  An analytic model of the heliosheath (HS) between the termination shock (TS)
and the heliopause (HP) is developed in the limit in which the interstellar
flow and magnetic field are neglected. The heliosphere in this limit is
axisymmetric and the overall structure of the HS and HP are controlled by the
solar magnetic field even in the limit in which the ratio of the plasma to
magnetic field pressure, $\beta=8\pi P/B^2$, in the HS is large. The tension of
the solar magnetic field produces a drop in the total pressure between the TS
and the HP. This same pressure drop accelerates the plasma flow downstream of
the TS into the North and South directions to form two collimated jets. The
radii of these jets are controlled by the flow through the TS and the
acceleration of this flow by the magnetic field -- a stronger solar magnetic
field boosts the velocity of the jets and reduces the radii of the jets and the
HP. Magnetohydrodynamic (MHD) simulations of the global helioshere embedded in
a stationary interstellar medium match well with the analytic model. The
results suggest that mechanisms that reduce the HS plasma pressure downstream
of the TS can enhance the jet outflow velocity and reduce the HP radius to
values more consistent with the Voyager 1 observations than in current global
models.
