Thats very interesting, as it shows a bandwidth totalling 1 MHz
rather than the very limited few kHz of PC displays.

It is a very useful plot because it tells us the residual carrier power as
a proportion of the total TX power

You can clearly see that the data is modulated onto a ~260 kHz subcarrier,
and there is residual carrier in the middle.  The data rate appears to be
60 kbps.  The resolution bandwidth is 3 kHz, so the total power in the
sidebands is 2 x 60/3 = 40:1 or 16 dB compared with the sidelobe's displayed
level.  The carrier is at +6 dB compared with the sideband peak, and therefore
at 6 - 16 = -10 dB compared with the total sideband power.

That is, ~91% of the power is in the sidebands, and ~9% in the residual
carrier.

I have also analysed an audio file from Charlie G3WDG, and was able to
estimate the Rosetta carrier e.i.r.p.  Actually it has a 2.2m dish and the 
TX power is 28 W max.