Related papers: Numerical simulations of quiet Sun magnetic fields…
Cosmological and astrophysical observations indicate the presence of magnetic field over all scales. In order to explain these magnetic fields, it is assumed that there exists a seed magnetic field that gets amplified by dynamos. These seed…
The Biermann battery is a promising generation mechanism of a seed magnetic field in the universe. We propose a new driving mechanism for the Biermann battery in an inhomogeneous plasma with a beam component. An inhomogeneous electron flow…
In the quiet Sun, magnetic fields are usually observed as small-scale magnetic elements, `salt and pepper', covering the entire solar surface. By using 3D radiative MHD numerical simulations we demonstrate that these fields are a result of…
We investigate generation processes of magnetic fields around first stars. Since the first stars are expected to form anisotropic ionization fronts in the surrounding clumpy media, magnetic fields are generated by effects of radiation force…
The origin of the magnetic field in galaxies is an open question in astrophysics. Several mechanisms have been proposed related, in general, with the generation of small seed fields amplified by a dynamo mechanism. In general, these…
It is recently proposed that cosmic rays generate a seed magnetic field in the early universe. In this paper, we propose another generation mechanism of magnetic fields by cosmic rays, which is the Biermann battery driven by resistive…
The presence of magnetic field is crucial in the transport of energy through the solar atmosphere. Recent ground-based and space-borne observations of the quiet Sun have revealed that magnetic field accumulates at photospheric heights, via…
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 simulate the dynamics and the evolution of quiet Sun magnetic elements to produce a probability density function of the field strengths associated with such elements. The dynamics of the magnetic field are simulated through a numerical…
We propose a novel dust battery mechanism for generating seed magnetic fields in the early universe, in which charged dust grains are radiatively accelerated, inducing strong electric currents that subsequently generate magnetic fields. Our…
The quiet Sun photospheric plasma has a variety of magnetic field strengths going from zero to 1800 G. The empirical characterization of these field strengths requires a probability density function (PDF), i.e., a function P(B) describing…
Our aim is to characterize the effects of the local magnetic fields in quiet regions of stellar atmospheres. We compute magneto-hydrodynamic and purely hydrodynamic simulations of G2V, K0V and M2V star. The magnetic simulations are started…
The Sun is the only star where we can resolve the intricate magnetism that all convective stars harbor. Yet, more than 99% of its visible surface along the solar cycle (the so-called quiet Sun) is filled with a tangled, unresolved…
Khomenko et al. estimate the mean magnetic field strength of the quiet Sun to be 20 G. The figure is smaller than several existing estimates, and it comes from the comparison between observed Zeeman polarization signals and synthetic…
Various aspects of the magnetism of the quiet sun are reviewed. The suggestion that a small scale dynamo acting at granular scales generates what we call the quiet sun fields is studied in some detail. Although dynamo action has been proved…
We demonstrate that the Biermann battery mechanism for the creation of large scale magnetic fields can arise in a simple model protogalaxy. Analytic calculations and numerical simulations follow explicitly the generation of vorticity (and…
Origin of the magnetic field ubiquitous in the Universe is studied based on the Biermann mechanism, which is expected to work in the non-barotropic region. We perform a series of two-dimensional MHD simulations of the first generation…
We present a series of radiative MHD simulations addressing the origin and distribution of mixed polarity magnetic field in the solar photosphere. To this end we consider numerical simulations that cover the uppermost 2-6 Mm of the solar…
Magnetic fields are usually observed in the quiet Sun as small-scale elements that cover the entire solar surface (the `salt and pepper' patterns in line-of-sight magnetograms). By using 3D radiative MHD numerical simulations we find that…
We study the evolution of magnetic fields generated by charge segregation ahead of ionization fronts during the Epoch of Reionization, and their effects on galaxy formation. We compare this magnetic seeding process with the Biermann…