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Session 7 - Planetary & Other Nebulae.
Display session, Monday, June 09
South Main Hall,

[7.08] Instability of Isothermal Stellar Wind Bowshocks

J. Koerwer (Enloe High School), J. M. Blondin (NCSU)

We use numerical hydrodynamic simulations to investigate the stability of Stellar Wind Bowshocks in the limit of strong radiative cooling behind both the bowshock and the wind termination shock. The nonlinear thin shell instability (NTSI) and the transverse acceleration instability (TAI) are hypothesized to be the cause of the instability. The situation is modeled as the interaction of a spherically diverging wind and an oncoming planar wind. The effect of various wind velocities on the instability is studied. With high Mach number winds, the instability consistently disrupts the bowshock so as to make it grow beyond twice the standoff radius, as determined by the densities of the stellar wind and the Interstellar Medium. The internal dynamics of the bowshock and the nature of the bowshock deformation suggest that the dominant cause of the instability is the NTSI.

Program listing for Monday