for the Collaboration

GWDAW 2005

Status of inspiral search in C6 and C7 Virgo data

Frédérique MARION

GWDAW 2003 2

C6 & C7 runs

C6 14 days 86% duty cycle

(in science mode) Factor 2 variation in

the horizon over the course of the run

C7 5 days 65% duty cycle Detector sensitivity

also not stationary

Optimally oriented [1.4,1.4] M (SNR=8)

GWDAW 2003 3

Inspiral online analysis

Both pipelines, Merlino and MBTA, ran online during C6 and C7, getting data from online h-reconstruction Monitoring information provided

» Lists of loudest events» Plots for monitoring web pages

MBTA

Hardware injections

GWDAW 2003 4

C6 hardware injections

56 inspiral hardware injections 4 different periods, [1.4,1.4] M, SNR ranging from ~15 to 25

All detected Check timing and mass estimation accuracy Check SNR recovery

~ 10% loss might be due to sensitivity non-stationarityMBTA

GWDAW 2003 5

C7 hardware injections

2 periods of inspiral injections [1.32 , 1.36] M, SNR ~ 20

Detected with good accuracy Issue with some injections having a bad 2

» under investigation

Merlino

GWDAW 2003 6

Smaller variations still present

Non-stationarities: C6

Evolution in time of the frequency at which half of the SNR is integrated Change in the shape of the PSD

± 10% variations on short time scales (~15 min)

GWDAW 2003 7

Non-stationarities: C7

Variations of the PSD on short time scales not obvious to follow with adaptive mechanisms

Same kind of variations observed in C7

GWDAW 2003 8

C6 analysis: quality cuts (I)

C6 first six days Horizon very unstable “Bump” going up and down in 100-300 Hz

region of sensitivity curve (stray beam) Leave this first part of the run aside

Focus on remaining 8 days

Dark fringe spectrum

GWDAW 2003 9

C6 analysis: quality cuts (II)

Skip first five minutes after relock

Use auxiliary channels to identify obvious sources of high SNR triggers, e.g. Saturations in frequency

stabilization loop Glitches on actuator coil

drivers

GWDAW 2003 10

C6 analysis: SNR distribution

[0.9 - 3] M analysis ~ 170 hours of data

Very loud events eliminated by basic quality cuts

Tail of distribution still extends to high values Even strong, the hardware

injections (in red) do not dominate the noise

MBTA

Inspiral injectionsBurst injections

GWDAW 2003 11

MBTA

C7 analysis

[0.9 - 3] M analysis ~ 80 hours of data

C7 SNR distribution slightly better than C6

Merlino

A relatively quiet 10 hours

long period

GWDAW 2003 12

C7 software injections

Systematic studies (efficiency, 2 test) with Merlino on software injections performed during C7 quiet period see poster by L.Bosi

GWDAW 2003 13

hardware injection

noise event

C6: a posteriori vetoes

SNR distribution between low and high frequency bands 2

2 bands

noise event

Shawhan-Ochsner veto Look at output of matched

filter in time domain

GWDAW 2003 14

22 bands < 100

Samples above threshold < 30

Samples above threshold < 30

22 bands< 100

C6: SNR with vetoes

Bulk of distribution unchanged

High SNR tail definitely improved Hardware injections

almost stand out

GWDAW 2003 15

C7: vetoes

Behavior similar to C6

GWDAW 2003 16

C7: SNR with vetoes

Loudest surviving event has SNR < 20

22 bands < 40

Samples above threshold < 30

Samples above threshold < 30

22 bands< 40

GWDAW 2003 17

Conclusion

C6 and C7 data have extra-galactic sensitivity to neutron star inspirals

Not science quality data Detector behavior glitchy and not stationary

Preliminary analysis Two pipelines operational for online and offline analysis Hardware injections, quality cuts, a posteriori vetoes

Pursue investigations Learn as much as we can from those data in order to get prepared

for the science data to come next year