相关论文: Instability-driven interfacial dynamo in protoneut…
We provide a consistent theory of the tachocline confinement (or anisotropic momentum transport) within an hydrodynamical turbulence model. The goal is to explain helioseismological data, which show that the solar tachocline thickness is at…
The Sun and other cool stars harbouring outer convection zones manifest magnetic activity in their atmospheres. The connection between this activity and the properties of a deep-seated dynamo generating the magnetic flux is not well…
In the solar corona, several mechanisms of the drift wave instability can make the mode growing up to amplitudes at which particle acceleration and stochastic heating by the drift wave take place. The stochastic heating, well known from…
We demonstrate that for weak flares the dependence on spottedness can be rather weak. The fact is that such flares can occur both in small and large active regions. At the same time, powerful large flares of classes M and X occur much more…
Generation and diffusion of the magnetic field on the Sun is a key mechanism responsible for solar activity on all spatial and temporal scales - from the solar cycle down to the evolution of small-scale magnetic elements in the quiet Sun.…
The importance of the existence of a radiative core in generating a solar-like magnetic dynamo is still unclear. Analytic models and magnetohydrodynamic simulations of stars suggest the thin layer between a star's radiative core and its…
We investigate the chiral magnetic instability in the crust of a neutron star as a potential mechanism for amplifying magnetic fields. This instability may become active when small deviations from chemical equilibrium are sustained over…
Stars are changing entities in a constant evolution during their lives. At non-secular time scales (from seconds to years) the effect of dynamical processes such as convection, rotation, and magnetic fields can modify the stellar…
For cylindrical differentially rotating plasmas, we study large-scale magnetic field generation from finite amplitude non-axisymmetric perturbations by comparing numerical simulations with quasi-linear analytic theory. When initiated with a…
The solar tachocline is a shear layer located at the base of the solar convection zone. The horizontal shear in the tachocline is likely turbulent, and it is often assumed that this turbulence would be strongly anisotropic as a result of…
We study mean field dynamo action in renovating flows with finite and non zero correlation time ($\tau$) in the presence of shear. Previous results obtained when shear was absent are generalized to the case with shear. The question of…
Barotropic rotation and radiative equilibrium are mutually incompatible in stars. The issue is often addressed by allowing for a meridional circulation, but this is not devoid of theoretical complications. Models of rotation in the Sun…
The possibility of explaining shear flow dynamos by a magnetic shear-current (MSC) effect is examined via numerical simulations. Our primary diagnostics is the determination of the turbulent magnetic diffusivity tensor $\boldsymbol{\eta}$.…
The release of spin-down energy by a magnetar is a promising scenario to power several classes of extreme explosive transients. However, it lacks a firm basis because magnetar formation still represents a theoretical challenge. Using the…
Meteoritic studies of solar system objects show evidence of nucleosynthetic heterogeneities that are inherited from small presolar grains (< 10 $\mu$m) formed in stellar environments external to our own. The initial distribution and…
Tearing instability, also known as plasmoid instability, is an effective mechanism to speed up magnetic reconnection process, working in a wide range of magnetized plasma systems with different spatial scales, ionization degrees, and…
The Sun is a magnetic star, and the only spatio-temporally resolved astrophysical system displaying turbulent MHD thermal convection. This makes it a privileged object of study to understand fluid turbulence in extreme regimes and its…
In the solar convection zone, rotation couples with intensely turbulent convection to drive a strong differential rotation and achieve complex magnetic dynamo action. Our sun must have rotated more rapidly in its past, as is suggested by…
Recently, Silvers, Vasil, Brummell, & Proctor (2009), using numerical simulations, confirmed the existence of a double diffusive magnetic buoyancy instability of a layer of horizontal magnetic field produced by the interaction of a shear…
Star formation in our Galaxy occurs in molecular clouds that are self-gravitating, highly turbulent, and magnetized. We study the conditions under which cloud cores inherit large-scale magnetic field morphologies and how the field is…