Hans Moritz Günther edited introduction.tex  about 10 years ago

Commit id: 4f97b61851b10a03e328d7f4f0acf029aba89db5

deletions | additions      

       

In \citet{2009A&A...493..579G} (from now on ``paper I'') we showed that this inner X-ray emission can be explained by shock heating of a jet component moving with 400-500~km~s$^{-1}$. For the case of DG~Tau the mass flux in this component is less than $10^{-3}$ of the total mass flux in the jet or even lower if the same material is reheated in several consecutive shocks. If the density in the fast outflow is $>10^5$~cm$^{-3}$ then the cooling length of this shock is only a few AU and in the optical it would be unresolved and outshined by the more luminous emission from the more massive, but slower jet component. However, the stationary nature of the X-ray emission remained unexplained in this scenario.  In this article we explain how such a shock can be caused by the recollimation of the inner jet due to the shape of the boundary between stellar winds and disk winds similar to the work of \citet{2012MNRAS.422.2282K} for relativistic jets. This scenario naturally explains the stationary appearence and its location within the jet collimation region. In section~\ref{sect:model} we develop the equations that govern the shock front and discuss the physical parameters in section~\ref{sect:parameters}. In section~\ref{sect:results} we present our results. results and discuss implications in section~\ref{sect:discussion}.  We summarize this workand present our conclusions  in section~\ref{sect:conclusion}. section~\ref{sect:summary}.