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LIGO-G050642-00-Z LIGO data analysis status Michael Landry LIGO Hanford Observatory for the LIGO Scientific Collaboration http://www.ligo.org PAC19 Dec 12, 2005 LIGO Hanford Observatory RX J1856.5-3754, neutron or strange quark star at d=117pc Credit: NASA/SAO/CXC/J.Drake et al.
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LIGO-G050642-00-Z Landry - PAC19 2 Overview Sources S2, S3, S4 results from the four search groups »All searches: no detections yet S5 online
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LIGO-G050642-00-Z Landry - PAC19 3 Compact binary systems »Neutron stars and black holes »Inspiral and merger »Probe internal structure, populations, and spacetime geometry Supernovae, GRBs »all-sky untriggered searches »burst signals in coincidence with electromagnetic and/or neutrino observations Stochastic background »Cosmological relic »Superposition of astrophysical sources Spinning neutron or quark stars »Known compact spinning stars, LMXBs »all-sky search for unknown objects (computing challenge) Astrophysical sources of gravitational waves
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LIGO-G050642-00-Z Landry - PAC19 4 Signal duration and template Short durationLong duration no matched filter Burst searchStochastic search matched filter Inspiral searchCW search
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LIGO-G050642-00-Z Landry - PAC19 5 Search groups LSC partitioned into four search groups 2 Co-chairs (one theory, one experimental) Mix of LIGO Lab and LSC representation, theorists, phenomenologists and experimentalists in each group
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LIGO-G050642-00-Z Landry - PAC19 6 Burst group efforts Expected waveforms too numerous and complicated to calculate for matched filter analysis Potential sources »supernovae, astrophysical phenomenae that power GRBs »mergers of compact objects »cosmic string cusps and kinks »disruptions of neutron stars Search for untriggered bursts »Triggers, vetoes, upper limits »Injections of simulated waveforms »Multiple event trigger generator (ETG) investigations Search for triggered bursts Other work »Cosmic string search »Inspiral-burst-ringdown search »LIGO-TAMA joint analysis of S2 »LIGO-Virgo working group struck
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LIGO-G050642-00-Z Landry - PAC19 7 S2 untriggered burst search bursts less than 1s, in band 100-1100Hz 9.98d of data analyzed – improved sensitivity of machine and in analysis pipeline Event triggers generated on triple-coincidence data, followed up by “r-statistic” waveform consistency test Background set by similar analysis with time-shifted data Set limit on rate of detectable gravitational wave bursts Test efficiency of pipeline to detect particular waveforms: both ad hoc (gaussian, sine-gaussian) and astrophysically-motivated waveforms (core-collapse and binary black hole) applied Set rate vs strength exclusion regions for these waveforms
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LIGO-G050642-00-Z Landry - PAC19 8 S2 untriggered burst search
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LIGO-G050642-00-Z Landry - PAC19 9 GRB 030329, confirmed supernova at z~0.17, or ~ 800Mpc away H1, H2 were in operation during S2. A targeted search resulted in no detection HETE S2 triggered burst search
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LIGO-G050642-00-Z Landry - PAC19 10 Stochastic group efforts Cosmological relic, or, summation of noise sources from astrophysical epoch Cross correlate detectors: uncorrelated noise integrates away while the signal to noise integrates up as the square root of time Make use of optimal filter, which includes overlap reduction function Searches include »LHO-LLO »H1-H2 »LLO-Allegro GW is the gravitational wave energy density per logarithmic frequency interval, divided by c, the energy density required to close the universe
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LIGO-G050642-00-Z Landry - PAC19 11 S3 S3 stochastic background results
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LIGO-G050642-00-Z Landry - PAC19 12 Inspiral group efforts predicted BNS inspiral rates »theoretical upper bound of 1/3 per year for LIGO S5 (Kalogera et. al, Ap J Lett 601, L179 (2004)) »n.b. higher rates predicted for initial LIGO, based on identification of short GRBs as binary inspirals (astro-ph/0511254) predicted BBH inspiral rates »theoretical upper bound of 1 per year for LIGO S5 Matched template analysis BNS BBH Primordial black holes High mass ratios, spin LIGO-Virgo LIGO-TAMA
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LIGO-G050642-00-Z Landry - PAC19 13 No detection. Simulations from up to 1.5 Mpc away were “detected” in S2. Effective distance of sources considered, and cumulative number of galaxies searched for in S2. S2 binary neutron star search
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LIGO-G050642-00-Z Landry - PAC19 14 S2 binary neutron star search False alarm coincident triggers, and simulated injections Rate < 47 per year per Milky Way-like galaxy Triggers generated when event passes SNR cut Chisquare test applied Intersite coincidence
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LIGO-G050642-00-Z Landry - PAC19 15 Continuous waves search group efforts Known pulsar »Coherent time-domain method –Target known isolated and binary neutron stars –Pulsar timing provided by Jodrell Bank Pulsar Group »Markhov-Chain Monte Carlo method Incoherent methods »Multiple methods (Powerflux, Stackslide, Hough) to test robustness and make crosschecks »All-sky searches and quick passing of data »Incoherent step in heirarchical search Coherent frequency-domain (“F-statistic”) searches »Search for LMXBs »Isolated all-sky, wide-parameter searches –Best for blind search –Coherent step in heirarchical search »Einstein@home: distributed computing effort
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LIGO-G050642-00-Z Landry - PAC19 16 S3, S4 time-domain preliminary results for known neutron stars Closest to spin-down upper limit »Crab pulsar ~ 2.5 times greater than spin-down (f gw = 59.6 Hz, dist = 2.0 kpc) »h 0 = 3.5x10 -24, = 1.9x10 -3 »Assumes I = 10 38 kgm 2 Best limit on one pulsar below 1x10 -6 Crab pulsar NASA/CXC/SAO Pulsar timing : Jodrell Bank Pulsar Group
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LIGO-G050642-00-Z Landry - PAC19 17 S2 Hough transform search Semi-coherent method Wide-parameter space 200-400Hz, one spindown parameter Hough transform is applied to find pattern produced by Doppler shift and spindown of gravitational wave signal to the time-frequency plane of the data 95% confidence upper limits on h0, over whole sky and different spindown values in 1Hz bands are shown Outliers: known instrument artifacts, or, not in triple coincidence
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LIGO-G050642-00-Z Landry - PAC19 18 GEO-600 Hannover LIGO Hanford LIGO Livingston Current search point Current search coordinates Known pulsars Known supernovae remenants User name User’s total credits Machine’s total credits Team name Current work % complete Einstein@home
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LIGO-G050642-00-Z Landry - PAC19 19 Final S3 analysis results Data: 60 10-hour stretches of the best H1 data Post-processing step on centralized server: find points in sky and frequency that exceed threshold in many of the sixty ten-hour segments analyzed 50-1500 Hz band shows no evidence of strong pulsar signals in sensitive part of the sky, apart from the hardware and software injections. There is nothing “in our backyard”. Outliers are consistent with instrumental lines. All significant artifacts away from r.n=0 are ruled out by follow-up studies. WITH INJECTIONS WITHOUT INJECTIONS
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LIGO-G050642-00-Z Landry - PAC19 20 Instrument artifacts Some instrument lines permanent features, others can be mitigated, e.g. violin resonances and 1Hz lines, respectively S4 Einstein@home search notches both classes of lines
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LIGO-G050642-00-Z Landry - PAC19 21 S2, S3 analysis papers Upper Limits on Gravitational Wave Bursts in LIGO’s Second Science Run, Phys Rev D 72, 062001 (2005) A Search for Gravitational Waves Associated with the Gamma Ray Burst GRB030329 Using the LIGO Detectors, Phys Rev D 72, 042002 (2005) Upper Limits from the LIGO and TAMA detectors on the rate of gravitational-wave bursts, gr-qc/0507081, accepted for publication in Phys Rev D Upper limits on a stochastic background of gravitational waves, Phys Rev Lett 95, 221101 (2005) Search for gravitational waves from galactic and extra–galactic binary neutron stars, Phys Rev D 72, 082001 (2005) Search for Gravitational Waves from primordial black hole binary coalescences in the galactic halo, Phys Rev D 72, 082002 (2005) Search for gravitational waves from binary black hole inspirals in LIGO data, gr- qc/0509129, submitted to PRD Limits on Gravitational-Wave Emission from Selected Pulsars Using LIGO Data, B. Abbot et al., LIGO Scientific Collaboration; M. Kramer and A. G. Lyne, Phys Rev Lett 94, 181103 (12 May 2005) First all-sky upper limits from LIGO on the strength of periodic gravitational waves using the Hough transform, Phys Rev D 72, 102004 (2005) To be submitted to gr-qc on the near horizon: S2 joint LIGO-TAMA search for binary neutron stars, and, S2 coherent wide-parameter search for gravitational waves: all-sky and Sco X-1 Plus! Many technical papers on techniques, status etc.
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LIGO-G050642-00-Z Landry - PAC19 22 S5 S5 analyses online or near-online »Precision calibration in place: S5 V1 quality as good or better than the S4 V4 (final) calibration »h(t) to be produced online »Stochastic and CW searches fast-tracked (weeks-months), burst and inspiral searches in true real time Stochastic search »Accumulated sensitivity calculated weekly »Fast-track H1-L1 search CW search »Fast-track time-domain search for known objects, update monthly »Incoherent searches to scan weekly for new line artifacts, and make blind, all-sky searches on months of data »Goal: deep, wide-band, blind search, heirarchical employing Einstein@home
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LIGO-G050642-00-Z Landry - PAC19 23 S5 Burst search »Fast track triggered searches, and high-threshold searches for gold-plated events. Deeper searches offline. Realtime injections. Inspiral search »Fast track BNS and BBH searches. Realtime triggers in control room (10m). Coincidence, chi-square later (2h). Realtime injections
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