--plotting the critical ratio as a function of frequency in the band 22.0 Hz up to 23.0 Hz it can be seen that the worsening factor is of the order of 16% and a huge peak with two horns is clearly visible. It is also well visible plotting the energy. While in the persistency plot the disturbance is not visible, due to the varying frequency and the fact it is not always present
-- another point is that in the first 1.5 months of VSR2 the Vela frequency was exact in between the two
horns, which was "good" . Then the frequency of the disturbance, which was slowly increasing, started to coincide exactly with the VELA frequency (22.38 Hz).
- Thus our observation is that the frequency of this effect was increasing, and
looking at the graph attached here I have got the impression this is still true: the disturbance now is around 22.4...thus not at the Vela frequency but near enough to
create problems..
Pia