deletions | additions       diff --git a/Three_sources_N62_1_N90_2_and__.tex b/Three_sources_N62_1_N90_2_and__.tex  index e3d2e01..904fabb 100644  --- a/Three_sources_N62_1_N90_2_and__.tex  +++ b/Three_sources_N62_1_N90_2_and__.tex 
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Three sources, N62_1, N90_2 and N117_3, have a non-gaussian line profile (see Fig. X). Each each case the line profile is stronger on the blue-side. The line-profile of N117_3 is double-peaked with the blue-shifted peak stronger than the red-shifted peak. The line-profiles of N62_1 and N90_2 are single-peaked but with plateau on the red-shifted side. We interprete these profiles as evidence of infall. Myers et al. (1996) present a model of infall that predicts similar line profiles. They assume two clouds (near and far) falling toward a common center and estimate the the resulting line profiles accounting for optical depth effects as well as standard radial-dependencies of velocity and excitation temperature. By measuring five parameters, the Myers et al. (1996) model allows as estimate of the infall velocity. The measured parameters are: $\sigma$ (velocity dispersion of an optically thin tracer), T_{BD} (the blue-shifted excess emission), T_{RD} (the red-shifted emission), T_D (the plateau emission), v_{red} (the red-shifted peak emission velocity) and v_{blue} (the blue-shifted peak emission velocity). When all quantities can be measured, the infall velocity is estimated to be:  \begin{equation}  v_{in} \approx \frac{\sigma^2}{v_{red} - v_{blue}} v_{blue}  ln\left( \frac{1+e T_{BD}/T_D}{1+e T_{RD}/T_D}\right) end{equation}