English
Related papers

Related papers: Unipolar Induction Star-Disk Interaction

200 papers

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

Accreting pulsars power relativistic jets, and display a complex spin phenomenology. These behaviours may be closely related to the large-scale configuration of the star's magnetic field, shaped by its interaction with the surrounding…

High Energy Astrophysical Phenomena · Physics 2017-06-21 Kyle Parfrey , Anatoly Spitkovsky , Andrei M. Beloborodov

We examine various ways in which disk accretion can heat an accreting star. These include 1) radiation emitted from the disk surface which is intercepted by the stellar surface, 2) radiative flux directly across the disk-star interface, and…

Astrophysics · Physics 2009-10-28 Robert Popham

We critically examine the theory of disk locking, which assumes that the angular momentum deposited on an accreting protostar is exactly removed by torques carried along magnetic field lines connecting the star to the disk. In this letter,…

Astrophysics · Physics 2009-11-10 Sean Matt , Ralph E. Pudritz

An analytical model is developed for the screening of the external magnetic field of a rotating, axisymmetric neutron star due to the accretion of plasma from a disk. The decrease of the field occurs due to the electric current in the…

Astrophysics · Physics 2007-05-23 R. V. E. Lovelace , M. M. Romanova , G. S. Bisnovatyi-Kogan

We investigate the dynamical interaction of a central star cluster surrounding a super-massive black hole and a central accretion disk. The dissipative force acting on stars in the disk leads to an enhanced mass flow towards the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Andreas Just , Denis Yurin , Maxim Makukov , Peter Berczik , Chingis Omarov , Rainer Spurzem , Emanuel Y. Vilkoviskij

The powerful narrow jets observed to emanate from many compact accreting objects may arise from the twisting of a magnetic field threading a differentially rotating accretion disk which acts to magnetically extract angular momentum and…

Astrophysics · Physics 2009-11-06 R. V. E. Lovelace , H. Li , G. V. Ustyugova , M. M. Romanova , S. A. Colgate

Stars interact with their close-in planets through radiation, gravitation, and magnetic fields. We investigate the energy input to a planetary atmosphere by reconnection between stellar and planetary magnetic fields and compare it to the…

Earth and Planetary Astrophysics · Physics 2013-07-10 A. F. Lanza

A magnetic field connecting a Kerr black hole to a disk rotating around it can extract energy and angular momentum from the black hole and transfer them to the disk if the black hole rotates faster than the disk. The energy can be…

Astrophysics · Physics 2009-11-07 Li-Xin Li

We report results from calculations investigating stationary magnetic field configurations in accretion discs around magnetised neutron stars. Our strategy is to start with a very simple model and then progressively improve it providing…

Solar and Stellar Astrophysics · Physics 2014-11-20 L. Naso , J. C. Miller

The inner region of the accretion disk around a magnetized star is subjected to magnetic torques that induce warping and precession of the disk. These torques arise from interactions between the stellar field and the induced electric…

Astrophysics · Physics 2007-05-23 Dong Lai

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

With the neutron star rotating under a stationary magnetic field generating unipolar induction, charges are driven to the pulsar surface according to their signs, and are uploaded to the magnetosphere along the magnetic field lines. In the…

High Energy Astrophysical Phenomena · Physics 2021-12-20 K. H. Tsui

We present a 3-D ideal MHD simulation of magnetospheric accretion onto a non-rotating star. The accretion process unfolds with intricate 3-D structures driven by various mechanisms. First, the disc develops filaments at the magnetospheric…

Solar and Stellar Astrophysics · Physics 2023-12-18 Zhaohuan Zhu , James M. Stone , Nuria Calvet

We propose that the accretion disks fueling active galactic nuclei are supported vertically against gravity by a strong toroidal ($\phi-$direction) magnetic field that develops naturally as the result of an accretion disk dynamo. The…

High Energy Astrophysical Phenomena · Physics 2016-10-12 Mitchell C. Begelman , Joseph Silk

Models of planet-disk interaction are mainly based on 2D and 3D viscous hydrodynamical simulations. Accretion is classically prescribed by an alpha parameter which characterizes the turbulent radial transport of angular momentum (AM) in the…

Solar and Stellar Astrophysics · Physics 2023-05-22 Gaylor Wafflard-Fernandez , Geoffroy Lesur

The presence of giant gaseous planets that reside in close proximity to their host stars may be a consequence of large-scale radial migration through the proto-planetary nebulae. Within the context of this picture, significant orbital…

Earth and Planetary Astrophysics · Physics 2015-06-17 Konstantin Batygin , Fred C. Adams

We formulate a general, steady-state model for the torque on a magnetized star from a surrounding accretion disc. For the first time, we include the opening of dipolar magnetic field lines due to the differential rotation between the star…

Astrophysics · Physics 2009-11-10 Sean Matt , Ralph E. Pudritz

Large scale magnetic field threading an accretion disk is a key ingredient in the jet formation model. The most attractive scenario for the origin of such a large scale field is the advection of the field by the gas in the accretion disk…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Xinwu Cao , H. C. Spruit

We investigate the properties of a hot accretion flow bathed in a poloidal magnetic field. We consider an axisymmetric viscous resistive flow in the steady state configuration. We assume the dominant mechanism of energy dissipation is due…

High Energy Astrophysical Phenomena · Physics 2017-08-30 Maryam Samadi , Shahram Abbassi