Our monitoring of the omiscans for the top BBH/BNS triggers has turned up some interesting glitches from October 30 and 31 at the Hanford detector. First off, we have the following scan vetoed by the UPV, demonstrating solid UPV performance:

https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct30/BBH/GW/1130235508/
https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct30/BBH/1130235508/#H1:ASC-Y_TR_A_NSUM_OUT_DQ

A few interesting things to note here: the signal on the vetoed channel is clearly visible in the CALIB_STRAIN scan, however the signal is moved to a higher frequency. Secondly, the cause of the loud glitch signal at lower frequency is unclear, although there is some potential connection to other auxiliary channels.

Next we have another loud glitch signal showing up in the CALIB_STRAIN channel, however the veto seems to have failed here:

https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct31/BBH/GW/1130327173/
https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct31/BBH/1130327173

This time is indeed vetoed, however the veto channel was not strong enough to be mapped (SNR threshold set at 6). Even so, there is clear correlation between the CALIB_STRAIN signal and a number of auxiliary channels. It’s worth noting that there are loud signals across a good many of channels (and a couple different types of detectors) at this time. This scan is abnormally noisy in general.

Here we have a glitch in CALIB_STRAIN with a strong connection to a particular auxiliary channel, missed by the UPV:

https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct31/BBH/GW/1130326931/
https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct31/BBH/1130326931/#H1:ASC-REFL_A_RF45_Q_PIT_OUT_DQ

As can be seen in the uniform signal across the auxiliary channels, there was a very loud, intermittent event here that was detected by a great number of different auxiliary detectors.

There is an interesting glitch here with an unclear cause:

https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct31/BNS/GW/1130314219/

And finally the big glitch that we have been chasing the past few days was seen again:

https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct30/BBH/GW/1130226154/
https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/Oct30/BBH/1130226154/#H1:PEM-EY_MAG_EBAY_SUSRACK_X_DQ

We know this glitch is correlated with the following channel, however we believe that channel to be simply reacting to the same thing that is causing the glitch, and that the true cause lies elsewhere. We will continue to update as we try to isolate the root issue. For further viewing of the daily omiscans, view the calendar page here:

https://ldas-jobs.ligo-wa.caltech.edu/~jacob.broida/ResultsCalender.html