![Page 1: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/1.jpg)
A proposal for additional Low Frequency
Gravitational WaveInterferometric Detectors
at LIGO
Riccardo DeSalvo
California Institute of TechnologyGlobular Cluster 17th October 2003
LIGO-xxx
![Page 2: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/2.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 2
Status of observationsnow and here!!
• TAMA has been running for >3 years– Steadily improving sensitivity >100 Hz– < factor of 10 from nominal sensitivity
• LIGO has been acquiring data for > 1 year (with GEO)– Steadily improving sensitivity ~100 Hz– < factor of 10 from nominal sensitivity
• Virgo commissioning– Taking data in ~< 1 year– > 20 Hz
• AdLIGO starting up– Foreseen for > 2007– > 40 HzLow Frequency Threshold defined as mirror thermal noise corner!
![Page 3: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/3.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 3
Why LF-GWIDs?• Adv-LIGO will cover the detection of pulsars, NS-
NS and low-mass BH inspirals, the coalescence phase, and other GW physics with its best sensitivity around100 Hz
• Can ground based GWIDs monitor even lower frequencies
• Is this useful to study globular clusters?
![Page 4: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/4.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 4
What is necessary for a LF-GWID?
• GW Interferometers can be optimized for LF with the following changes
– Reduce beam power and different finesse (rad. Pressure)
– Use longer suspensions (susp. TN)
– Use Supersized, double weight, mirrors (coating TN, rad. Pr)
– Use Fused Silica (instead of Sapphire) mirrors (bulk TN)–
• LF-tuning would divert AdLIGO from its original mission!
• Need operation of separate Low and High Frequency complementary interferometers
![Page 5: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/5.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 5
AdL LF-GWID complementarity
NewtonianNoise limit
![Page 6: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/6.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 6
AdL LF-GWID complementarity
End inspiral frequencyFirst BH Kerr resonance
Merger phase follow-up in the frequency mass area above the yellow line
BH ring down in the frequency mass area above the purple line
Triggered searchesLF triggerHF strongly relativisticsignal study
Template Signal integration
![Page 7: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/7.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 7
AdL and LF-GWID
Blue:Low seismicDay
Purple:High seismicDay
Green:Ad-LIGO
3.6 Gpc@37+37sm
Seismic variability
1.15 Gpc@16+16 sm
![Page 8: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/8.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 8
Can we accommodate a LF interferometer next to Adv-LIGO?
• There seems to be space in the LIGO beam pipe just above and forwards of the Adv-LIGO mirrors
• Advanced LIGO nominal beam positions
adv.-LIGO 340 mm diameter
adv-LIGO 340 mm diameter
proposed 430 mm diameter mirror
![Page 9: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/9.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 9
And there appears to be space in the halls
Virgo-like towersTAMA-like towers
![Page 10: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/10.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 10
Conclusions
• IMBH are important and compelling potential GW sources for a LF interferometer
• Optimized LF sensitivity would allow: – Increase quite significantly the explored volume in
the Universe for heavier mass objects(3.6 Gpc, real cosmology reach).
– Study of the genesis of the large galactic BH (believed to be central to the dynamics of galaxies)
– Mapping the globular clusters in our neighborhood – Enhancement of the performance of both Virgo and LIGO
• They would be “triggered” by the LF detection and follow up studying final inspiral and merge signals
• Advanced LIGOs are freer to be narrow banded• Splitting up the frequency range between two different interferometers
eases lots of design constraints and allows better performance from both
![Page 11: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/11.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 11
LF-GWID proposal pointers
Should all be in LIGO DCC, if not availableLF-GWID Amaldi proceedings (LIGO- P030047-00-D): www.ligo.caltech.edu/~desalvo/manuscript-Amaldi2003.docLF-GWID Elba proceedings (LIGO-P030040-00-D):www.ligo.caltech.edu/~desalvo/DESALVO_ELBA_manuscript.doc
LF-GWID Amaldi power point presentation (LIGO-G030332-00-R ):www.ligo.caltech.edu/~desalvo/desalvo_amaldi.pptLF-GWID Elba power point presentation (LIGO-G030292-00-R):www.ligo.caltech.edu/~desalvo/desalvo-elba.ppt
![Page 12: A proposal for additional Low Frequency Gravitational Wave Interferometric Detectors at LIGO Riccardo DeSalvo California Institute of Technology Globular](https://reader031.vdocuments.net/reader031/viewer/2022013012/5697bf821a28abf838c8615b/html5/thumbnails/12.jpg)
Globular Cluster MeetingState College, 17-21 October 2003
LIGO-xxx-00-R 12
Aspen GWDAW workshop winter 2004
• The LIGO S. C. equivalent of this informal meeting is the Aspen meeting.
• February 15 to 21st 2004• Please consider participating. • Input on what is relevant and important to
make good astronomy is very important.• You can help !!