
1 Introduction


2 Linearized equations of the shocked Bondi flow


3 Spectrum of eigenfrequencies


4 The sound of vorticity


5 Vorticalacoustic instability at high frequency


6 Vorticalacoustic instability at low frequency


7 Effects of postshock acceleration: A global instability
with a local criterion


8 Discussion


9 Conclusions


Appendix A: Vorticity perturbations produced by the perturbed shock


Appendix B: Approximations of the acoustic perturbation


Appendix C: Formulation of the boundary value problem


Appendix D: Calculation of


Appendix E: Decomposition of the perturbation onto vorticity waves and
acoustic waves in the WKB approximation


Appendix F: WKB approximation of the dispersion relation


Appendix G: Analysis of the phase relation of the two cycles


Appendix H: Pseudosound approximation of the dispersion relation


References
