Influence of Alfven waves on the Thermal Instability in the Interstellar Medium

Abstract

The effect of Alfvén waves on the thermal instability of the Interstellar Medium (ISM) is investigated both analytically and numerically. A stability analysis of a finite amplitude circularly polarized Alfvén wave propagating parallel to an ambient magnetic field in a thermally unstable gas at thermal equilibrium is performed, leading to a dispersion relation which depends on 3 parameters, namely the square ratio of the sonic and Alfvén velocities ($\beta$), the wave amplitude and the ratio between the wave temporal period and the cooling time. Depending on the values of these 3 parameters, the Alfvén waves can stabilize the large-scale perturbations, destabilize those whose wavelength is a few times the Alfvén wavelength ${\lambda }_{AW}$ or leave the growth rate of the short scales unchanged. In order to investigate the non-linear regime, two different numerical experiments are performed in a slab geometry. (TBC)

accepted for publication in A&A

References in corpus (2)

• Tiny HI Clouds in the Local ISM
• Tiny HI Clouds in the Local ISM

Cited by in corpus (14)

• On the structure of the turbulent interstellar atomic hydrogen. I- Physical characteristics
• Fragmentation in Molecular Clouds and its connection to the IMF
• On the Structure of the Turbulent Interstellar Clouds
• Non-isobaric Thermal Instability
• Modelling and simulation of large-scale polarized dust emission over the southern Galactic cap using the GASS HI data
• Can WNM survive inside Molecular Clouds ?
• The Role of Ambipolar Diffusion in the Formation Process of Moderately Magnetized Diffuse Clouds
• The Interaction Between a Pulsed Astrophysical Jet and Small-Scale Heterogeneous Media
• Formation of Fluctuations in the Molecular Slab via Isobaric Thermal Instability
• Astrophysics in 2006
• The influence of magnetic field on the CNM mass fraction and its alignment with density structures
• Fragmentation of a dynamically condensing radiative layer
• An Eigenvalue Analysis of Damping in Optical Thin Plasmas
• Magnetic clumping of charged dust in the dense interstellar medium