Looking through the spectrogram of LSC_DARM we see a few lines disappear during the A/C switch off. Most of these 'lines' are farily broad small bumps in DARM. Correlating the time of the disappearance of lines with the switch OFF times. We can make the following correlations

• @10:43LT 6.5Hz disappears (figure 1) -> 6.5Hz is a result of the UTA Hall A/C
• @10:38LT 24.6Hz disappears (figure 2) -> 24.6Hz is a result of the DAQ A/C
• @10:05LT 36.3Hz disappears (figure 3) -> 36.3Hz is the Photon Calibration Line 
• @11:01LT 207Hz disappears (figure 4) -> 207Hz is a result of the second splitter (inj ele-room) //could also be the UTA A/C (laser lab), seems to be very high in frequency though

Asside from these lines there seems to be no other obvious lines that disappear. It is worth noting that in these are all relatively small bumps, with the exception of the Photon Calibration LIne.