a model for the seeding and evolution of magnetic fields in protogalaxies. Supernova (SN) explosions during the assembly of a protogalaxy provide magnetic seed fields, which are subsequently amplified by compression, shear flows…
Observations of non-thermal emission from several supernova remnants suggest that magnetic fields close to the blastwave are much stronger than would be naively expected from simple shock compression of the field permeating the interstellar…
We study the influence of initial conditions on the magnetic field amplification during the collapse of a magnetised gas cloud. We focus on the dependence of the growth and saturation level of the dynamo generated field on the turbulent…
The universe is magnetized on all scales probed so far. On the largest scales, galaxies and galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten kpc. Recent observational evidence suggests that even the…
Galaxy clusters host a hot, diffuse plasma with poorly understood viscosity and magnetic field amplification. Astrophysical plasmas are often modeled with magnetohydrodynamics (MHD), but low collision rates in environments like the…
The turbulence driven by gravitational instabilities (GIs) can amplify magnetic fields in massive gaseous disks. This GI dynamo may appear in young circumstellar disks, whose weak ionization challenges other amplification routes, as well as…
In paper I, we obtained an equation for the evolution of density inhomogeneities in a radiation dominated universe when they are affected by magnetic fields. In this second paper we apply this equation to the case in which the subjacent…
The small-scale dynamo provides a highly efficient mechanism for the conversion of turbulent into magnetic energy. In astrophysical environments, such turbulence often occurs at high Mach numbers, implying steep slopes in the turbulent…
We discuss how gravitational waves could amplify seed magnetic fields to strengths capable of supporting the galactic dynamo. We consider the interaction of a weak magnetic field with gravity wave distortions in almost FRW cosmologies and…
Various observations of magnetic fields in the Intra-Cluster Medium (ICM), most of the time restricted to cluster cores, point towards field strength of the order of a few microG (synchrotron radiation from radio relics and radio halos,…
Magnetic fields are ubiquitous in the Universe. Recently, cosmological simulations of galaxies have successfully begun to incorporate magnetic fields and their evolution in galaxies and their haloes. However, so far they have mostly focused…
Magnetic fields permeate the Universe on all scales and play a key role during star formation. We study the evolution of magnetic fields around a massive metal-free (Population III) star at $z \sim 15$ during the growth of its HII region…
Primordial magnetic fields (PMFs) generated in the early Universe may leave observable imprints in the present-day large-scale structure. However, it remains unclear on which spatial scales primordial signatures can survive the nonlinear…
Magnetic fields are considered as a vital ingredient of contemporary star formation, and may have been important during the formation of the first stars in the presence of an efficient amplification mechanism. Initial seed fields are…
Basically the only existing theories for the creation of a magnetic field B in the Universe are the creation of a seed field of order 10^{-20} G in spiral galaxy which is subsequently supposedly amplified up to the observed 10^{-6} -…
The magnetic fields of spiral galaxies are so strong that they cannot be primordial. Their typical values are over one billion times higher than any value predicted for the early Universe. Explaining this immense growth and incorporating it…