Jena 2013 – scientific programme

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GR: Fachverband Gravitation und Relativitätstheorie

GR 10: Numerische Relativitätstheorie II

GR 10.3: Talk

Wednesday, February 27, 2013, 17:00–17:15, HS 6

Evolution of magnetized hypermassive neutron stars — •Daniel Siegel, Riccardo Ciolfi, and Luciano Rezzolla — Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Potsdam-Golm, Germany

Differentially rotating hypermassive neutron stars (HMNSs) are metastable configurations which can be formed in the latest stage of binary neutron star mergers. Their eventual collapse produces a spinning black hole surrounded by a hot and thick accretion disk. The dynamics of such a system is of crucial importance, since it could generate the relativistic jets observed in short gamma-ray bursts. By performing simulations of very high resolution, we discuss the influence of magnetic fields on the evolution of HMNSs. In particular, we provide convincing evidence for the occurrence of the magneto-rotational instability (MRI), which is responsible for strong magnetic field amplification. Characteristic features of the MRI are discussed and quantities such as the characteristic growth rate and the wavelength of the fastest growing mode are extracted and compared with analytical predictions. We also show the emergence of coherent channel flows and their eventual rearrangement through reconnection.