Status of Virgo

1
Status of Virgo
11th Gravitational Wave Data Analysis Workshop
Potsdam, December 18th 2006

• Gabriele Vajente
• INFN Pisa and Scuola Normale Superiore di Pisa
• On behalf of the Virgo Collaboration

2
Virgo collaboration

• New groups joined the collaboration

ESPCI ParisLAPP LAL OrsayLMA LyonOCA
INFN Perugia INFN Firenze INFN NapoliINFN
PisaINFN Roma 1
NIKHEF
INFN Roma 2
3
Restart after shutdown

• Last winter shutdown for hardware upgrades
• Injection bench replacement to run with higher
  input power (10 W enter the ITF)
• Power Recycling mirror replacement with new
  monolithic mirror, higher reflectivity (95 )

4
Thermal issues

• Higher power produces thermal effects

BS Pick-off power Lower sideband Higher sideband

• Lock acquisition long (20 min)
• Thermal transient is a critical period
• Wait for 10 min after reaching dark fringe
  condition
• Needed a reduction of input power to 5.5 W
  (entering the ITF)
• Need for a thermal compensation system, work
  starting

5
Week-end Science Run

• Periodic short data taking started in September
  2006
• start moving towards a science run operation
• take snapshots of the commissioning progress
• take clean data in controlled conditions
• light organization
• priority always on commissioning
• WSR1 September 08th - 11th
• WSR2 September 22th - 25th
• WSR3 October 06th - 09th
• WSR4 October 13th - 16th
• WSR5 November 10th - 13th
• WSR6 December 01th - 04th
• WSR7 January 12th - 15th

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Sensitivity in WSRs
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Comparison of sensitivity
8
Duty cycle and horizon in WSRs
WSR1 Duty cycle 87.7 Longest lock 15 h
WSR2 Duty cycle 68.7 Longest lock 27 h
Horizon for NS NS (averaged) MPc
WSR5 Duty cycle 64.2 Longest lock 10 h
WSR6 Duty cycle 80.5 Longest lock 18 h
9
Dependence on weather conditions

• The horizon is affected by microseismic
  conditions
• Sea activity
• Wind
• Suspension control improvements on-going

RMS 220 mHz 1 Hz
Seismic activity a.u.
RMS 30 mHz 100 mHz
Seismic activity a.u.
Horizon NS-NS optimal MPc
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Noise budget

• Below 50 Hz control noise (longitudinal and
  angular)
• Above 1kHz frequency noise
• and shot noise
• Intermediate region

WSR5
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Acoustic noise / diffused light

• The main suspect is acoustic and seismic noise
  from benches in air
• Through diffused and scattered light effects
• Investigations on-going

Projection of acoustic noise introduced by the
detection bench, measured with acoustic noise
injections
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Brief overview of Data Analysis at Virgo

• Virgo search groups
• Bursts
• Binary inspirals
• Periodic signals
• Stochastic background
• Noise studies
• Virgo-Bars network
• Virgo-LIGO collaboration

13
Brief overview of Data Analysis at Virgo

• Analysis of data quality (talk by E.Cuoco)
• Studies on veto procedures and efficiency (poster
  by M. Del Prete)
• Search fro bursts from GRB 050915a (poster by A.
  Corsi)

• Virgo search groups
• Bursts
• Binary inspirals
• Periodic signals
• Stochastic background
• Noise studies
• Virgo-Bars network
• Virgo-LIGO collaboration

14
Brief overview of Data Analysis at Virgo

• Virgo search groups
• Bursts
• Binary inspirals
• Periodic signals
• Stochastic background
• Noise studies
• Virgo-Bars network
• Virgo-LIGO collaboration

• On-line analysis perfomed using Merlino and MBTA
  algorithms(talk by L. B. Bosi)
• Study on coherent analysis with a network of
  ITF(poster by S. Birindelli)
• Improvements in the timing accuracy(poster by D.
  Grosjean)

15
Brief overview of Data Analysis at Virgo

• Virgo search groups
• Bursts
• Binary inspirals
• Periodic signals
• Stochastic background
• Noise studies
• Virgo-Bars network
• Virgo-LIGO collaboration

• Coincidence analysis between C6 and C7 run (talk
  by C.Palomba)

16
Brief overview of Data Analysis at Virgo

• Virgo search groups
• Bursts
• Binary inspirals
• Periodic signals
• Stochastic background
• Noise studies
• Virgo-Bars network
• Virgo-LIGO collaboration

• Analysis of prospect of detection in a network
  search Virgo/LSC(talk by G.Cella)

17
Brief overview of Data Analysis at Virgo

• Virgo search groups
• Bursts
• Binary inspirals
• Periodic signals
• Stochastic background
• Noise studies
• Virgo-Bars network
• Virgo-LIGO collaboration

• Search and removal of lines(poster by I. Fiori
  et al.)

18
Brief overview of Data Analysis at Virgo

• Virgo search groups
• Bursts
• Binary inspirals
• Periodic signals
• Stochastic background
• Noise studies
• Virgo-Bars network
• Virgo-LIGO collaboration

• Analyzed 24 hours of data in coincidence during
  Virgo C7 run
• ILIAS-WG2 methodological paper under
  preparation(Talk by L. Baggio)

19
Brief overview of Data Analysis at Virgo

• Virgo search groups
• Bursts
• Binary inspirals
• Periodic signals
• Stochastic background
• Noise studies
• Virgo-Bars network
• Virgo-LIGO collaboration

• Comparison of calibration and pipelines
• Methodological work on simulated data
• Exchanges of short data segments for developing
  and testing networkanalysis methods.

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Prospects for the future
Virgo commissioning
TIME
Virgo WSRs
Virgo Scientific Run (in coincidence with S5)
2007
Virgo commissioning
Virgo upgrade
2008
Virgo commissioning
Virgo Scientific Run
2009
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Virgo

• 50 W laser, F150 cavities
• Low loss suprasil end mirrors
• Monolitic suspensions

Thermal noise decreased
Shot noise decreased
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Summary

• WSR program started and continuing
• with good duty cycle
• improving sensitivity (high frequency almost at
  measured shot noise, comparable with LIGO)
• Commissioning continues
• big efforts in the 50 - 500 Hz region
• Goal to have a Science Run in coincidence with
  LSC S5
• Plans for Virgo upgrade