English
Related papers

Related papers: Numerical simulations of coronal magnetic field lo…

200 papers

We investigate the formation of circumstellar disks and outflows subsequent to the collapse of molecular cloud cores with the magnetic field and turbulence. Numerical simulations are performed by using an adaptive mesh refinement to follow…

Solar and Stellar Astrophysics · Physics 2017-04-26 Tomoaki Matsumoto , Masahiro N. Machida , Shu-ichiro Inutsuka

While magnetic fields have long been considered to be important for the evolution of magnetic non-degenerate stars and compact stars, it has become clear in recent years that actually all of the stars are deeply affected. This is…

Solar and Stellar Astrophysics · Physics 2021-02-03 Koh Takahashi , Norbert Langer

We study the effects of magnetic fields on the evolution of differentially rotating neutron stars, which can form in stellar core collapse or binary neutron star coalescence. Magnetic braking and the magnetorotational instability (MRI) both…

We investigate the rotational dynamics of disk accretion around a strongly magnetized neutron star with an aligned dipole field. The magnetospheric field is assumed to thread the disk plasma both inside and outside the corotation radius. As…

Astrophysics · Physics 2009-11-10 M. Hakan Erkut , M. Ali Alpar

Some contracting or expanding stars are thought to host a large-scale magnetic field in their radiative interior. By interacting with the contraction-induced flows, such fields may significantly alter the rotational history of the star.…

Solar and Stellar Astrophysics · Physics 2022-05-18 B. Gouhier , L. Jouve , F. Lignières

Numerical simulations of planet-disk interactions are usually performed with hydro-codes that -- because they consider only an annulus of the disk, over a 2D grid -- can not take into account the global evolution of the disk. However, the…

Astrophysics · Physics 2008-11-26 A. Crida , A. Morbidelli , F. Masset

We present results of global 3D MHD simulations of disk accretion to a rotating star with dipole and more complex magnetic fields using a Godunov-type code based on the "cubed sphere" grid developed earlier in our group. We describe the…

Solar and Stellar Astrophysics · Physics 2009-01-28 Marina M. Romanova , Alexander V. Koldoba , Galina V. Ustyugova , Akshay K. Kulkarni , Min Long , Richard V. E. Lovelace

Evidence of magnetic interaction between late-type stars and close-in giant planets is provided by the observations of stellar hot spots rotating synchronously with the planets and showing an enhancement of chromospheric and X-ray fluxes.…

Solar and Stellar Astrophysics · Physics 2015-05-13 A. F. Lanza

Magnetic fields are known to be dynamically important in the interstellar medium of our own Galaxy, and they are ubiquitously observed in diffuse gas in the halos of galaxies and galaxy clusters. Yet, magnetic fields have typically been…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 R. Pakmor , V. Springel

We carried out two dimensional high-resolution magnetohydrodynamic (MHD) simulations of an accretion disk around a weakly magnetized neutron star. General relativistic effects are taken into account by using pseudo-Newtonian potential of…

Astrophysics · Physics 2009-11-06 Y. Kato , H. R. Hayashi , S. Miyaji , R. Matsumoto

I show in this paper that two types of magnetic torques can appear in the interaction between an accretion disc and a magnetic accretor. There is the well-known torque resulting from the difference in angular velocity between the accretion…

Astrophysics · Physics 2009-10-30 Ulf Torkelsson

This Letter investigates the origin of the asymmetric magnetic field line geometry in the ergospheric disk (and the corresponding asymmetric powerful jet) in 3-D perfect magnetohydrodynamic (MHD) numerical simulations of a rapidly rotating…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Brian Punsly

We examine, parametrically, the interaction between the magnetosphere of a rotating, young stellar object (YSO) and a circumstellar accretion disk using 2.5-D (cylindrically symmetric) numerical magnetoydrodynamic simulations. The…

Astrophysics · Physics 2009-11-07 Sean Matt , Anthony Goodson , Robert Winglee , Karl-Heinz Bohm

A new type of wind - a conical wind - has been discovered in axisymmetric magnetohydrodynamic simulations of the disk-magnetosphere interaction in cases where the magnetic field of the star is bunched into an X-type configuration. Such a…

Solar and Stellar Astrophysics · Physics 2009-01-28 M. M. Romanova , G. V. Ustyugova , A. V. Koldoba , R. V. E. Lovelace

We have carried out and analyzed a set of axisymmetric MHD simulations of the evolution of a turbulent/diffusive accretion disc around an initially unmagnetized star. The disc is initially threaded by a weak magnetic field where the…

High Energy Astrophysical Phenomena · Physics 2015-06-12 S. Dyda , R. V. E. Lovelace , G. V. Ustyugova , P. S. Lii , M. M. Romanova , A. V. Koldoba

We investigate the evolution of a thin viscous disc surrounding magnetic star, including the spindown of the star by the magnetic torques it exerts on the disc. The transition from an accreting to a non-accreting state, and the change of…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Caroline D'Angelo , Henk Spruit

Long-term evolution of a stellar orbit captured by a massive galactic center via successive interactions with an accretion disc has been examined. An analytical solution describing evolution of the stellar orbital parameters during the…

Astrophysics · Physics 2009-10-30 D. Vokrouhlicky , V. Karas

In star forming disk galaxies, matter circulation between stars and the interstellar gas, and, in particular the energy input by random and clustered supernova explosions, determine the dynamical and chemical evolution of the ISM, and hence…

Astrophysics · Physics 2009-11-10 Miguel A. de Avillez , Dieter Breitschwerdt

We investigate outflows from the disk-magnetosphere boundary of rotating magnetized stars in cases where the magnetic field of a star is bunched into an X-type configuration using axisymmetric and full 3D MHD simulations. Such configuration…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. M. Romanova , G. V. Ustyugova , A. V. Koldoba , R. V. E. Lovelace

Aims: We determine the steady-state of an axisymmetric thin accretion disc with an internal dynamo around a magnetised star. Methods: Starting from the vertically integrated equations of magnetohydrodynamics we derive a single ordinary…

High Energy Astrophysical Phenomena · Physics 2010-01-26 Solomon Belay Tessema , Ulf Torkelsson