1. LIGO-G020412-00-M LIGO Update ------------ “ The Search for Gravitational Waves” Barry Barish Caltech Trustees 10-Sept-02

2. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees2 Laser Interferometer Gravitational-wave Observatory Goals »First direct detection of gravitational waves »Open new window on the universe – “gravitational wave astronomy” NSF funded construction in 1994 for $296M »Caltech has fiduciary responsibility »Joint Caltech/MIT technical and scientific team »Construction completed in both Louisiana and Washington in 2000 Commissioning, Operations and Scientific Programs »First Interferometer “locked” – (Oct 2000) »First coincidence running of both sites – (Dec 2001) »First scientific data run “upper limits” – (Sept 2002) »Search for gravitational waves – (2003 through 2006) We propose to install “Advanced LIGO” in 2007 »Cost ~ $125M total -- international collaboration

3. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees3 LIGO Scientific Collaboration Member Institutions University of Adelaide ACIGA Australian National University ACIGA California State Dominquez Hills Caltech LIGO Caltech Experimental Gravitation CEGG Caltech Theory CART University of Cardiff GEO Carleton College Cornell University University of Florida @ Gainesville Glasgow University GEO University of Hannover GEO Harvard-Smithsonian India-IUCAA IAP Nizhny Novgorod Iowa State University Joint Institute of Laboratory Astrophysics LIGO Livingston LIGOLA LIGO Hanford LIGOWA Louisiana State University Louisiana Tech University MIT LIGO Max Planck (Garching) GEO Max Planck (Potsdam) GEO University of Michigan Moscow State University NAOJ - TAMA University of Oregon Pennsylvania State University Exp Pennsylvania State University Theory Southern University Stanford University University of Texas@Brownsville University of Western Australia ACIGA University of Wisconsin@Milwaukee LSC Membership 35 institutions > 350 collaborators International India, Russia, Germany, U.K, Japan and Australia. The international partners are involved in all aspects of the LIGO research program.

4. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees4 Livingston Optical Telescope broad outreach/education program Telescope facts: 16 inch Richey Chretien telescope built by Optical Guidance Systems Telescope provided by state funds via LSU. LIGO provides site and internet connection and incorporates telescope use into outreach program. Internet accessible to facilitate classroom use Proposed telescope location on fire access road gives clear view to south Draft building concept utilizes surplus beam tube enclosures on raised footings with roll-off roof

5. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees5 Budget LIGO Operations (2002 thru 2006) l Operations of LIGO funded beginning in 2002 for 5 years at a total funding of $160M l We function as one distributed laboratory (LIGO Laboratory) »Caltech (85 staff); MIT (25staff); Hanford (25 staff); Livingston (25 staff) l Advanced LIGO construction (not included) to be proposed next year FY 2002 ($M) FY 2003 ($M) FY 2004 ($M) FY 2005 ($M) FY 2006 ($M) Operations$24$29$30 Advanced R&D $4 $3 + $5M

6. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees6 LIGO at Caltech Faculty »Barish, Drever, Libbrecht, Prince and Weinstein (Exp) & Thorne(Th) Scientists/Postdocs/Students »PhD theses; talented junior and senior scientists LIGO Management »Directorate, Administration LIGO Technical »Engineering center – precision engineering; controls; electronics »40 meter prototype; Optical laboratories, etc LIGO Data Analysis and Computing »Simulations; Analysis infrastructure, Networking, Data Archive »Scientific data analysis efforts Source Simulations – Numerical Relativity

7. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees7 Einstein’s Theory of Gravitation gravitational waves A necessary consequence of Special Relativity with its finite speed for information transfer Time dependent gravitational fields come from the acceleration of masses and propagate away from their sources as a space-time warpage at the speed of light Newton’s Theory “instantaneous action at a distance” Einstein’s Theory information carried by gravitational radiation at the speed of light

8. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees8 Direct Detection astrophysical sources Detectors in space LISA Gravitational Wave Astrophysical Source Terrestrial detectors LIGO, TAMA, Virgo,AIGO

9. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees9 International network (LIGO, Virgo, GEO, TAMA, AIGO) of suspended mass Michelson-type interferometers on earth’s surface detect distant astrophysical sources Interferometers terrestrial suspended test masses free masses

10. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees10 Suspended Mass Interferometer the concept An interferometric gravitational wave detector »A laser is used to measure the relative lengths of two orthogonal cavities (or arms) As a wave passes, the arm lengths change in different ways…. …causing the interference pattern to change at the photodiode Arms in LIGO are 4km » Current technology then allows one to measure h =  L/L ~ 10 -21 which turns out to be an interesting target

11. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees11 How Small is 10 -18 Meter? Wavelength of light, about 1 micron One meter, about 40 inches Human hair, about 100 microns LIGO sensitivity, 10 -18 meter Nuclear diameter, 10 -15 meter Atomic diameter, 10 -10 meter

12. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees12 What Limits Sensitivity of Interferometers? Seismic noise & vibration limit at low frequencies Atomic vibrations (Thermal Noise) inside components limit at mid frequencies Quantum nature of light (Shot Noise) limits at high frequencies Myriad details of the lasers, electronics, etc., can make problems above these levels

13. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees13 Noise Floor 40 m prototype displacement sensitivity in 40 m prototype. comparison to predicted contributions from various noise sources sensitivity demonstration

14. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees14 LIGO long baseline interferometers (4 km) Hanford Observatory Livingston Observatory Laser Interferometer Gravitational-wave Observatory (LIGO)

15. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees15 LIGO Livingston Observatory

16. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees16 LIGO Hanford Observatory

17. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees17 LIGO beam tube LIGO beam tube under construction in January 1998 65 ft spiral welded sections girth welded in portable clean room in the field 1.2 m diameter - 3mm stainless 50 km of weld NO LEAKS !!

18. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees18 LIGO vacuum equipment

19. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees19 Core Optics fused silica LIGO requirements l Surface uniformity < 1 nm rms l Scatter < 50 ppm l Absorption < 2 ppm l ROC matched < 3% l Internal mode Q’s > 2 x 10 6 LIGO measurements central 80 mm of 4ITM06 (Hanford 4K) rms = 0.16 nm optic far exceeds specification. Surface figure = / 6000

20. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees20 Core Optics installation and alignment

21. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees21 Interferometer locking Laser end test mass Light bounces back and forth along arms about 150 times input test mass Light is “recycled” about 50 times signal Requires test masses to be held in position to 10 -10 -10 -13 meter: “Locking the interferometer”

22. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees22 Lock Acquisition

23. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees23 LIGO watching the interferometer lock signal Laser X Arm Y Arm Composite Video

24. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees24 LIGO watching the interferometer lock signal X Arm Y Arm Laser X arm Anti-symmetric port Y arm Reflected light 2 min

25. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees25 An earthquake occurred, starting at UTC 17:38. The plot shows the band limited rms output in counts over the 0.1- 0.3Hz band for four seismometer channels. We turned off lock acquisition and are waiting for the ground motion to calm down. From electronic logbook 2-Jan-02 Engineering Run detecting earthquakes

26. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees26 17:03:03 01/02/2002 ========================================================================= Seismo-Watch Earthquake Alert Bulletin No. 02-64441 ========================================================================= Preliminary data indicates a significant earthquake has occurred: Regional Location: VANUATU ISLANDS Magnitude: 7.3M Greenwich Mean Date: 2002/01/02 Greenwich Mean Time: 17:22:50 Latitude: 17.78S Longitude: 167.83E Focal depth: 33.0km Analysis Quality: A Source: National Earthquake Information Center (USGS-NEIC) Seismo-Watch, Your Source for Earthquake News and Information. Visit http://www.seismo-watch.com ========================================================================= All data are preliminary and subject to change. Analysis Quality: A (good), B (fair), C (poor), D (bad) Magnitude: Ml (local or Richter magnitude), Lg (mblg), Md (duration), =========================================================================

27. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees27 Detecting the Earth Tides Sun and Moon

28. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees28

29. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees29 LIGO Goals and Priorities Interferometer performance »Integrate commissioning and data taking consistent with obtaining one year of integrated data at h = 10 -21 by end of 2006 Physics results from LIGO I »Initial upper limit results by early 2003 »First search results in 2004 »Reach LIGO I goals by 2007 Advanced LIGO »Prepare advanced LIGO proposal this fall »International collaboration and broad LSC participation »Advanced LIGO installation beginning by 2007

30. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees30 Preliminary

31. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees31

32. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees32 Astrophysical Sources the search for gravitational waves Compact binary inspiral: “chirps” »NS-NS waveforms are well described »BH-BH need better waveforms »search technique: matched templates Supernovae / GRBs: “bursts” »burst signals in coincidence with signals in electromagnetic radiation »prompt alarm (~ one hour) with neutrino detectors Pulsars in our galaxy: “periodic” »search for observed neutron stars (frequency, doppler shift) »all sky search (computing challenge) »r-modes Cosmological Signals“stochastic background”

33. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees33 “Stochastic Background” cosmological signals ‘Murmurs’ from the Big Bang signals from the early universe Cosmic microwave background

34. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees34 Stochastic Background coherence plot LHO 2K & LLO 4K

35. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees35 Stochastic Background projected sensitivities

36. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees36 Advanced LIGO Active Seismic Multiple Suspension Saphire Optics Higher Power Laser

37. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees37 Advanced LIGO Enhanced Systems improved laser suspension seismic isolation test mass material narrow band optics Improvement factor ~ 10 4

38. LIGO-G020412-00-M 10-Sept-02Caltech Board of Trustees38 Gravitational-wave Astronomy frequency range l EM waves are studied over ~20 orders of magnitude »(ULF radio  HE  -rays) l Gravitational Waves over ~10 orders of magnitude » (terrestrial + space) Audio band LIGO I (2003-06) Adv LIGO (2008 -) LISA 2011-