LIGO-xxx

1. Gravitational Wave Detection of Astrophysical SourcesBarry C. BarishCaltechNeutrino Telescope Venice24-Feb-05 Crab Pulsar LIGO-xxx

2. Einstein’s Theory of Gravitation • a necessary consequence of Special Relativity with its finite speed for information transfer • gravitational waves come from the acceleration of masses and propagate away from their sources as a space-time warpage at the speed of light gravitational radiation binary inspiral of compact objects Venice Neutrino Telescope

3. Einstein’s Theory of Gravitation gravitational waves • Using Minkowski metric, the information about space-time curvature is contained in the metric as an added term, hmn. In the weak field limit, the equation can be described with linear equations. If the choice of gauge is thetransverse traceless gaugethe formulation becomes a familiar wave equation • The strain hmn takes the form of a plane wave propagating at the speed of light (c). • Since gravity is spin 2, the waves have two components, but rotated by 450 instead of 900 from each other. Venice Neutrino Telescope

4. Detectionof Gravitational Waves Gravitational Wave Astrophysical Source Terrestrial detectors Virgo, LIGO, TAMA, GEO AIGO Detectors in space LISA Venice Neutrino Telescope

5. Gravitational Waves in Space LISA Three spacecraft, each with a Y-shaped payload, form an equilateral triangle with sides 5 million km in length. Venice Neutrino Telescope

6. LISA The diagram shows the sensitivity bands for LISA and LIGO Venice Neutrino Telescope

7. Detecting a passing wave …. Free masses Venice Neutrino Telescope

8. Detecting a passing wave …. Interferometer Venice Neutrino Telescope

9. Interferometer Concept As a wave passes, the arm lengths change in different ways…. • Arms in LIGO are 4km • Measure difference in length to one part in 1021 or 10-18 meters • Laser used to measure relative lengths of two orthogonal arms …causing the interference pattern to change at the photodiode Suspended Masses Venice Neutrino Telescope

10. Simultaneous Detection 3002 km (L/c = 10 ms) Hanford Observatory MIT Caltech Livingston Observatory Venice Neutrino Telescope

11. LIGO Livingston Observatory Venice Neutrino Telescope

12. LIGO Hanford Observatory Venice Neutrino Telescope

13. LIGO Goals and Priorities • Interferometer performance • Integrate commissioning and data taking • Obtain one year of integrated data at h = 10-21 by 2008 • Physics results from LIGO I • Initial upper limit results by early 2003 • First search to begin in 2005 • Reach LIGO I goals by 2008 • Advanced LIGO • Advanced LIGO approved at NSF / NSB (Nov 04) for ($185M) • Included in the Bush Administration’s budget plan released Feb 05 for 2008 start Venice Neutrino Telescope

14. Lock Acquisition Venice Neutrino Telescope

15. What Limits LIGO Sensitivity? • Seismic noise limits low frequencies • Thermal Noise limits middle frequencies • Quantum nature of light (Shot Noise) limits high frequencies • Technical issues - alignment, electronics, acoustics, etc limit us before we reach these design goals Venice Neutrino Telescope

16. Evolution of LIGO Sensitivity Venice Neutrino Telescope

17. Detecting Earthquakes From electronic logbook 2-Jan-02 An earthquake occurred, starting at UTC 17:38. Venice Neutrino Telescope

18. Detect the Earth Tide from the Sun and Moon Venice Neutrino Telescope

19. Science Runs A Measure of Progress Milky Way Virgo Cluster Andromeda NN Binary Inspiral Range E8 ~ 5 kpc S1 ~ 100 kpc S2 ~ 0.9Mpc S3 ~ 3 Mpc Design ~ 14 Mpc Venice Neutrino Telescope

20. Astrophysical Sources • 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” Venice Neutrino Telescope

21. Detection of Periodic Sources • Pulsars in our galaxy: “periodic” • search for observed neutron stars • all sky search (computing challenge) • r-modes • Frequency modulation of signal due to Earth’s motion relative to the Solar System Barycenter, intrinsic frequency changes. • Amplitude modulation due to the detector’s antenna pattern. Venice Neutrino Telescope

22. Two Search Methods • Frequency domain • Best suited for large parameter space searches • Maximum likelihood detection method + Frequentist approach • Time domain • Best suited to target known objects, even if phase evolution is complicated • Bayesian approach Early science runs --- use both pipelines for the same search for cross-checking and validation Venice Neutrino Telescope

23. Directed Pulsar Limits on Strain Crab pulsar Marginalized Bayesian PDF for h S1 J1939+2134 S2 1 PDF 0 J1910 – 5959D: h0 = 1.7 x 10-24 h95 strain Red dots: pulsars are in globular clusters - cluster dynamics hide intrinsic spin-down properties Blue dots: field pulsars for which spin-downs are known Venice Neutrino Telescope

24. Directed Pulsar Search 28 Radio Sources Venice Neutrino Telescope

25. moment of inertia tensor gravitational ellipticity of pulsar Upper limit on pulsar ellipticity NEW RESULT 28 known pulsars NO gravitational waves e < 10-5 – 10-6 (no mountains > 10 cm R . . Venice Neutrino Telescope

26. Ellipticity Limits LIGO upper-limits from hmax J1939+2134 S1 S2 EM spin-down upper-limits • Best upper-limits: • J1910 – 5959D: h0 < 1.7 x 10-24 • J2124 – 3358:  < 4.5 x 10-6 • How far are S2 results from spin-down limit? Crab: ~ 30X Red dots: pulsars are in globular clusters - cluster dynamics hide intrinsic spin-down properties Blue dots: field pulsars for which spin-downs are known Venice Neutrino Telescope

27. Detection of Periodic Sources • Signature of gravitational wave Pulsars • Frequency modulationof signal due to Earth’s motion relative to the Solar System Barycenter, intrinsic frequency changes. • Amplitude modulationdue to the detector’s antenna pattern. ALL SKY SEARCH enormous computing challenge Venice Neutrino Telescope

28. Einstein@Home • A maximum-sensitivity all-sky search for pulsars in LIGO data requires more computer resources than exist on the planet. • The world’s largest supercomputer is arguably SETI@home • A $599 computer from Radio Shack is a very powerful computational engine. • Currently runs on a half-million machines at any given time. • With help from the SETI@home developers, LIGO scientists have created a distributed public all-sky pulsar search. Venice Neutrino Telescope

29. Einstein@Home • Versions are available for Windows, Mac, Linux. • How does Einstein@home work? • Downloads a 12 MB ‘snippet’ of data from Einstein@home servers • Searches the sky in a narrow range of frequencies • Uploads interesting candidates for further follow-up • Screensaver shows where you are currently searching in the sky • We invite all of you to join Einstein@Home and help us find gravitational waves. Venice Neutrino Telescope

30. Einstein@Home Usage Test Version had about 7K Users 5x LIGO computing capacity OFFICIAL RELEASE on 20-Feb Venice Neutrino Telescope

31. Einstein@Home Users • I'm from Germany and was interested in the mysteries of the universe since I was a little boy. I read lots of magazines about astrophysics and astronomy. When I heard about the Einstein@Home project it was no question for me to participate. • My job is to make original-sized design models of new Mercedes-Benz cars, especially the interieur. When I don't work I often play keyboards and percussions and sing some backing vocals in my cover-rock-band "Gilga-Mesh" Venice Neutrino Telescope

32. Einstein@Home Users • Hi, my name's John Slattery. I'm a 62 year old English teacher, originally from Boston, MA, currently living in Santa Fe, New Mexico where I'm tutoring, and teaching ESL. • My hobbies: fitness, camping, hiking, reading, writing, surfing the Net • I'm so very new at this; I'm not even sure what's going on. But it seemed, from the little I could understand, to be a worthwhile project. Venice Neutrino Telescope

33. Einstein@Home Users Venice Neutrino Telescope

34. Einstein@Home LIGO Pulsar Search using personal computers BRUCE ALLEN Project Leader Univ of Wisconsin Milwaukee LIGO, UWM, AEI, APS http://www.physics2005.org/events/einsteinathome/index.html http://einstein.phys.uwm.edu Venice Neutrino Telescope