Related papers: Protogalactic evolution and magnetic fields
Several lines of evidence suggest that protogalactic and galactic environments manage to grow magnetic field very rapidly. This makes the theoretical problem of achieving rapid growth of magnetic fields in such environments difficult.…
Isolated magnetic white dwarfs have field strengths ranging from kilogauss to gigagauss. However, the origin of the magnetic field has not been hitherto elucidated. Whether these fields are fossil, hence the remnants of original weak…
We propose a model of magnetic-field growth in galaxy clusters whereby the field is amplified by a factor of about 10^8 over a cosmologically short time of ~10^8 yr. Our model is based on the idea that the viscosity of the intracluster…
We study the generation of primordial magnetic fields, coherent over cosmologically interesting scales, by gravitational creation of charged scalar particles during the reheating period. We show that magnetic fields consistent with those…
The origin of magnetic fields in clusters of galaxies is still an unsolved problem, which is largely due to our poor understanding of initial seed magnetic fields. If the seed magnetic fields have primordial origins, it is likely that…
Are magnetic fields important in primordial star formation? Assuming that star formation occurs via an accretion disk that is turbulent, initially because of local gravitational instability, we calculate the disk structure for realistic…
We propose a primordial-origin model for the composite configurations of global magnetic fields in spiral galaxies. We show that uniform tilted magnetic field wound up into a rotating disk galaxy can evolve into composite magnetic…
Cosmological simulations of magnetic fields in galaxy clusters show that remarkable agreement between simulations and observations of Faraday rotation and radio haloes can be achieved assuming that seed fields of 10^{-9} G were present at…
We discuss the evolution of cosmological magnetic fields from the early universe to the present. We review different scenarios for magnetogenesis in the early universe and follow the subsequent evolution of these fields as the universe…
We investigate hydromagnetic turbulence of primordial magnetic fields using magnetohydrodynamics (MHD) in an expanding universe. We present the basic, covariant MHD equations, find solutions for MHD waves in the early universe, and…
It is shown that the standard cosmological model predicts {\it ab initio} generation of large-scale but very small-amplitude cosmic magnetic fields at the epoch of recombination of the primeval plasma. Matter velocities dominated by…
We investigate the build-up of the galactic dynamo and subsequently the origin of a magnetic driven outflow. We use a setup of an isolated disc galaxy with a realistic circum-galactic medium (CGM). We find good agreement of the galactic…
The origin and maintenance of large scale magnetic fields in the Universe is discussed. A popular idea is that cosmic batteries generate seed magnetic fields which were amplified by magnetic induction due to turbulent motions, at times…
We analyze the possibility of primordial magnetic field amplification by a stochastic large scale kinematic dynamo during reheating. We consider a charged scalar field minimally coupled to gravity. During inflation this field is assumed to…
We numerically investigate the generation of a magnetic field in a protostellar disc via an $\alpha \Omega$-dynamo and the resulting magnetohydrodynamic (MHD) driven outflows. We find that for small values of the dimensionless dynamo…
Magnetism is one of the four fundamental forces. However, the origin of magnetic fields in stars, galaxies and clusters is an open problem in astrophysics and fundamental physics. When and how were the first fields generated? Are…
Magnetic fields in nearby, star-forming galaxies reveal both large-scale patterns and small-scale structures. A large-scale field reversal may exist in the Milky Way but no such reversals have been observed so far in external galaxies. The…
Measuring the magnetic field in cosmic filaments reveals how the Universe is magnetised and the process that magnetised it. Using the Rotation Measures (RM) at 144-MHz from the LoTSS DR2 data, we analyse the rms of the RM extragalactic…
Large-scale intergalactic magnetic fields may contain a mixture of galactic and cosmogenic contributions, that can be probed via observations of $\gamma$-ray "echo" - a delayed emission from electromagnetic cascades initiated by the highest…
The origin of ultra-intense magnetic fields on magnetars is a mystery in modern astrophysics. We model the core collapse dynamics of massive progenitor stars with high surface magnetic fields in the theoretical framework of a self-similar…