Related papers: Evolution of a magnetic field in a differentially …
The origin and evolution of cosmic magnetic fields as well as the influence of the magnetic fields on the evolution of galaxies are unknown. Though not without challenges, the dynamo theory can explain the large-scale coherent magnetic…
The solar tachocline is shown as hydrodynamically stable against nonaxisymmetric disturbances if it is true that no cos^{4}\theta term exists in its rotation law. We also show that the toroidal field of 200 Gauss amplitude which produces…
We investigate the change in stellar magnetic topology across the fully-convective boundary and its effects on coronal properties. We consider both the magnitude of the open flux that influences angular momentum loss in the stellar wind and…
Tayler instability of toroidal magnetic fields $B_\phi$ is broadly invoked as a trigger for turbulence and angular momentum transport in stars. This paper presents a systematic revision of the linear stability analysis for a rotating,…
Stars are, generically, rotating and magnetised objects with a misalignment between their magnetic and rotation axes. Since a magnetic field induces a permanent distortion to its host, it provides effective rigidity even to a fluid star,…
Instabilities in magnetic fields wound up by differential rotation as reviewed in Spruit (1999) are discussed with some detail and new developments added. In stellar models which include magnetic torques, the differential rotation tends to…
We present analytical and numerical studies of magnetorotational instabilities occuring in magnetized accretion disks. In these studies we make use of the linearised compressible MHD equations. These calculations are performed for general…
Neutron stars are the most compact horizonless objects in the Universe, exhibiting the strongest known magnetic fields. They are potential sources of coincident gravitational waves and electromagnetic radiation across the entire spectrum.…
Context: Observations suggest that magnetic fields of disk-bearing stars may have non-dipolar configurations. However, the influence of these configurations on magnetospheric accretion remains poorly understood. Aims: We aim to simulate…
Using an axisymmetric numerical code, we perform an extensive study of the magnetic field configurations in non-rotating neutron stars, varying the mass, magnetic field strength and the equation of state. We find that the monopolar…
Large-scale magnetic fields are key ingredients of magnetically driven disk accretion. We study how large-scale poloidal fields evolve in accretion disks, with the primary aim of quantifying the viability of magnetic accretion mechanisms in…
Neutron stars contain persistent, ordered magnetic fields that are the strongest known in the Universe. However, their magnetic fluxes are similar to those in magnetic A and B stars and white dwarfs, suggesting that flux conservation during…
Several observations of astrophysical jets show evidence of a structure in the direction perpendicular to the jet axis, leading to the development of "spine & sheath" models of jets. Most studies focus on a two-component jet consisting of a…
Buoyancy of the fossil magnetic field in the accretion disks of young stars is investigated. It is assumed that the Parker instability leads to the formation of slender flux tubes of toroidal magnetic field in the regions of effective…
Surface magnetic fields have a strong impact on stellar mass loss and rotation and, as a consequence, on the evolution of massive stars. In this work we study the influence of an evolving dipolar surface fossil magnetic field with an…
There is a large change in surface rotation rates of sun-like stars on the pre-main sequence and early main sequence. Since these stars have dynamo driven magnetic fields, this implies a strong evolution of their magnetic properties over…
We reconstruct the 3D structure of magnetic fields, which were seeded by density perturbations during the radiation dominated epoch of the Universe and later on were evolved by structure formation. To achieve this goal, we rely on three…
While the presence of magnetic fields on low-mass stars is attributed to a dynamo process essentially driven by convective motions, the existence of magnetic fields on intermediate-mass stars has very likely other reasons. Presuming that…
We study global non-axisymmetric stationary perturbations of aligned and unaligned logarithmic spiral configurations in an axisymmetric composite differentially rotating disc system of scale-free stellar and isopedically magnetized gas…
Recent numerical magnetohydrodynamic calculations by Braithwaite and collaborators support the `fossil field' hypothesis regarding the origin of magnetic fields in compact stars and suggest that the resistive evolution of the fossil field…