In addition to the 1.23Hz line seen in DARM from ETMX ISI (alog 73625), there is another line closeby at 1.39Hz (seen in plots attached to 73622) which is coming from ITMY ISI (as reported by Jim here). It is also visible on the BS ISI sensors, but it is probably being fed from the ITM to the BS via the CPS diff loop. The attached plot on p1 shows the stage 2 ISI dofs in the beam direction where we see the 1.23Hz line in ETMX (green) and 1.39Hz line in the BS and ITMY (blue and cyan). p2 shows DARM IN1, p3 shows the coherence between DARM and the ISI and p4 is the zoomed in coherence version between 1-2Hz, where we can see coherence between BS/ITMY and DARM at 1.39Hz. ETMY is also coherent, which I presume is because the ITMY motion is fed to ETMY also via CPS diff. 

While we look at ETMX tomorrow during maintenance, I would also be interested to take some data with the ITMY ISI offline.