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On the linear analysis of unstable radiative shocks

Ramachandran, B., Smith, M.D. (2005) On the linear analysis of unstable radiative shocks. Monthly Notices of the Royal Astronomical Society, 357 (2). pp. 707-721. ISSN 0035-8711. (doi:10.1111/j.1365-2966.2005.08691.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)

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. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1111/j.1365-2966.2005.08691.x

Abstract

We study the stability properties of strong hydrodynamic shocks and their associated radiative cooling layers. We explore a range of conditions which covers both molecular and atomic gas impacting against a rigid wall. Through a linear analysis employing a cooling function of the form ? ? ? ?T ? and a specific heat ratio of ?, we determine the overstability regime in the parameter space consisting of ?, ? and ?. In general, if ? is sufficiently low, the fundamental mode leads to long-wavelength growing oscillations. For the fundamental mode, we find that values of ? corresponding to molecular hydrodynamics lead to a significantly restricted instability range for ? in comparison with the shocks in a monatomic medium. The conditions for the growth of higher-order modes, however, are relatively unchanged. This predicts that certain molecular shocks are prone to displaying signatures of small-scale rapid variability. Dissociative shocks, however, can be subject to a large-scale overstability if subsequent molecule formation in the cooling layer abruptly increases the cooling rate. In contrast to the dynamical rippling overstability, the cooling overstability is suppressed for a sufficiently low specific heat ratio.

Item Type: Article
DOI/Identification number: 10.1111/j.1365-2966.2005.08691.x
Uncontrolled keywords: Hydrodynamics, Instabilities, ISM: kinematics and dynamics, ISM: molecules, 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 09:38 UTC
Last Modified: 29 May 2019 15:54 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/50116 (The current URI for this page, for reference purposes)
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