A stability analysis of radiative shocks in the presence of a transverse magnetic field

Ramachandran, B. and Smith, M.D. (2005) A stability analysis of radiative shocks in the presence of a transverse magnetic field. Monthly Notices of the Royal Astronomical Society, 362 (4). pp. 1353-1362. ISSN 0035-8711. (doi:https://doi.org/10.1111/j.1365-2966.2005.09406.x) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1111/j.1365-2966.2005.09406.x

Abstract

Radiative shock waves may be subject to a global thermal instability in which the cooling layer and shock front undergo growing resonant oscillations. For strong hydrodynamic shocks, the presence of the overstability depends on the temperature and density indices of power-law cooling functions and the specific heat ratio (α, β and γ respectively). Here, we investigate the stabilizing influence of a transverse magnetic field by introducing the shock Alfvén number, M a, as a fourth parameter. We thus investigate the stability criteria for both molecular and atomic shocks under a wide range of conditions. In particular, we find that all molecular shocks in which the cooling increases with the temperature (α > 0) are stabilized to the first four modes if M a < 20 (β = 2). For α = -0.5, the first overtone remains stable only for M a < 8. We conclude that molecular shocks in the interstellar medium are probably stabilized by a transverse magnetic field unless exceptional circumstances arise in which the cooling strongly increases as the gas cools.

Item Type: Article
Uncontrolled keywords: Instabilities, ISM: molecules, Magnetic fields, MHD, Shock waves
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: Giles Tarver
Date Deposited: 11 Aug 2015 09:34 UTC
Last Modified: 12 Aug 2015 13:12 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/50111 (The current URI for this page, for reference purposes)
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