deletions | additions       diff --git a/Windspeed.tex b/Windspeed.tex  index 79c8d64..584ad21 100644  --- a/Windspeed.tex  +++ b/Windspeed.tex 
...
\subsection{Wind speed}  The launching mechanism of the stellar wind in CTTS is uncertain. \citet{2007IAUS..243..299M} show that stellar winds from CTTS cannot have a total mass loss above $10^{-11}M_\odot\mathrm{ yr}^{-1}$ if they are launched hot. Otherwise, the high densities required to reach such a mass loss would lead to a runaway cooling.   This should be observable and would probably hinder the wind launching. Thus, the winds of CTTS are probably more complex than just a scaled up version of the solar wind. Still, the wind speeds observed in the sun provide a reasonable estimate for $v_\infty$.For a solar-type wind, it is not unreasonable to expect similar wind speeds.  The solar wind consists of a slow wind with a typical velocity of 400~km~s$^{-1}$ and a fast wind around 750~km~s$^{-1}$ \citep{2005JGRA..110.7109F}. The relative contribution and the launching position of the two types changes over the solar cycle, but the slow wind often emerges from regions near the solar equator and fast wind is generally associated with coronal holes \citep{1999GeoRL..26.2901G,2003A&A...408.1165B,2009LRSP....6....3C}. Despite these differences, the total energy flux in the solar wind is almost independent of the latitude, because the slower wind is denser than the faster wind \citep{2012SoPh..279..197L}. In this article, we set $v_\infty=500$~km~s$^{-1}$ as the fiducial outflow velocity and we assume that the wind is accelerated close to the star and has reached $v_\infty$ before it interacts with the shock front. We use a spherically symmetric stellar wind with a constant velocity. For a solar-type wind this works well for deriving the shape of the shock front because eqn.~\ref{eqn:r0} contains the kinetic energy density $\rho v^2_\infty \propto \dot M v_\infty$.