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Status and perspectives of the virgo detector. Gianluca Gemme INFN Genova. The Virgo collaboration . INFN Sez . Firenze/ Un.Urbino Sez . Genoa Sez . Napoli/Un. Federico II & Salerno Sez.Perugia /Un . Perugia & C amerino Sez . Pisa/Un. Pisa Sez . Roma/Un. Sapienza
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Status and perspectives of the virgo detector Gianluca Gemme INFN Genova
The Virgo collaboration • INFN • Sez. Firenze/Un.Urbino • Sez. Genoa • Sez. Napoli/Un. Federico II & Salerno • Sez.Perugia/Un. Perugia & Camerino • Sez. Pisa/Un. Pisa • Sez. Roma/Un. Sapienza • Sez.Roma 2/Un. Tor Vergata • Sez. Padova/ Un. Trento • CNRS • APC – Paris • LMA – Lyon • LAL – Orsay • LAPP – Annecy • LKB - Paris • OCA – Nice • Nikhef–Amsterdam • POLGRAV – Warsaw (Polish Ac. Sci.) • RMKI (Hungarian Ac. Sci. Budapest) • EGO phys. group XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
The Virgo detector 3 km long Fabry-Perot cavities: to lengthen the optical path to 100 km Power recycling mirror: to increase the light power to 1 kW XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
The Virgo detector 3 km long Fabry-Perot cavities: to lengthen the optical path to 100 km Power recycling mirror: to increase the light power to 1 kW Stable powerful laser Large and high quality mirrors Very good seismic isolation High vacuum XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
GEO600, Hanover, Germany LIGO – Hanford, WA Virgo, Pisa, Italy LIGO – Livingston, LA A worldwide network of detectors Virgo and the LIGO Scientific Collaboration have signed a MoU for full data exchange and joint data analysis and publication policy XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
’05 ’06 ’07 ’08 ’09 ’10 ’11 ’12 ’13 ’14 ’15 ’16 Science runs Now ?? Advanced LIGO → LIGO S4 S5 S6 S7 S8 GEO-HF AstroWatch GEO VSR1 VSR2 VSR3 VSR4 VSR5 Advanced Virgo → Virgo XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
LSC - Virgo sensitivities The last decade has seen the demonstration of GW interferometers technology. Design sensitivity reached, high duty cycle, O(90%) NO DETECTION, YET Same HF sensitivity LIGO at design sensitivity since S5, already in 2007 Virgo reached design during VSR2, in 2009 By design, LIGO better in the intermediate range, Virgo better at low frequencies XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
GW transient signal searches • Search for Gravitational Waves from C.B. in LIGO and Virgo (S5 and VSR1) Coalescing binaries: Phys. Rev. D 79, 122001 (2009), arXiv:0901.0302 Bursts: arXiv: 0905.0020, arXiv:0904.4910 (submitted. Phys. Rev.) XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
GW transient signal searches • Search for GW associated to GRB in S5 and VSR1 ( Ap. J., 715:1453–1461, 2010) no statistically significant gravitational-wave candidates within a [ – 5, + 1) s window around the trigger time of any GRB no evidence for an excess of weak gravitational-wave signals in our sample of GRBs neutron star-black hole progenitors excluded up to a median 90% confidence exclusion distance of 6.7 Mpc XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
VSR2 sensitivity for CW searches Vela XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
VSR2 sensitivity for CW searches Vela spin-down limit in ~80 day XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
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 • 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). XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
GW continuous signal search: VSR2 Vela search • Result, based just on VIRGO data, will beat the spin-down limit of 3.3 x 10-24 (paper in preparation for Apj): • Analysis based on three pipelines (--> almost the same sensitivity) • Rome – Matched filter in Fourier space– New method- Extremely effective from computational point of view • Warsaw – Uses original F-statistic and new G-statistic for imposing constraint from known orientation of pulsar • Glasgow – Uses familiar coarse/fine heterodyne stages and Bayesian pdf determination. Standard approach of the LIGO community XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
Electromagnetic Follow-Ups to GW Triggers Swift TAROT QUEST • Analyze GW data promptly to identify event candidates and reconstruct their apparent sky positions; alert telescopes • Try to capture an EM transientthat would otherwise havebeen missed ! • First attempts underway XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
Arecibo Green Bank LOFAR Additional Messengers ANTARES IceCube • High-energy neutrinos • Models for emission from GRBs – even “failed GRBs” • Joint searches planned with neutrino telescopes • Radio transients XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
Virgo+ • Increase input power • Laser amplifier 50 W • New input mode-cleaner mirror • Thermal compensation system • Improve thermal noise • Monolithic suspensions • Dedicated shutdown(s) for installation during VSR2 • Change mirrors for higher cavity finesse at the same time • Cut down on environmental noises • New control electronics XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
Virgo+ • Increase input power • Laser amplifier 50 W • New input mode-cleaner mirror • Thermal compensation system L. Sperandio, Sviluppo del sistema di compensazion e termica per AdV • Improve thermal noise • Monolithic suspensions • Dedicated shutdown(s) for installation during VSR2 • Change mirrors for higher cavity finesse at the same time • Cut down on environmental noises • New control electronics XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
VSR3 sensitivity and noise budget XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
VSR3 sensitivity and noise budget No improvements compared to VSR2 up to now!! XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
The majority of diffused light affecting sensitivity is expected from the detection bench Diffused light The prism, the most brilliant object B1S dumper from west XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
VSR3 performance XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
VSR3 performance XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
A refinement of diffused light noise projection suggests: Diffused light Suspended Detection bench/Tower dominates 30 – 50 Hz and contributes significantly up to 150 Hz WE contributes 40 and 100 Hz region. Now almost canceled by last week intervention XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
From VSR2 to VSR3: a main optical change • (*VIRGO configuration before2008, i.e. before the change of the North end mirror because of the viewport accident) • Higher losses , but limited loss asymmetry between the two cavities ( V 70 ppm , V+ 180 ppm) • Higher geometrical asymmetry . Curvature Difference : from V* 40 m , V+ 130 m • beam overlap less efficient (transverse beam dimension 17.5 and 19.5 mm) • less power in the TEM 00 mode • higher shot noise contribution • more diffused light • VIRGO+ is equipped with new mirrors • Suprasill substrate, Ta2O5:Ti coating XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
Ring heaters Courtesy of GEO XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
Ring heaters Ring Heater Body (Aluminum) Supporting plate (Aluminum) PEEK Thermal Insulating Supports XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
LIGO - Virgo eLIGO - Virgo+ AdvLIGO - AdvVirgo Advanced detectors A factor 10 on the sensitivity A factor 1000 on the rate of events 1 year of initial detectors < 1 day of advanced detectors ! XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
LIGO - Virgo eLIGO - Virgo+ AdvLIGO - AdvVirgo Advanced detectors A factor 10 on the sensitivity A factor 1000 on the rate of events 1 year of initial detectors < 1 day of advanced detectors ! Predictions for the Rates of Compact Binary Coalescences Observable by Ground-based Gravitational-wave Detectors C.Q.G.27:173001,2010 XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
LIGO - Virgo eLIGO - Virgo+ AdvLIGO - AdvVirgo Advanced detectors A factor 10 on the sensitivity A factor 1000 on the rate of events 1 year of initial detectors < 1 day of advanced detectors ! Predictions for the Rates of Compact Binary Coalescences Observable by Ground-based Gravitational-wave Detectors C.Q.G.27:173001,2010 XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
AdV baseline design heavier mirrors low dissipation coating larger spot high finesse cavity compensation of thermal lensing fused silica suspension fibers signal recycling high power laser (200 W) DC detection XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
AdV sensitivity XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
AdV sensitivity XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
AdV planning • Baseline design available • Construction ready to go • Test mass substrates received • Corrective coating robot being assembled • Order for the first cryotrap ready to go • Planned shutdown for AdV installation: mid 2011- March 2014 • Commissioning: March 2014 – end of 2014 • Scientific data run: mid 2015 XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
A look further, beyond 2° generation? ET, THE “ULTIMATE” DETECTOR • Underground facility to minimize seismic noise • Mirrors held at cryogenic temperature • 10 km arms, new geometries E.T. -Einstein gravitational-wave Telescope • Design Study Proposal funded by EU within FP7 • Large part of the European GW community involved (EGO, INFN, MPI, CNRS, NIKHEF, Univ. Birmingham, Cardiff, Glasgow) Credit: H.Lück XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
A look further, beyond 2° generation? ET, THE “ULTIMATE” DETECTOR • Underground facility to minimize seismic noise • Mirrors held at cryogenic temperature • 10 km arms, new geometries M. Punturo, The ET project, a 3rd generation gw observatory E.T. -Einstein gravitational-wave Telescope • Design Study Proposal funded by EU within FP7 • Large part of the European GW community involved (EGO, INFN, MPI, CNRS, NIKHEF, Univ. Birmingham, Cardiff, Glasgow) Credit: H.Lück XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010
Conclusions First generation GW detectors demonstrated! LIGO and Virgo upgrading towards 2° generation!! Science results start to flow in, good hope that 2° generation will start GW ASTRONOMY! Closer cooperation with the astrophysical community is a must. Gamma, neutrino, radio, optical, GW information are complementary to understand emission mechanisms and ultimately the physics of the sources. XCVI Congresso Nazionale della Società Italiana di Fisica, Bologna, 23/09/2010