7.2.1 The inner region (0 to 1.1kpc)

Our conclusions for this region are tentative because of the limited transverse resolution of the data. The region is characterized by:

1. low intrinsic emissivity;
2. slow lateral expansion (a cone of intrinsic half-angle 6.7$^\circ$) and
3. a significant component of emission arising in slow-moving material.

The fitted central velocity is 0.8 - 0.9$c$. We have no evidence for deceleration in this region, but we cannot exclude the presence of higher-velocity (Doppler-hidden) flow components. Simple adiabatic models are grossly inconsistent with the emissivity profile.