2. LIGO-G050002-00-Z Einstein@home: how to find gravity waves with your home PC Michael Landry LIGO Hanford Observatory California Institute of Technology Say Hello to Einstein@home LHO June 8, 2005 Photo credit: NASA/CXC/SAO

3. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 2 Detecting a signal Greg has talked about sources Now let’s talk about detection If our detector was not moving with respect to a star, gravity waves would sound like a single tone Gravity waves from dense spinning stars are Doppler shifted by the motions of the Earth relative to the star (FM) Gravity waves are also amplitude modulated because interferometer sensitivity varies with direction (AM) Waves get Doppler shifted from relative motion

4. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 3 Simulation: Gravitational Waves Seen & Heard Play Me (AM & FM modulation greatly exaggerated)

5. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 4 Detecting a signal Steps in detection: »Guess at what the signal might look like »Compare your guess to your data from your interferometer »This is called matched filtering »If you don’t find a signal, keeping guessing and comparing

6. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 5 : Data from detector

7. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 6 : Data from detector : “Guess” at signal

8. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 7 : Data from detector

9. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 8 : Data from detector : “Guess” at signal

10. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 9 : Data from detector : “Guess” at signal

11. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 10 : Data from detector : “Guess” at signal

12. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 11 : Data from detector : “Guess” at signal

13. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 12 : Data from detector : “Guess” at signal Match!!

14. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 13 Einstein@home Installation Screensaver Web pages Getting help APS webpage http://www.physics2005.org/events/einsteinathome/index.html Einstein@home webpage http://einstein.phys.uwm.edu/

15. LIGO-G050002-00-Z Landry - Einstein@home, 8 Jan 2005 14 Summary Run Einstein@home on your home PC! Tell your friends! Tell your enemies! You may be the first person in history to detect gravity waves on your computer! Pick up a pamphlet at the back of the auditorium with instructions on how to load the screen saver If you have a survey attached to the bottom of your chair, please fill this out and drop it in the box on the way out the door Cookies available in the foyer