1 / 60

Risultati e prospettive per la rete LV

Risultati e prospettive per la rete LV. Francesco Fidecaro 21 dicembre 2009. Commissioning: sensitivity progress. 25W Virgo+ expected sensitivity. 128 effective days of data taking but 0.02 double coincidence event expected. VSR2 sensitivity for CW searches Targeted searches. Vela.

eli
Download Presentation

Risultati e prospettive per la rete LV

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

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

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

  3. VSR2 sensitivity for CW searches Targeted searches. Vela

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

  5. Luce non classica

  6. Likely rates: 10-4 yr-1 L10-1

  7. 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

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

  9. Detection performance • Sensitivity improves as T1/2 • Better performances when coherence is high ( ) • detectors near each other compared to l • detectors aligned

  10. 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 40-170 Hz (99% of sensitivity)

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

  12. Isotropic background: constraint on cosmic strings • Parameters: • String constant m, Gm<10-6 • Loop size parameter e • Recombination probability p • Additional region in the plane is excluded

  13. 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 EGW= 0.01 Mc2

  14. GRB 070201 Refs: GCN: http://gcn.gsfc.nasa.gov/gcn3/6103.gcn3 X-ray emission curves (IPN) M31The Andromeda Galaxy by Matthew T. Russell Date Taken:10/22/2005 - 11/2/2005Location:Black Forest, COEquipment:RCOS 16" Ritchey-ChretienBisque Paramoune MEAstroDon Series I FiltersSBIG STL-11000M http://gallery.rcopticalsystems.com/gallery/m31.jpg

  15. GRB070201: Not a Binary Merger in M31! Inspiral Exclusion Zone 25% 50% 75% 90% 99% • Burst search: • Cannot exclude an SGR in M31 • SGR in M31 is the current best explanation for this emission • Upper limit: 8x1050 ergs (4x10-4 Mc2) (emitted within 100 ms for isotropic emission of energy in GW at M31 distance) Abbott, et al. “Implications for the Origin of GRB 070201 from LIGO Observations”, Ap. J., 681:1419–1430 (2008). • Inspiral (matched filter search: • Binary merger in M31 (770 kpc) scenario excluded at >99% level • Exclusion of merger at larger distances

  16. The Crab Pulsar: Beating the Spin Down Limit! • Remnant from supernova in year 1054 • Spin frequency nEM = 29.8 Hz •  ngw = 2 nEM = 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 10-25 ~ 4X below • the spin down limit (assuming restricted priors) • ellipticity upper limit: e < 2.1 x 10-4 • 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).

  17. Monolithic suspensions

  18. 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.

  19. Breaking Strength Tests on Fused Silica Wires (280 microns thick) • bright spots carefully removed by multiple annealing • careful cleaning of silica pieces • heads clamped without glue IMPROVED TESTING METHOD: more reproducible loading rate 4 GPa Working load 310 mm 260 mm Previuos measurements (Virgo Week Nov 2009) Measurements by Glasgow group (breaking load vs thickness) K. Tokmakov et al., 2009, poster at Amaldi8

  20. Transportation Test Suspension in the test facility

  21. 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 3.595 400 P 10

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

  23. 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

  24. 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 e < 10-4. (allowed by several “exotic” matter EOS • For two e < 10-5. • Crab spindown would be set at less than EGW < 10-3 Eloss

  25. Advanced Virgo

  26. AdV BASELINE DESIGN Heavier mirrors Larger central links Cryotraps High finesse 3km FP cavities Large spot size on TM Monolithic suspensions Non degenerate rec. cavities High power laser Signal Recycling (SR) DC readout EGO Council - July 2nd, 2009 G.Losurdo - AdV Project Leader G.Losurdo - AdV Project Leader 50

  27. SENSITIVITY GOAL Reference sensitivity (125 W in the ITF): SR tuning optimized for BNS Pha_SR = 0.15 BNS = 142 Mpc BBH = 1100 Mpc STAC - Cascina, Nov 11, 2009 G.Losurdo - AdV Project Leader G.Losurdo - AdV Project Leader 51

  28. Advanced detectors • 2nd generation detectors • BNS inspiral range >10x better than Virgo • Detection rate: ~1000x better • 1 day of Adv data ≈ 3 yrs of data • 2nd generation network. • Timeline: commissioning to start in 2014. Enhanced LIGO/Virgo+ Virgo/LIGO 108 ly Adv. Virgo/Adv. LIGO Credit: R.Powell, B.Berger 52

More Related