Related papers: Magnetic filaments: formation, stability, and feed…
Magnetic fluctuations generated by a tangling of the mean magnetic field by velocity fluctuations are studied in a developed turbulent convection with large magnetic Reynolds numbers. We show that the energy of magnetic fluctuations depends…
A fully three-dimensional computation of induction processes in a disk is performed to investigate the evolution of a large-scale magnetic field in gas-rich barred and spiral galaxies in the presence of field diffusion. As input parameters…
Primordial magnetic fields could explain the large-scale magnetic fields present in the Universe. Inflation and phase transitions in the early Universe could give rise to such fields with unique characteristics. We investigate the…
{Filaments are ubiquitous in the interstellar medium as recently emphasized by Herschel, yet their physical origin remains elusive} {It is therefore important to understand the physics of molecular clouds to investigate how filaments form…
Large scale strong magnetic fields in galaxies are generally thought to have been generated by a mean field dynamo. In order to have generated the fields observed, the dynamo would have had to have operated for a sufficiently long period of…
We perform idealised numerical simulations of magnetic buoyancy instabilities in a model of the solar tachocline. We introduce a simplified model of magnetic flux pumping in an upper layer (the convection zone), and study the effects of its…
We live near a magnetic star whose cycles of activity are driven by dynamo action beneath the surface. In the solar convection zone, rotation couples with plasma motions to build highly organized magnetic fields that erupt at the surface…
This paper examines the generation of seed magnetic fields due to the growth of cosmological perturbations. In the radiation era, different rates of scattering from photons induce local differences in the ion and electron density and…
Magnetic fields are ubiquitous in the Universe. Extragalactic disks, halos and clusters have consistently been shown, via diffuse radio-synchrotron emission and Faraday rotation measurements, to exhibit magnetic field strengths ranging from…
Filaments are an ubiquitous feature of molecular clouds, and appear to play a critical role in assembling the material to form stars. The dominant filaments are observed to have a rather narrow range of widths around $\sim 0.1$ pc, and to…
Context: Filaments are common features in molecular clouds and they play a key role in star formation (SF). Studying their life cycle is essential to fully understand the SF process. Aims: We aim to characterise the impact of magnetic field…
Recent observations have established that the magnetosphere is a system of natural complexity. The co-existence of multi-scale structures such as auroral arcs, turbulent convective flows, and scale-free distributions of energy perturbations…
Hot luminous stars show a variety of phenomena in their photospheres and winds which still lack clear physical explanation. Among these phenomena are photospheric turbulence, line profile variability (LPV), non-thermal emission, non-radial…
The question whether magnetic fields play an important role in the processes of molecular cloud and star formation has been debated for decades. Recent observations have revealed a simple picture that may help illuminate these questions:…
Stars form in highly-magnetised, supersonic turbulent molecular clouds. Many of the tools and models that we use to carry out star formation studies rely upon the assumption of cloud isotropy. However, structures like high-density filaments…
Large masses of absorbing material are inferred to exist in cooling flows in clusters of galaxies from the excess X-ray absorption in the spectra of some X-ray clusters. The absorbing material is probably in the form of cold clouds…
We present observational evidence for oscillations of magnetic flux density in the quiet areas of the Sun. The majority of magnetic fields on the solar surface have strengths of the order of or lower than the equipartition field (300-500…
Context: Observations indicate that the `quiet' solar photosphere outside active regions contains considerable amounts of magnetic energy and magnetic flux, with mixed polarity on small scales. The origin of this flux is unclear. Aims: We…
Observations with the 1-m Swedish Solar Telescope of the flows seen in penumbral filaments are presented. Time sequences of bright filaments show overturning motions strikingly similar to those seen along the walls of small isolated…
One of the key questions in solar physics that remains to be answered concerns the strength and the distribution of the magnetic fields at the base of the convection zone. The flux tube dynamics requires that toroidal fields of strength as…