skip to main content

SciTech ConnectSciTech Connect

Title: The evolution of high-temperature plasma in magnetar magnetospheres and its implications for giant flares

In this paper we propose a new mechanism describing the initial spike of giant flares in the framework of the starquake model. We investigate the evolution of a plasma on a closed magnetic flux tube in the magnetosphere of a magnetar in the case of a sudden energy release, and discuss the relationship with observations of giant flares. We perform one-dimensional, numerical simulations of the relativistic magnetohydrodynamics in Schwarzschild geometry. We assume energy is injected at the footpoints of the loop by a hot star surface containing random perturbations of the transverse velocity. Alfvén waves are generated and propagate upward, accompanying very hot plasma which is also continuously heated by nonlinearly generated compressive waves. We find that the front edges of the fireball regions collide at the top of the tube with their symmetrically launched counterparts. This collision results in an energy release that can describe the light curve of the initial spikes of giant flares.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, Heidelberg D69117 (Germany)
  2. Institute of Particle and Nuclear Studies, KEK, 1-1, Oho, Tsukuba 305-0801 (Japan)
  3. Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
  4. Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa city, Chiba 277-8582 (Japan)
Publication Date:
OSTI Identifier:
22356815
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 787; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALFVEN WAVES; COLLISIONS; COMPUTERIZED SIMULATION; DISTURBANCES; EVOLUTION; HOT PLASMA; MAGNETIC FIELDS; MAGNETIC FLUX; MAGNETOHYDRODYNAMICS; NEUTRON STARS; NUCLEAR FIREBALLS; ONE-DIMENSIONAL CALCULATIONS; PERTURBATION THEORY; RANDOMNESS; RELATIVISTIC RANGE; SHOCK WAVES; STARS; STELLAR FLARES; SURFACES; VISIBLE RADIATION