Table 7: Approximate properties of SNR blast waves at the transition into the pressure-driven snowplough stage for different values of $T_{\rm ISM}$and n0, chosen to demonstrate the conditions under which SNRs in the pressure-driven snowplough stage have low Mach number forward shocks which are susceptible to the radiative overstability. The age of the SNR at the onset of shell formation, $t_{\rm tr}$, the shock velocity, $v_{\rm s}$, and the Mach number, M, at this time, are given. The values illustrate that overstable low Mach number radiative shocks in SNRs will exist. For $T_{\rm ISM} = 10^{6}\;$K and $n_{0} = 3.5 \times 10^{-3}\;\hbox{${\rm{\rm\thinspace cm}^{-3}~}$ }$ the blast wave becomes subsonic before transition to the pressure-driven snowplough stage.
$T_{\rm ISM}$ n0 $t_{\rm tr}$ $v_{\rm s}$ $T_{\rm s}/T_{\rm ISM}$ M
(K) ( ${\rm {\rm\thinspace cm}^{-3}}$) (105 yr) $(\hbox{${\rm {\rm\thinspace km}{\rm\thinspace s}^{-1}~}$ })$    
$2 \times 10^{5}$ 10-3 11.2 115 1.7 1.7
  10-2 3.3 151 2.4 2.3
  10-1 1.0 198 3.6 3.0
  1 0.3 260 5.6 3.9
106 10-3 11.2 115 - 0.8
  10-2 3.3 151 1.0 1.0
  10-1 1.0 198 1.5 1.5
  1 0.3 260 1.7 1.7


Source LaTeX | All tables | In the text

Article Contents
1 Introduction
2 Properties of low Mach number shocks
3 Hydrodynamical simulations
4 Discussion
5 Summary
References
List of tables
List of figures