Galaxy formation and cosmic-ray acceleration in a magnetized universe

Abstract

We study the linear magneto-hydrodynamical behaviour of a Newtonian cosmology with a viscous magnetized fluid of finite conductivity and generalise the Jeans instability criterion. The presence of the field favors the anisotropic collapse of the fluid, which in turn leads to further magnetic amplification and to an enhanced current-sheet formation in the plane normal to the ambient magnetic field. When the currents exceed a certain threshold, the resulting electrostatic turbulence can dramatically amplify the resistivity of the medium (anomalous resistivity). This could trigger strong electric fields and subsequently the acceleration of ultra-high energy cosmic rays (UHECRs) during the formation of protogalactic structures.

10 pages, ApJL in press

References in corpus (5)

• The Magnetized Universe
• Particle Acceleration in an Evolving Network of Unstable Current Sheets
• Particle Acceleration in Multiple Dissipation Regions
• Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic Ray Propagation
• Magnetic amplification in cylindrical cosmological structure

Cited by in corpus (9)

• Cosmology with inhomogeneous magnetic fields
• Amplification of Primordial Magnetic Fields by Anisotropic Gravitational Collapse
• Newtonian nonlinear hydrodynamics and magnetohydrodynamics
• Astrophysics in 2005
• Gravitational instability of the primordial plasma: anisotropic evolution of structure seeds
• Excitation of MHD waves in magnetized anisotropic cosmologies
• Magnetohydrodynamics and Plasma Cosmology
• Coexistence of Magneto-Rotational and Jeans Instabilities in an Axisymmetric Nebula
• Alfven modes driven non-linearly by metric perturbations in anisotropic magnetized cosmologies