The cometary cavity created by an aligned streaming   environment/collimated outflow interaction
  We present a "thin shell" model of the interaction of a biconical outflow and a streaming environment (aligned with the direction of the flow), as well as numerical (axisymmetric) simulations of such an interaction. A similar situation, although in a more complex setup, takes place at the head of the cometary structure of Mira. Thus, for most of the numerical simulations we explore parameters consistent with the observed bipolar outflow from Mira B. For these parameters, the interaction is non-radiative, so that a rather broad jet/streaming environment interaction region is formed. In spite of this, a reasonable agreement between the thin-shell analytic model and the numerical simulations is obtained. 
D. L\'opez-C\'amara, A. Esquivel, J. Cant\'o, A. C. Raga, P. F   Vel\'azquez, and A. Rodr\'iguez-Gonz\'alez
astro-ph.HE astro-ph.SR