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Final Thoughts and Highlights Barry C. Barish Caltech Amaldi-6 Okinawa 24-June -05. LISA. Towards Detection of Gravitational Waves. From LISA Concept Demonstrations Mission From Bars Bars with Increased Bandwidth Spheres
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Final Thoughts and HighlightsBarry C. BarishCaltechAmaldi-6Okinawa24-June-05 LISA
Towards Detection of Gravitational Waves • From LISA Concept Demonstrations Mission • From Bars Bars with Increased Bandwidth Spheres • From Interferometers Advanced Interferometers Next Generation (QND) Detectors • From 8 Mpc (NN inspiral) 200 Mpc and then beyond • From Upper Limits Searches Detections • From Generic Searches Searches with Specified Waveforms • From Single Detectors Global Networks Amaldi-6 - Barish
Gravitational Waves in Space LISA Three spacecraft, each with a Y-shaped payload, form an equilateral triangle with sides 5 million km in length. Amaldi-6 - Barish
LISA Amaldi-6 - Barish
LISA Amaldi-6 - Barish
LISA Amaldi-6 - Barish
WD-WD, WD-NS, NS-NS binaries with GW frequency within LISA band are observed.These sources are GUARANTEED Distribution of WD binaries (Nelemans et al) Total number of detatched binaries 208736473 Total number of interacting binaries 34291253 Amaldi-6 - Barish Krolak
Data Analysis Issues Stochastic signal Interacting signals Isolated signals TDI Long wavelength regime Short wavelength regime LISA motion; long observation times; network of detectors Amaldi-6 - Barish Krolak
LISA Amaldi-6 - Barish
LISA The diagram shows the sensitivity bands for LISA and LIGO Amaldi-6 - Barish
10-18 10-20 10-22 10-24 DECIGO Bridges the Gap The Japanese Space Gravitational Wave Antenna - DECIGO Deci-hertz Interferometer Gravitational Wave Observatory LISA Terrestrial Detectors (e.g. LCGT) Strain [Hz-1/2] DECIGO 10-4 102 100 104 10-2 Frequency [Hz] Amaldi-6 - Barish
Sensitivity of DECIGO Force noise= 1/100 of LISA’s Amaldi-6 - Barish
Resonant Bar Detectors MiniGrail The Netherlands Auriga, Italy Allegro USA Future Schenberg Brazil Nautilus, italy Future Explorer Switzerland Niobe Australia Amaldi-6 - Barish
“spheres” • omnidirectionality: decode the excitation of the 5 • quadrupolar modes to get uniform sky coverage • & find direction of propagation • cross section: larger as the volume fill-up factor in • respect to bars MiniGRAIL (Leiden-Rome) just started operation Talks of Annette de Waard and Luciano Gottardi Schenberg (Brasil) coming to Amaldi-6 - Barish
DUAL: two nested resonant masses Cerdonio et al PRL (2001), Bryant et al PRD (2003), Bonaldi et al PRD (2003) read-out with non-resonating transducers the differential deformations at frequencies between the lowest quadrupolar modes GW signals add back action noises subtract talk by Michele Bignotto sensitive in a few kHz-wide freq band !!!
sensitivities in the 2006 - 2012 prospective Amaldi-6 - Barish
International Gravitational Event Collaboration (IGEC) • ALLEGRO,AURIGA,EXPLORER, NAUTILUS, and NIOBE 1997-2000. • The search for burst waves at resonant frequency ~ 900 Hz. • The detectors nearly parallel to maximize coincident sensitivity. • Candidate events at SNR > 3-5 (~background events 100/day) • Data exchanged: peak amplitude, time of event and uncertainties. • Threshold equivalent to ~0.1 M⊙ converted into a gravitational wave millisecond burst at a distance of 10 kpc. • The accidental coincidence rate over 1 sec interval (e.g. bandwidth of 1 Hz) was ~ few/week two-fold and ~few/century three-fold. • Time resolution not sufficient to resolve incident wave direction, no directional search has been applied. • No evidence for grav wave bursts was found. Amaldi-6 - Barish
IGEC coincidence search Upper Limit on the Rateof gravitational waves bursts from the GALACTIC CENTERrandom arrival times and amplitude search threshold h Final results rate [y –1] The Area above the blue curve is excluded with a coverage > 90% search threshold h h~ 2 10-18 DE ~ 0.02 M⊙ converted @ 10 kpc Amaldi-6 - Barish [P. Astone, et al. Phys. Rev. D68 (2003) 022001]
EXPLORER-NAUTILUS 2001 During 2001 EXPLORER and NAUTILUS were the only two operating resonant detectors, with the best ever reached sensitivity. An algorithm based on energy compatibility of the event was applied to reduce the “background” Excess ??? Direction of Galactic Disc Number of events Sidereal hours ROG Coll.: CQG 19, 5449 (2002) L.S.Finn: CQG 20, L37 (2003) P.Astone, G.D’Agostini, S.D’Antonio: CQG Proc. Of GWDAW 2002, gr-qc/0304096 E. Coccia ROG Coll.:CQG Proc. Of GWDAW 2002 ROG Coll.: gr-qc/0304004 New data needed Amaldi-6 - Barish
EXPLORER NAUTILUS Science Run 03 - crewless operation - data validated by cosmic ray effect - new upper limit with bars, no significant coincidence excess nor sidereal effect. ROG S 01 suggestion ROG S 03 Amaldi-6 - Barish
dashed region excluded with probability > 90% My best guess on the achievable upper limit improvement by IGEC-2 rate [year –1] IGEC-1 upper limit 1 month search threshold WARNING: incomplete data set ! 1 year IGEC-2Expected Performance Triple coincidences: 106 time shifts, no accidentals, 9.3 days false alarm rate < 10-4 / yr for H>1.4 10-21/Hz Double coincidences: lower false alarm rates than for IGEC-1 Amaldi-6 - Barish
Interferometer Detectors LIGO Louisiana 4000m TAMA Japan 300m Virgo Italy 3000m GEO Germany 600m AIGO Australia future LIGO Washington 2000m & 4000m Amaldi-6 - Barish
TAMA Amaldi-6 - Barish Kanda
TAMA Amaldi-6 - Barish Kanda
S4 Sensitivity Amaldi-6 - Barish
Noise Progression of the Louisiana Interferometer Amaldi-6 - Barish
Results for Neutron Star Binaries • Event Candidates • 142 event candidates found in the data • Loudest candidates eliminated in follow up investigation… • Other candidates consistent with background of analysis pipeline • Upper limit set on the rate of BNS coalescences R90 = 47 / year / MWEG Amaldi-6 - Barish
Results for Primordial Black Hole Binaries • Same analysis pipeline • Event rate consistent with background of analysis pipeline • Upper limit set on the rate of PBHB coalescences R90 = 63 / year / MWEG Amaldi-6 - Barish
Stochastic BackgroundPredictions and Experimental Limits Initial LIGO, 1 yr data ExpectedΩ0h1002 < 2x10-6 (H1-L1) LIGO S1, 2 wk data Ω0h1002 < 23 PRD 69(2004)122004 (H2-L1) Advanced LIGO, 1 yr data ExpectedΩ0h1002 < 7x10-10 (H1-L1) Laser Interferometer Space Antenna - LISA LIGO S3, 2 month data Ω0h1002 < 4.4x10-4 (H1-L1) presented here Nucleosynthesis Pulsar LIGO band CMB 0 -2 -4 (W0h1002) Cosmic strings -6 -8 Log Pre-big bang model -10 EW or SUSY Phase transition Inflation -12 Cyclic model Slow-roll -14 -16 -14 -12 -10 -8 -6 -4 -2 0 2 4 6 8 -18 10 Log ( f [Hz]) f ~ 1/Plank scale – red shifted from the Plank era to the present time f ~ H0 - one oscillation in the lifetime of the universe Amaldi-6 - Barish
Conclusions • Sensitivity toward gravitational wave detection is improving on many fronts and this will continue well into the future • New upper limits are being set for the major sources -- binary inspirals, periodic sources, burst sources and stochastic background. • Data exchange and joint data analysis between detector groups is improving our ability to make detections • Many exciting future projects and upgrades are planned or getting underway. • Hopefully, detections will be made soon !! Maybe by Amaldi-7?? Amaldi-6 - Barish
THANKSAmaldi-6 Organizers!!! See at Amaldi-7 Sydney Amaldi-6 - Barish