Results of the search for burst gravitational waves with the TAMA300 detector

The 9th Gravitational Wave Data Analysis Workshop (December 15-18, 2004, Annecy, France)

Results of the search for burst Results of the search for burst gravitational waves with the TAMA300 gravitational waves with the TAMA300

detector detector

Masaki Ando (Department of Physics, University of Tokyo)

and The TAMA Collaboration

The 9th Gravitational Wave Data Analysis Workshop (December 15-18, 2004, Annecy, France) 2

Target of this work … Burst gravitational waves

Predicted waveforms of stellar-core collapse 　　　TAMA300 data

Data Taking 9

Data analysis　　　 Excess power filter

Fake reduction

Galactic simulation 　 Signal injection simulation

Introduction Introduction

Upper limit for Galactic events 　　 Galactic event rate GW energy rate


OutlineOutline

Target waveform

TAMA300 data Overview, Observation runs, Noise level

Analysis schemeBurst filter, Fake reduction

Analysis resultsEvent-trigger rate

Galactic simulation

Summary and Conclusion


Analysis targetAnalysis target- Target waveforms -- Target waveforms -

Targets : Burst waves from stellar-core collapse

Common characteristics Short burst waves Spike wave ~1msec Duration time <30msecNot suitable for templates

(matched filtering: not available)

Numerical simulations … ~100 waveforms are obtained Not cover all initial conditions

H.Dimmelmeier et al, Astron. Astrophys. 393 (2002) 523.

0 10 20 30 40 50–1.5

–1

–0.5

0

0.5

1

1.5

Am

plitu

de [x

10–20 ]

Time [msec]

Gravitational waveformsfrom stellar–core collapse

(10kpc from the earth)

A1B1G1A3B3G1A4B1G2

Amplitude : h rss : 4 x 10-22 /Hz1/2 (at Galactic center: 8.5kpc)

Energy : E tot : 9 x 10-8 Moc2

Reference waveforms Relativistic, axisymmetric simulation by Dimmelmeier et al.

26 waveforms


TAMA300 (1)TAMA300 (1)- Overview -- Overview -

Data : Observation data by TAMA300

National AstronomicalObservatory at Mitaka, Japan

Baseline 300m

TAMA300, an interferometric GW detector in Japan Baseline length : 300m Fabry-Perot-Michelson interferometer with power recycling Placed at National Astronomical Observatory in Japan

Sufficient sensitivity for Galactic binary inspiralsAutomated crewless operation9 observation runs 　　 (Data : ~3000 hours)

First obs. run in 1999 (DT1)

Upgrade and observation runs


TAMA observation runs

TAMA300 (2)TAMA300 (2)- Observation runs -- Observation runs -

Data Taking ObjectiveObservation

timeTypical strain noise level

Total data(Longest lock)

DT1 August, 1999 Calibration test 1 night 3x10-19 /Hz 1/210 hours

(7.7 hours)

DT2 September, 1999 First Observation run 3 nights 3x10-20 /Hz 1/2 31 hours

DT3 April, 2000Observation with

improved sensitivity3 nights 1x10-20 /Hz 1/2 13 hours

DT4Aug.-Sept.,

2000100 hours'

observation data2 weeks

(night-time operation)1x10-20 /Hz 1/2

(typical)167 hours

(12.8 hours)

DT5 March, 2001100 hours' observation with high duty cycle

1 week(whole-day operation)

1.7x10-20 /Hz 1/2

(LF improvement)111 hours

DT6Aug.-Sept.,

20011000 hours' observatio

n data 50 days 5x10-21 /Hz 1/21038 hours(22.0 hours)

DT7Aug.-Sept.,

2002Full operation with

Power recycling2 days 25 hours

DT8Feb.-April.,

20031000 hours

Coincidence2 months 3x10-21 /Hz 1/2

1157 hours(20.5 hours)

DT9Nov. 2003 -Jan., 2004

Automatic operation

6 weeks 1.5x10-21 /Hz 1/2 558 hours(27 hours)


TAMA300 (3)TAMA300 (3)- Data Taking 9 -- Data Taking 9 -

TAMA DT9

0 200 400 600 800 1000 120010

–21

10–20

10–19

No

ise

Le

ve

l [1

/Hz1/

2 ]

Time [hour]

DT9

DT8DT6Noise floor level drift

Thu SunTueMon Fri SatWed

Observation (continuous over 10min)

Date and Time in JST (UTC +9 hours) 29

6

17

24

313029

22

15

11

Nov. 28, 2003

54

12

16

23 25

18

7

30

Dec. 1

8

19

26 27

20

139

2 3

10 14

21

28

Jan. 1 32 4

8 95 106 7 11

Data Taking 9 Nov. 28, 2003 – Jan. 10, 2004 558 hours of data　　 Noise level : 2x10-21 /Hz1/2

2nd half : 200 hours (Christmas, new-year Holiday terms) Better noise level Stable environment

This analysis …


TAMA300 (4)TAMA300 (4)- Noise spectrum -- Noise spectrum -

Noise spectrum TAMA noise spectrum with Dimmelmeier waveforms

102 10310–24

10–22

10–20

10–18

De

tec

tor

No

ise

Le

ve

l [

1/H

z1/2 ]

Frequency [Hz]

TAMA

LCGT design sensitivity

noise level(DT9)

GW

RS

S A

mp

litu

de

an

d

10kpc events

100pc events

Detectable range : ~ 300 pc (optimal direction, polarization)


Burst filter : Excess power filter

Burst-wave analysis (1)Burst-wave analysis (1) - Excess power filter - - Excess power filter -

2 3 4 5

–500

0

500

Am

plit

ud

e [

arb

. un

it]

Time [sec]

Burst signal

Noise + signalRaw Data (time series)

2 3 4 50

2

4

6

Tota

l p

ow

er

[arb

. u

nit

]

Time [sec]

Threshold

Total power in given T-F region

Few assumptions for signal … time-frequency bands

Robust for waveform uncertainties

Signal !!

Evaluate signal power in given time-freqency regions

Spectrogram

Freq. sum

Time- Frequency plane (spectrogram)


Burst-wave analysis (2)Burst-wave analysis (2) - Filter parameters - - Filter parameters -

Filter parameters (time-frequency window)

　　

t = 12.8 [msec] 　f = 2300 [Hz]

For higher SNR … Short time window

~Signal durationRequires line removal

Wide frequency window Limited by worse noise level at low and high freq.

10310–21

10–20

10–19

10–18

No

ise

le

ve

l [1

/Hz1/

2 ]

Frequency [Hz]200 500 2x103

Typical noise levels

DT6

DT8

Calibration peak

modepeaks

Violin

modepeaks

Violin

DT9

Burst GW → Short duration, wide frequency band

(c.f. Cont. waves: long duration, narrow freq. band)


10–6 10–5 10–4 10–3

10–22

10–21

10–20

10–19

10–18

No

ise

–le

ve

l d

rift

[

arb

. u

nit

]

Frequency [Hz]

Daily change (1.15x10–5 Hz)

DT9

DT8

Burst-wave analysis (3)Burst-wave analysis (3) - Data conditioning - - Data conditioning -

Data conditioning

Line removal Filter freq. resolution : ~80Hz　　　 line removal is required (AC line, Violin mode peak, Calibration peak)

102 103

10–21

10–20

10–19

10–18

10–17

Str

ain

no

ise

[1/

Hz

1/2]

Frequency [Hz]

Without Line Removal

With Line RemovalMethod FFT 72sec data Reject line freq. components Inverse FFT

Normalization Track the drift of noise level　　　 Each spectrum is normalized by averaged noise spectrum

Use 30min-averaged spectrum

30min(5.6x10-4 Hz)


Burst-wave analysis (4)Burst-wave analysis (4)- Fake reduction -- Fake reduction -

Fake reduction, Injection test　　

Veto with monitor channelsBurst signal < 100 msec

Most detector noises > a few seconds

Correlated bursts in

intensity monitor channel

Effective to long-duration noises

Time-scale selection

Two veto methods

Effective to short spikes

Less than 2%

Safety check : not to reject real signals Confirm that monitor channel bursts were not caused by real GW signal

Hardware and software injections

100 102 104 106

100

101

102

Po

we

r in

GW channel power (SNR)

Inte

ns

ity

mo

nit

or

ch

an

ne

l

veto threshold

Event threshold

Hardware injection results

DT8 analysis results (before veto)

False-dismissal rate estimation

Calibration : SNR (filter output) hrss


TAMA burst analysisTAMA burst analysis- Analysis results -- Analysis results -

Analysis results

Improvement in rates

with veto analyses

Better in DT9 than DT8

Fake rate : 30 –100 times

Sensitivity : 3-6 times

Still many fake events

Trigger rate with vetoes

100

101

102

103

104

105

106

10–6

10–5

10–4

10–3

10–2

10–1

100

Event Power Threshold (Pth)

Rat

e [

even

ts/s

ec]G

aussian

no

iseDT9

DT8

DT6

DT9 (before veto)

Much larger than results with Gaussian noise


Galactic simulation (1)Galactic simulation (1)- Simulation method -- Simulation method -

Galactic simulation

Monte-Carlo simulation　　 Random events　　 Inject signal to real data　　 Analyze data with same codes

Investigate ‘what happens with real signals’ compare with obs. results

101 102 103 104 105

10–6

10–4

10–2

100

Sta

rs w

ith

in t

he

Ra

ng

e (

rati

o)

Distance from the Sun [pc]

Position : Somewhere in Galaxy

dd h

z

R

Rexp

R = (x 2+y 2) 1/2

Rd : 3.5 kpc, hd : 325 pc

Exponential Disk model

Time ： Somewhere in DT9 (200hr) Detector angular depend. Source : 26 Dimmelmeier waveforms Random angle Source angular depend.

Effective distance

Galactic-event distribution


Galactic simulation (2)Galactic simulation (2)- Results -- Results -

Results of Galactic injection test

Event-selection threshold : SNR>2.9Detection efficiency : 1x10-5

Observation result : 7x10-2 events/sec

Galactic event rate

6 x 10–4 Moc 2/sec

GW energy rate 6 x 103 events/sec

(90% C.L.)

Upper limitAssume a Poisson distribution for the observed event number N obs N ul

100 101 102 10310–8

10–7

10–6

10–5

10–4

10–4

10–3

10–2

10–1

Event Power Threshold (Pth)

Rat

e

[eve

nts

/sec

]

(after vetos)

Gau

ssian n

oise

Galactic eventsEfficiency for

Det

ecti

on

eff

icie

ncy

Event rate in DT9

Threshold


SummarySummary

Burst-wave analysis with TAMA300 dataTAMA300 DT9, 200hours of dataExcess Power filter, Fake reductionGalactic event simulation (Simulated-signal injection test)

Too large for real events

Originate in residual fake triggers

Galactic event rate

6 x 10–4 Moc 2/sec

Galactic GW energy rate 6 x 103 events/sec

(90% C.L.)


ConclusionConclusion

Conclusion　　

Current worksTAMA detector improvement (Noise hunting, Better isolation)

Better filter (Filter tuning, better burst filter)

Coincidence analysis (LIGO, ROG)

This work … Scheme to set upper limits for Galactic events from observation data

We need …More realistic waveform catalogMore realistic Galactic modelNext-generation detector to cover our Galaxy (Ad-LIGO, LCGT)


　　　　　　　　　　　　　　　 End

Results of the search for burst gravitational waves with the TAMA300 detector

Documents

Transcript of Results of the search for burst gravitational waves with the TAMA300 detector