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The linear stability of chains of magnetic vortices in a plasma isinvestigated analytically in two dimensions by means of a reduced fluid modelassuming a strong guide field and accounting for equilibrium electrontemperature anisotropy. The chain of magnetic vortices is modelled by means ofthe classical "cat's eyes" solutions and the linear stability is studied byanalysing the second variation of a conserved functional, according to theEnergy-Casimir method. The stability analysis is carried out on the domainbounded by the separatrices of the vortices. Two cases are considered,corresponding to a ratio between perpendicular equilibrium ion and electrontemperature much greater or much less than unity, respectively. In the formercase, equilibrium flows depend on an arbitrary function. Stability is attainedif the equilibrium electron temperature anisotropy is bounded from above andfrom below, with the lower bound corresponding to the condition preventing thefirehose instability. A further condition sets an upper limit to the amplitudeof the vortices, for a given choice of the equilibrium flow. For cold ions, twosub-cases have to be considered. In the first one, equilibria correspond tothose for which the velocity field is proportional to the local Alfv\'envelocity. Stability conditions imply: an upper limit on the amplitude of theflow, which automatically implies firehose stability, an upper bound on theelectron temperature anisotropy and again an upper bound on the size of thevortices. The second sub-case refers to equilibrium electrostatic potentialswhich are not constant on magnetic flux surfaces and the resulting stabilityconditions correspond to those of the first sub-case in the absence of flow.

Linear stability of magnetic vortex chains in a plasma in the presence of equilibrium electron temperature anisotropy