Several additional paragraphs have been added near the figures to help explain the plots appearing in these figures. For the stationary atom case, the limits on y_{m0} are determined from inequality (106) and it is indeed possible for y_{m0} to be less than y_{min}. The manner in which we arrived at the regions of validity of the approximations is now described in more detail.
The paper contains only one figure with 28 panels presenting the results of the calculations. I think that this figure is very difficult to read! I do not understand clearly why results are plotted with y < y_min if this not physical: please explain!