1. Searching for gravitational waves with lasers (LIGO)
Rick Savage
Caltech LIGO Hanford Observatory - Richland, WA

2. Black holes and time warps
Transferred to UCLA in Physics in 1974
Jan 1975
Started working for F. Chen and N. Luhmann as undergraduate lab assistant (with Doug Cook)
Alain Semet, John Turcek, Steve Obenschain, Jim Holt, Mark Herbst, et al.
Plasma diagnostics
N. Luhmann, T. Peebles, H. Fetterman, et al.
Microtorr, macrotorr, UT FRC, FIR lasers, CO2 lasers
1986 – 1992 Laser / Plasma interactions
Graduate school in EE at UCLA – Chan Joshi
Masters thesis – Degenerate four-wave mixing in heated CO2 gas
PhD thesis – Frequency upshifting of electromagnetic radiation via an underdense relativistic ionization front
1992 – present
LIGO project – Caltech until 1997 then LIGO Hanford Observatory in Richland, WA
LIGO-G
UCLA Symposium Nov. 2009

3. http://www.einsteinsmessengers.org/ LIGO-G0901004
UCLA Symposium Nov. 2009

4. LIGO: Laser Interferometer Gravitational-wave Observatory
Hanford, WA
MIT
3002 km
(L/c = 10 ms)
Caltech
Managed and operated by Caltech & MIT with funding from NSF
Goal: Direct observation of gravitational waves
Open an new observational window on the Universe
Livingston, LA

5. LIGO Scientific Collaboration
Australian Consortium for Interferometric Gravitational Astronomy
The Univ. of Adelaide
Andrews University
The Australian National Univ.
The University of Birmingham
California Inst. of Technology
Cardiff University
Carleton College
Charles Sturt Univ.
Columbia University
CSU Fullerton
Embry Riddle Aeronautical Univ.
Eötvös Loránd University
University of Florida
German/British Collaboration for the Detection of Gravitational Waves
University of Glasgow
Goddard Space Flight Center
Leibniz Universität Hannover
Hobart & William Smith Colleges
Inst. of Applied Physics of the Russian Academy of Sciences
Polish Academy of Sciences
India Inter-University Centre for Astronomy and Astrophysics
Louisiana State University
Louisiana Tech University
Loyola University New Orleans
University of Maryland
Max Planck Institute for Gravitational Physics
University of Michigan
University of Minnesota
The University of Mississippi
Massachusetts Inst. of Technology
Monash University
Montana State University
Moscow State University
National Astronomical Observatory of Japan
Northwestern University
University of Oregon
Pennsylvania State University
Rochester Inst. of Technology
Rutherford Appleton Lab
University of Rochester
San Jose State University
Univ. of Sannio at Benevento, and Univ. of Salerno
University of Sheffield
University of Southampton
Southeastern Louisiana Univ.
Southern Univ. and A&M College
Stanford University
University of Strathclyde
Syracuse University
Univ. of Texas at Austin
Univ. of Texas at Brownsville
Trinity University
Tsinghua University
Universitat de les Illes Balears
Univ. of Massachusetts Amherst
University of Western Australia
Univ. of Wisconsin-Milwaukee
Washington State University
University of Washington
LIGO Scientific Collaboration
LIGO-G
UCLA Symposium Nov. 2009

6. General relativity – gravitational waves
“Matter tells spacetime how to curve. Spacetime tell matter how to move.” J. A Wheeler
Albert Einstein 1916
GW: oscillating quadrupolar strain in spacetime
Laser Interferometer
LIGO-G
UCLA Symposium Nov. 2009

7. Detection of graviational waves
Michelson interferometer
- differential length change sensor
LIGO-G
UCLA Symposium Nov. 2009

8. Do they exist? Indirect evidence
(Weisberg, Taylor)
Pulsar System PSR
(R.A. Hulse, J.H. Taylor Jr, 1975)
A 17/sec pulsar (neutron star in rapid rotation, emanating periodic pulses of electromagnetic radiation) orbits around a neutron star with period = 8 hours
Only 7kpc away
General Relativity prediction: the orbital radius diminishes 3mm/orbit; a collision is expected in 300 million years
The rotation period diminished 14 sec in ; energy loss
Optimum agreement with the predictions of general relativity: the energy is carried away by gravitational waves!
The “inspiral” will accelerate at the end, when the neutron stars coalesce
Gravitational wave emission will be strongest near the end
Orbit will continue to decay over the next ~300 million years, until coalescence
Gravitational wave emission will be strongest near the end
LIGO-G
UCLA Symposium Nov. 2009

9. Capturing the waveform
Sketch:
Kip Thorne
LIGO-G
UCLA Symposium Nov. 2009

10. Sources Coalescing Binary Systems
Credit: AEI, CCT, LSU
Coalescing Binary Systems
Neutron stars, low mass black holes, and NS/BS systems
Credit: Chandra X-ray Observatory
‘Bursts’
galactic asymmetric core collapse supernovae
cosmic strings
???
Casey Reed, Penn State
NASA/WMAP Science Team
Cosmic GW background
stochastic, incoherent background
Continuous Sources
Spinning neutron stars
probe crustal deformations
LIGO-G
UCLA Symposium Nov. 2009

11. Ligo detectors Power Recycled Michelson Interferometer
Laser
4 km-long Fabry-Perot arm cavity
recycling
mirror
test masses
beam splitter
Power Recycled
Michelson
Interferometer
with Fabry-Perot
Arm Cavities
signal
LIGO-G
UCLA Symposium Nov. 2009

12. iLigo hardware
LIGO-G
UCLA Symposium Nov. 2009

13. S5 Science Run Nov 2005 – Oct 2007 LIGO-G0901004
UCLA Symposium Nov. 2009

14. Scientific results of S5 run
No detections (so far) - data still being analyzed
Astrophysical results – upper limits “If LIGO didn’t detect it, then it can’t be bigger than …”
CRAB pulsar – “no more than 4 percent of the energy loss of the pulsar is caused by the emission of gravitational waves.” (ApJL 683, L45)
Gamma ray burst GRB – LIGO “results give an independent way to reject hypothesis of a compact binary progenitor in M31” (ApJ 2008, 681, 1419)
Upper limit on the stochastic gravitational wave background ( v460/n7258/pdf/nature08278.pdf)
Credits for X-ray Image: NASA/CXC/ASU/J. Hester et al.
Credits for Optical Image: NASA/HST/ASU/J. Hester et al.
LIGO-G
UCLA Symposium Nov. 2009

15. LIGO-G
UCLA Symposium Nov. 2009

16. LIGO-G0901004 UCLA Symposium F2C@80 Nov. 2009 108 ly Enhanced LIGO
LIGO today
Credit: R.Powell, B.Berger
Adv. LIGO
LIGO-G
UCLA Symposium Nov. 2009

17. LIGO-G
UCLA Symposium Nov. 2009

18. 10 W to 200 W laser source LIGO-G0901004
UCLA Symposium Nov. 2009

19. Single to quadruple pendulum
LIGO-G
UCLA Symposium Nov. 2009

20. Passive to active vibration isolation
LIGO-G
UCLA Symposium Nov. 2009

21. Time warps UCLA Laser/Plasma interactions
LIGO-G
UCLA Symposium Nov. 2009

22. LIGO-G
UCLA Symposium Nov. 2009

23. LIGO Scientific Collaboration
LIGO-G
UCLA Symposium Nov. 2009

24. Laser Interferometer Gravitational-wave Observatory
Started as a collaboration between Caltech and MIT
Goal: direct observation of gravitational waves
Open a new observational window on the Universe 3 k m ( 1 s )
CALTECH
Pasadena
MIT
Boston
HANFORD
Washington
LIVINGSTON
Louisiana
LIGO-G
UCLA Symposium Nov. 2009

25. LIGO Hanford Observatory
South-central Washington
Where Columbia, Yakima, and Snake rivers converge
LIGO-G
UCLA Symposium Nov. 2009

26. Frank’s thinking ….. inflatable kiyak ? ….
LIGO
Doug Cook Columbia River
credit: Google Maps
LIGO-G
UCLA Symposium Nov. 2009

27. LIGO-G
UCLA Symposium Nov. 2009

28. LIGO-G
UCLA Symposium Nov. 2009

29. closer look – more lasers and optics
LIGO-G
UCLA Symposium Nov. 2009