that one expects

$$Q^{2} \sim \frac{\dot{M}_{j}}{\dot{M}_{a}}.$$

It is reassuring that for the jets associated with T Tauri stars for example, values of $\dot{M}_{j} / \dot{M}_{a}$ of between 0.1 and 0.01 on average are observationally inferred and therefore of order $0.3<Q<0.1$ (e.g Hartigan et al. 1996, Gullbring et al. 1998, Hartigan et al. 2004, Ferreira et al. 2006). These are compatible with the value of $Q=5 \times 10^{-2}$ used to plot fig. (1), and hence ones which will readily yield jet solutions. Given the substantial spread in the inferred values quoted above, we see that vales of $10^{-3}$ or even $10^{-4}$ occur. We note that for smaller values of $Q$ the jet becomes more centrally localised, making the numerical problem of integrating trajectories challenging. In general, thin disk jet solutions will appear for lower values of $Q$, or conversely, jet solutions for low values of $Q$ require thinner disks, small values of $\theta_{0}$, for the function $g_{\theta}$ used in the example.

![The figure gives trajectories for the complete solution, for a range of initial vertical height positions at $R=3.0$. The dimensionless parameter of the problem was chosen as $Q=10^{-4}$. We see a very thin disk developing a central bulge inwards of 