Research Note

Wave instabilities in an anisotropic magnetized space plasma

¹ Astrophysikalisches Institut Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany e-mail: JStaude@aip.de
² Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences (IZMIRAN), Troitsk City, Moscow Region 142190, Russia e-mail: [Namig;KVD]@izmiran.ru
³ Shamakhy Astrophysical Observatory of the Azerbaijan Academy of Sciences (ShAO), Baku 1000, Azerbaijan

Received: 1 April 2008
Accepted: 1 July 2008

Abstract

Aims. We study wave instability in an collisionless, rarefied hot plasma (e.g. solar wind or corona). We consider the anisotropy produced by the magnetic field, when the thermal gas pressures across and along the field become unequal.

Methods. We apply the 16-moment transport equations (obtained from the Boltzmann-Vlasov kinetic equation) including the anisotropic thermal fluxes. The general dispersion relation for the incompressible wave modes is derived.

Results. It is shown that a new, more complex wave spectrum with stable and unstable behavior is possible, in contrast to the classic fire-hose modes obtained in terms of the 13-moment integrated equations.