1. LIGO-G030412-00-D S2 Glitch Investigation Report Laura Cadonati (MIT) on behalf of the Glitch Investigation Team LSC meeting, August 2003, Hannover

2. LIGO-G030412-00-D Hannover LSC meeting - August 18,20032 Glitch Investigation MIT: Adikhari, Ballmer, Cadonati, Desai, Katsavounidis SYRACUSE: Bernstein, Dalrymple, Di Credico, Frei, Magri, Saulson CIT: Shawhan, Zweizig LSU/LLO: Gonzalez, Franzen, Zotov OREGON: Ito, Schofield CARLETON: Christensen, Steussy FLORIDA: Klimenko PSU: Ashley identification of S2 outliers (> 4-5 sigma) starting from the online DataBase population. statistical description of glitches (function of channels, thresholds, filters…) correlation of glitches among channels and with AS_Q definition of segments with unacceptable glitch rates identification of a usable veto for the Burst and Inspiral analysis groups PartecipantsGoals http://ligo.mit.edu/ldas/dc/index.html

3. LIGO-G030412-00-D Hannover LSC meeting - August 18,20033 H1 (MIT) Analyzed 10 channels with most triggers in the DataBase (online production) for ALL S2 Compared to the glitches found in AS_Q by the same algorithm glitchMonMICH_CTRL Tr_10_15 30 Hz HPAS_I Tr_6_8 30 Hz HP AS_Q Tr_6_8 30 Hz HP 156,402 events in 1039.24 h efficiency=6.9% 96.6% veto success efficiency=6.7% 71.4% veto success Also interesting: POB_Q (90% overlap with AS_Q, 0.6% veto efficiency, peak in lag plot) Others: AS_DC, POB_I, REFL_Q, PRC_CTRL (less than 30% overlap with AS_Q, but good lag plots) Lag plot and amplitude scatter plot for MICH_CTRL vs AS_Q DeadTimes < 0.1% Found ~ 4000 simultaneous glitches on AS_Q, MICH_CTRL, AS_I (POB_Q?)

4. LIGO-G030412-00-D Hannover LSC meeting - August 18,20034 Next step: compare to Burst trigger candidates in the S2 playground (single IFO lock list). NOTE the importance of frequency of burst events!!! ALSO: there is poor overlap (few %) between Burst candidates (>100Hz) and glitchMon triggers (>30Hz) H1 (MIT)

5. LIGO-G030412-00-D Hannover LSC meeting - August 18,20035 Nothing interesting seen for TFCLUSTERS events below 1kHz »TFCLUSTER’s thresholds might be too low for this study - now repeating with higher thr. For TFCLUSTERS events in 1-3kHz (broadband glitches): »Low efficiency (~0.2%) and deadtime (< 0.1%) but interesting lag plots (peaks at 0 lag, low statistics…): MICH_CTRL AS_I AS_DC POB_Q For the EXCESS POWER events in 160-670 Hz »Low efficiency (0.2-0.6%) and deadtime (0.01%), zero lag peak: AS_DC POB_Q In progress right now for H1… GlitchMon reruns on MICH_CTRL, AS_I, AS_DC, POB_Q at 3 threshold settings, with 30, 70, 100 Hz high pass and production of efficiency vs deadtime plots. More channels will follow. H1 (MIT) For more details on the H1 investigation see Erik Katsavounidis’ talk in Wednesday afternoon DC session

6. LIGO-G030412-00-D Hannover LSC meeting - August 18,20036 H2 (MIT) Analyzed 17 channels with most triggers in the DataBase (online production) Compared to the glitches found in AS_Q by the same algorithm glitchMon: 40,831 triggers in 818 hours MICH_CTRL: 0.4% dead time, 50.4% overlap with AS_Q and 44.1% veto efficiency Comparable performance in: AS_I PRC_CTRL POB_Q Also interesting (good lag plots!): »REFL_Q »POB_I »ASC-WFS1_QP »ASC-WFS1_QY »ASC_QPDY_DC »ASC_QPDX_DC »AS_DC Lag plot for MICH_CTRL vs AS_Q

7. LIGO-G030412-00-D Hannover LSC meeting - August 18,20037 When comparing to Burst candidates in the playground: Low efficiency (<4%) and deadtime (< 0.1%) but interesting lag plots: »AS_I » MICH_CTRL »AS_DC » PRC_CTRL H2 (MIT) For more detail on the H2 investigation, see Erik Katsavounidis’ talk in Wednesday afternoon DC session

8. LIGO-G030412-00-D Hannover LSC meeting - August 18,20038 Analyzed coincidences between AS_Q signals and auxiliary channels as seen by zGlitch and glitchMon (using online production in the playground): »Best candidates: »LSC-MICH_CTRL  zGlitch:  46%, deadtime=0.2) »LSC-AS_I (**)  zGlitch:  45%, deadtime=0.4%) (**)probably unsafe »LSC-POB_Q  glitchMon:  9.6%, deadtime=0.2%; ) L1 glitches in the playground (Syracuse) Same analysis performed on ETG triggers (TFCLUSTER) against auxiliary channels as seen by zGlitch and glitchMon

9. LIGO-G030412-00-D Hannover LSC meeting - August 18,20039 TFCLUSTERTotal 0-100Hz 100-400Hz 400-800Hz800Hz + Singles 414497 16311 20770 9736 374425 Clusters 101967 14694 14683 6922 82875 EFFICIENCY zGlich vetos Total 0 – 100 Hz100 - 400 Hz 400 – 800 Hz > 800 Hz LSC-MICH_CTRL 2.4% 1.4% 1.5% 4.7% 2.7% LSC-AS_I 7.0% 4.8% 6.0% 11.7% 7.9% glitchMon Total 0 – 100 Hz100 - 400 Hz 400 – 800 Hz > 800 Hz LSC-MICH_CTRL 2.1% 3.1% 3.7% 4.7% 1.9% LSC-AS_I 1.9% 1.3% 1.4% 1.8% 2.1% ASC-QPDY-DC 4.4% 3.6% 4.1% 5.1% 4.6% For more detail, see: Syracuse web page at: http://www.physics.syr.edu/research/relativity/ligo/http://www.physics.syr.edu/research/relativity/ligo/ Alessandra Di Credico’s talk in Wednesday afternoon DC session Best candidates are still LSC-MICH_CTRL and LSC-AS_I for both zGlitch and glitchMon L1 glitches in the playground (Syracuse)

10. LIGO-G030412-00-D Hannover LSC meeting - August 18,200310 Veto safety studies (Ito, Schofield) H1 The position of this cut Is not decided yet! do not allow veto Study veto safety with hardware injections

11. LIGO-G030412-00-D Hannover LSC meeting - August 18,200311 WaveMon looks at coincidence of AS_Q channel and an auxiliary channels and produces a pair of triggers (VETO and ASQ) in all S2 MC_F, MICH_CTRL, REFL_I, REFL_Q POB_I, POB_Q, LVEA_V1, MAG1X, SEISX WaveBurst web page at http://www.phys.ufl.edu/LIGO/bursts/wavemon/S2.html http://www.phys.ufl.edu/LIGO/bursts/wavemon/S2.html Sergei Klimenko’s talk in Wednesday afternoon DC session WaveMon (S. Klimenko) off-time 15 sec lag on-time Dead times: H1: 2% H2: 1% L1: 2.5% L1:LSC-MICH_CTRL ASQ log(CL) VETO log(CL)

12. LIGO-G030412-00-D Hannover LSC meeting - August 18,200312 WaveMon (S. Klimenko) Time lag [s] L1 HW injections Used hardware injections to look for cross coupling between AS_Q and veto channels Select qualified triggers by setting a threshold on strength of veto clusters. »Lost <4% waveMon AS_Q triggers with this cut In Progress:  Re-run WaveMon on-line on larger number of channels and wider frequency band.  Study of veto efficiency ASQ VETO

13. LIGO-G030412-00-D Hannover LSC meeting - August 18,200313 Coherence studies (N. Christensen, D. Steussy) Looking at coincidences between inspiral candidates and aux channels L1:SUS-ITMX_OPLEV_POUT L1:SUS-ITMX_OPLEV_YOUT Observed coincident glitches AND coherence increase between 50 and 200 Hz 80 sec before the glitch: Coherence plot between ASQ and ITMX_YOUT During the glitch: Coherence plot between ASQ and ITMX_YOUT (16 sec)

14. LIGO-G030412-00-D Hannover LSC meeting - August 18,200314 Coherence increase observed during hardware injections too!  Worry about safety… For more information: http://physics.carleton.edu/Research/ligo/7-10/S2noiseb.html Nelson Christensen’s talk in Wednesday afternoon DC session Coherence studies (N. Christensen, D. Steussy)

15. LIGO-G030412-00-D Hannover LSC meeting - August 18,200315 Glitch tracking (Zotov) Tracking foot stomps in the control room through the interferometer »Glitches appear on AS_Q clearly at low frequencies, and possibly in 100-300Hz as well (bleeding from lower frequencies) »http://www.ligo-la.caltech.edu/~nzotov/glitch_investigations/glitchTrack.html Also checking 10 loudest inpiral candidates in the S2 playground against various aux channels – nothing big found. »http://www.ligo-la.caltech.edu/~nzotov/glitch_investigations/glitch.html

16. LIGO-G030412-00-D Hannover LSC meeting - August 18,200316 LineAmp - (Ashley, Finn) Tracks the calibration line amplitude and phase by heterodyning the AS_Q against a local (software) oscillator operating at the line frequency. Samples are averaged over a specified interval. Coded in MATLAB and produces eps plots of the amplitude and phase and saves trend files (available online). http://gravity.psu.edu/~ashley/LSC/LineAmp LineAmp (PSU)

17. LIGO-G030412-00-D Hannover LSC meeting - August 18,200317 Summary The pursue of glitches is ongoing – so far analyzed only interferometer channels »MICH_CTRL, AS_I, POB_Q, AS_DC »Testing validity of these channels as vetos for Burst and Inspiral analysis Performing reruns of AS_Q and AUX channel glitch search »different methods Veto safety tested with hardware injections Next: PEM channels » lots of work still needed …