Magnetically-dominated jets inside collapsing stars as a model for gamma-ray bursts and supernova explosions
| dc.creator | Uzdensky, Dmitri A. | |
| dc.creator | MacFadyen, Andrew I. | |
| dc.date | 2007-07-04 | |
| dc.date.accessioned | 2026-07-07T10:36:15Z | |
| dc.date.available | 2026-07-07T10:36:15Z | |
| dc.description | It has been suggested that magnetic fields play a dynamically-important role in core-collapse explosions of massive stars. In particular, they may be important in the collapsar scenario for gamma-ray bursts (GRB), where the central engine is a hyper-accreting black hole or a millisecond magnetar. The present paper is focussed on the magnetar scenario, with a specific emphasis on the interaction of the magnetar magnetosphere with the infalling stellar envelope. First, the ``Pulsar-in-a-Cavity'' problem is introduced as a paradigm for a magnetar inside a collapsing star. The basic set-up of this fundamental plasma-physics problem is described, outlining its main features, and simple estimates are derived for the evolution of the magnetic field. In the context of a collapsing star, it is proposed that, at first, the ram pressure of the infalling plasma acts to confine the magnetosphere, enabling a gradual build-up of the magnetic pressure. At some point, the growing magnetic pressure overtakes the (decreasing) ram pressure of the gas, resulting in a magnetically-driven explosion. The explosion should be highly anisotropic, as the hoop-stress of the toroidal field, confined by the surrounding stellar matter, collimates the magnetically-dominated outflow into two beamed magnetic-tower jets. This creates a clean narrow channel for the escape of energy from the central engine through the star, as required for GRBs. In addition, the delayed onset of the collimated-explosion phase can explain the production of large quantities of Nickel-56, as suggested by the GRB-Supernova connection. Finally, the prospects for numerical simulations of this scenario are discussed. | |
| dc.description | Invited paper in the "Physics of Plasmas" (May 2007 special issue), based on an invited talk at the 48th Annual Meeting of the APS Division of Plasma Physics (Oct. 30 - Nov. 3, 2006, Philadelphia, PA); 24 pages, 7 figures | |
| dc.identifier | https://arxiv.org/abs/0707.0576 | |
| dc.identifier | http://arxiv.org/abs/0707.0576 | |
| dc.identifier | Phys.Plasmas14:056506,2007 | |
| dc.identifier | doi:10.1063/1.2721969 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/179991 | |
| dc.subject | Astrophysics | |
| dc.subject | Plasma Physics | |
| dc.title | Magnetically-dominated jets inside collapsing stars as a model for gamma-ray bursts and supernova explosions | |
| dc.type | text |