Francesco Fidecaro 21 dicembre 2009 Risultati e prospettive per la rete LV

2 Commissioning: sensitivity progress 25W Virgo+ expected sensitivity 128 effective days of data taking but 0.02 double coincidence event expected

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6 VSR2 sensitivity for CW searches Targeted searches. Vela

7 Compatible with some ‘exotic’ EOS Marginally compatible with standard EOS (Vela spin-down limit in ~80 days) may improve on Crab VSR2 sensitivity Spin-down limit can be beaten for a few pulsars

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29 Stochastic Background (SB) A stochastic background can be a GW field which evolves from an initially random configuration: cosmological background the result of a superposition of many uncorrelated and unresolved sources : astrophysical background) Typical assumptions Gaussian, because sum of many contributions Stationary, because physical time scales much larger than observational ones Isotropic (at least for cosmological backgrounds) If these are true, SB is completely described by its power spectrum

30 Detection method It is stochastic and presumably overwhelmed by noise Need (at least) two detectors to check for statistical correlations Optimal filtering Signals Uncorrelated (?) noises

31 Detection performance Sensitivity improves as T 1/2 Better performances when coherence is high ( ) –detectors near each other compared to –detectors aligned

32 Isotropic search: results Data collected during S5 run (one year integrated data of LIGO interferometers) Point estimate of Y: no evidence of detection integrating over Hz (99% of sensitivity)

33 Isotropic search: results Now we are beyond indirect BBN and CMB bounds We are beginning to probe models

34 Isotropic background: constraint on cosmic strings Parameters: –String constant , G  <10 -6 –Loop size parameter  –Recombination probability p Additional region in the plane is excluded

35 Early universe equation of state “Stiff” energy components in pressure vs density Vertical axis: effective tensor tilt parameter Horizontal axis: equation of state parameter r: scalar/tensor ratio (r=0.1 in the plot)

36 Constraints on pre-big-bang models Free parameters: –  : 1<  <1.5 –f 1 (cut off frequency) Constraint on the  -f 1 plane will be obtained for: –Large values of f 1 –Nearly flat  above f s BBN bound still dominates

37 Joint LIGO/Virgo Search for GRBs Gamma Ray Bursts (GRBs) - brightest EM emitters in the sky –Long duration (> 2 s) bursts, high Z  progenitors are likely core-collapse supernovae –Short duration (< 2 s) bursts, distribution about Z ~ 0.5  progenitors are likely NS/NS, BH/NS, binary merger –Both progenitors are good candidates for correlated GW emissions! 212 GRBs detected during S5/VSR1 –137 in double coincidence (any two of LIGO Hanford, LIGO Livingston, Virgo) No detections, we place lower limits on distance assuming E GW = 0.01 M  c 2

38 M31 The Andromeda Galaxy by Matthew T. Russell Date Taken: 10/22/ /2/2005 Location: Black Forest, CO Equipment: RCOS 16" Ritchey-Chretien Bisque Paramoune ME AstroDon Series I Filters SBIG STL-11000M Refs: GCN: GRB X-ray emission curves (IPN)

9 November GRB070201: Not a Binary Merger in M31! Inspiral (matched filter search: Binary merger in M31 (770 kpc) scenario excluded at >99% level Exclusion of merger at larger distances 90% 75% 50% 25% Inspiral Exclusion Zone 99% Abbott, et al. “Implications for the Origin of GRB from LIGO Observations”, Ap. J., 681:1419–1430 (2008). Burst search: Cannot exclude an SGR in M31 SGR in M31 is the current best explanation for this emission Upper limit: 8x10 50 ergs (4x10 -4 M  c 2 ) (emitted within 100 ms for isotropic emission of energy in GW at M31 distance)

40 The Crab Pulsar: Beating the Spin Down Limit! Remnant from supernova in year 1054 Spin frequency EM = 29.8 Hz  gw = 2 EM = 59.6 Hz observed luminosity of the Crab nebula accounts for < 1/2 spin down power spin down due to: electromagnetic braking particle acceleration GW emission? early S5 result: h < 3.9 x  ~ 4X below the spin down limit (assuming restricted priors) ellipticity upper limit:  < 2.1 x GW energy upper limit < 6% of radiated energy is in GWs Abbott, et al., “Beating the spin-down limit on gravitational wave emission from the Crab pulsar,” Ap. J. Lett. 683, L45-L49, (2008).

41 Monolithic suspensions

42 Monolithic Suspensions Strategic goal significant scientific opportunity by increasing the sensitivity at low frequency unique place to test the monolithic suspension and to explore the level of noise at low frequency before these detectors are built. Main achievements Optimizing the production of suspension fibers and verifying its reliability and reproducibility Measurement of mechanical behaviour of a dummy payload Work on payload assembly and transport trolley Measurements on residual losses limited by the suspension structure.

43 4 GPa Working load Breaking Strength Tests on Fused Silica Wires (280 microns thick) Measurements by Glasgow group (breaking load vs thickness) K. Tokmakov et al., 2009, poster at Amaldi8  m  m bright spots carefully removed by multiple annealing careful cleaning of silica pieces heads clamped without glue IMPROVED TESTING METHOD: more reproducible loading rate Previuos measurements (Virgo Week Nov 2009)

44 Transportation Test Suspension in the test facility

45 Pitch TF (tx) tx Ma/Ma DC=35 urad/V Type f (hz),Q P 0.244,45 Z 0.399,200 P 0.402,200 Z 1.569,200 P 1.581,200 Z 1.703,200 P 3.595,500P 10 tx Mi/Ma Type f (hz),Q P 0.248,45 Z 0.399,200 P 0.402,200 Z 1.703,200 P 1.581,200 P P 10

46 Noise understanding Main contributions Magnetic noise from BS External Inj Bench Resonances in Det bench and dihedron Longitudinal control noise (DSP)

47 LV network performance for NSNS II For this discussion a choice of a False Alarm Rate of 1 event per year is made. Detectors horizon for average orientation H 16 Mpc L 12 Mpc V 9 Mpc current situation H 31 Mpc L 31 Mpc V 47 Mpc design Gain of 30 between May 2009 and design sensitivity 6 months of stop recovered in 6 days

48 Pulsars Spin-down limit can be attained for more than 20 pulsars, almost all below 40 Hz. For five of these (that include Crab and Vela) the corresponding limit on  < (allowed by several “exotic” matter EOS For two  < Crab spindown would be set at less than E GW < E loss

49 Advanced Virgo

G.Losurdo - AdV Project Leader50 AdV BASELINE DESIGN EGO Council - July 2nd, 2009G.Losurdo - AdV Project Leader50 Signal Recycling (SR) Non degenerate rec. cavities High power laser High finesse 3km FP cavities Heavier mirrors Large spot size on TM Larger central links Cryotraps Monolithic suspensions DC readout

G.Losurdo - AdV Project Leader51 SENSITIVITY GOAL STAC - Cascina, Nov 11, 2009G.Losurdo - AdV Project Leader51 Reference sensitivity (125 W in the ITF): SR tuning optimized for BNS Pha_SR = 0.15 BNS = 142 Mpc BBH = 1100 Mpc

ly Enhanced LIGO/Virgo+Virgo/LIGO Credit: R.Powell, B.Berger Adv. Virgo/Adv. LIGO  2 nd generation detectors – BNS inspiral range >10x better than Virgo – Detection rate: ~1000x better – 1 day of Adv data ≈ 3 yrs of data  2 nd generation network. – Timeline: commissioning to start in Advanced detectors

53 Advanced Virgo On December 4 EGO, the Consortium owned by CNRS and INFN, approved the Advanced Virgo Project Significant financial commitments already in 2009 Work in short term: optical scheme, light source, plan on how to provide early new data to the community

54 Perspective

55 Motivation for a Global GW Detector Network LIGO GEO VIRGO TAMA AIGO t1t1 t2t2 t3t3 t5t5 t4t4 t6t6 Time-of-flight to reconstruct source position

56 Motivation for a Global GW Detector Network source location Source location: –Ability to triangulate (or ‘N-angulate’) and more accurately pinpoint source locations in the sky –More detectors provides better source localization  Multi- messenger astronomy Network Sky Coverage: –GW interferometers have a limited antenna pattern; a globally distributed network allows for maximal sky coverage Detection confidence: –Redundancy – signals in multiple detectors Maximum Time Coverage - ‘Always listening’: –Ability to be ‘on the air’ with one or more detectors Source parameter estimation: –More accurate estimates of amplitude and phase –Polarization - array of oriented detectors is sensitive to two polarizations Coherent analysis: –Combining data streams coherently leads to better sensitivity ‘digging deeper into the noise’ –Also, optimal waveform and coordinate reconstruction

57 N Network Sky Coverage GW interferometers have broad sky coverage, but are not omni- directional L/H+L/L 50% L/H+L/L+V 50% L/H+L/L+V+Japan 50% Antenna Pattern (averaged over GW polarization) Bernard Schutz, AEI Figure of Merit:

58 The Future – LCGT (Japan) Based on the long experience of TAMA 300 on Mitaka Campus at NAO Large-scale Cryogenic Gravitational Wave Telescope – 3 km long next generation interferometer –Use of cryogenic cooling of test masses to reduce thermal noise in the ‘sweet spot’ of the detector –Located underground in Kamioka mine to reduce seismic noise coupling to test masses Prototype - Cryogenic Laser Interferometer Observatory (CLIO) currently in operation in Kamioka mine –Testbed for development of seismic isolation and cryogenic technologies

59 The Future – AIGO (Australia) A comparably sensitive detector in Australia will bring increased angular sensitivity and better sky coverage Australian Interferometer Gravitational- wave Observatory conceived as a 5 km interferometer –will follow the AdvLIGO design Possible variation in suspension and seismic isolation system Likely location in Western Australia –Aim for operation in year lag behind AdvLIGO

60 The Future: The Einstein Telescope (Europe)

61 Mission: to facilitate international collaboration and cooperation in the construction, operation and use of the major gravitational wave detection facilities world-wide. –sub-committee of International Union of Pure and Applied Physics (IUPAP)’s Particle and Nuclear Astrophysics and Gravitation International Committee. GWIC has developed a Roadmap –A strategic plan that gives an overview of the gravitational wave field, the potential discoveries and the facilities and resources needed to reach them Includes ground-based, space-based, pulsar timing –Intended audience: GW community, other scientific communities, funding agencies A coherent, science driven plan looking 30 years into the future! A draft of the Roadmap is available at –Executive Summary – 13 pages –Complete Roadmap – 108 pages

62 Perspectives for third generation Sources are waiting –Systems at cosmological distance –High statistics in binary systems (inspiral waveforms, matter distribution) –Increased sensitivity in merge and ringdown phase (GR, EOS) –Increased number of pulsars (EOS, population, ) –Stochastic background (cosmological and astrophysical) –Coincidences with  and X-ray satellites, observatories, …(system dynamics) Gaining another factor 10 in sensitivity Extending frequency down to a few Hz Extending further frequency spectrum spectrum –Pulsar timing –High frequency gravitational waves

63 Sensitivity future evolution

64 Einstein Telescope: time scale