Templates of binary-induced spiral-shell patterns around mass-losing
  post-main sequence stars
  The morphological properties of the outflowing circumstellar envelopes
surrounding mass-losing stars in eccentric binary systems are presented from a
set of three-dimensional hydrodynamical model simulations. Based on four
template models of the envelope viewed for a range of inclination angles of the
systems, we implement interpretative tools for observations at high
spectral/angular resolutions (as illustrated via velocity channel maps as well
as position-velocity, radius-velocity, and angle-radius diagrams). Within this
framework, the image and kinematical structures can be used to place
constraints on the orbital parameters of the system. Specifically, three unique
characteristic patterns in the envelopes are found that distinguish these
systems from those in binary systems in circular orbits. Bifurcation of the
spiral pattern, asymmetry in the interarm density depression, and a concurrent
spiral/ring appearance all point to a binary system with an eccentric orbit.
The methodology presented in this paper is illustrated in an analysis of recent
radio observations of several asymptotic giant branch stars.
