Gravitational and magnetosonic waves in gamma-ray bursts

Abstract

Abstract.One of the possible sources of gamma-ray bursts (s) are merging, compact neutronstar binaries. More than 90% of the binding energy of such a binary is released in the form of gravitational waves (s) in the last few seconds of the spiral-in phase before the formation of a black hole. In this article we investigate whether a fraction of this  energy is transferred to magnetohydrodynamic waves in the magnetized plasma wind around the binary. Using the 3 + 1 orthonormal tedrad formalism, we study the propagation of a monochromatic, plane fronted, linearly polarized  perpendicular to the ambient magnetic field in an ultra-relativistic wind, first in the comoving and then in the observer frame. A closed set of general relativistic magnetohydrodynamic () equations is derived in the form of conservation laws for electric charge, matter energy, momentum and magnetic energy densities. We linearize the  equations under the action of a monochromatic , which acts as a driver and find that fast magneto-acoustic waves grow, with amplitudes proportional to the  amplitude and frequency and the strength of the background magnetic field.

The general relativistic magnetohydrodynamic dynamo equation

“…These assumptions will make it possible to describe a two‐component plasma in terms of a one‐fluid description, as the electrons can be considered inertialess (see also e.g. Papadopoulos et al 2001; Papadopoulos, Vlahos & Esposito 2002; Servin & Brodin 2003; Moortgat & Kuijpers 2003, 2004). The one‐fluid description means a tremendous computational simplification, especially for complicated geometries.…”

Hunting Gravitational Waves with Multi-Messenger Counterparts: Australia’s Role

“…Such mechanisms include excitation of the plasma surrounding a compact binary merger by GWs (Moortgat & Kuijpers, 2005), from a dynamically-generated magnetic field after the merger (Pshirkov & Postnov, 2010), or from the onset of the collision of the forward shock with the surrounding medium (Usov & Katz, 2000;Sagiv & Waxman, 2002). However, the detectability of emission from these processes will be dependent upon the scattering by the surrounding environment (Macquart, 2007).…”

Harmonic generation of gravitational wave induced Alfvén waves

“…The application of gravitational wave processes to astrophysics has been discussed by for example Refs. [11,12,13,14,15], and to cosmology by Refs. [16,17,18,19].…”