Virgo Logbook

As Paolo reported, the WI payload got excited resulting in the excitation of structures between 14Hz and 80Hz (see also Figure 1). By comparing the excited data with 5 minutes of data before the excitation, using the maximum feasible resolution of ~100s (10mHz), we get a list of frequency of modes of WI payload, and (more important) we find that a few (3) of these are present in the quiet sensitivity curve.

Symbol (#) indicates that the noise is visible in the (10mHz) sensitivity.
Freq (Hz)
14.78 # (previously identified as WI RM vertical mode, see Marzia) (Figure 2)
37.41 (Figure 3)
40.033 # (Figure 4)
46.026 # (Figure 5)
46.845 (Figure 5)
54.85 (BROAD bump)
65.6
69.97
71.71 (Figure 6)
73.61 (Figure 6)
75.64 (Figure 6)

Note that a small line is present in the sensitivity at 46.86Hz (Figure 5) which, for analogy, we might suspect it is a mode of NI or NE or WE payload.