1. 19 Years Timing of J1713+0747 Weiwei Zhu NANOGrav Timing Group 2012-08-22

2. J1713+0747 One of the longest/best timed pulsars – ~52ns time precision and improving, (Demorest et al. 2012, this work) – 19 years total time span P= 4.6ms, P b = 68 day (Foster et al. 1993) Mark3 (441ns) ABPP (86ns) Mark4 (152ns) ASP (52ns) GASP( 136ns )

3. What can we do with this pulsar? Constrain gravitational wave background level Great laboratory for testing fundamental physics principles – Strong equivalence principle – Lorenz invariance/conservation of momentum Excellent strong-field test for Einstein’s general relativity and constrains for alternative theories.

4. Gravitational Wave Background Level 5-Year single pulsar GW upper limit A 1 ~10 -14 (Demorest et al. 2012), a factor of a few higher than the limit from all pulsars. A new single-pulsar GW background limit may be derived from our 19 years timing solution. Demorest et al.2012

5. Testing Fundamental Physics Principles -- Test Strong Equivalence Principle Damour & Schafer 1991; Wex 1997, 2000; Bell & Damour 1996; Stairs 2003; Splaver et al. 2005; Gonzalez et al. 2011; 0.3M ʘ 1.4M ʘ (Stairs et al. 2005, Gonzalez et al. 2011)

6. Existence of A Preferred Frame? A preferred Frame breaks down Lorenz Invariance/conservation of momentum. Acceleration and forced eccentricity. Preferred Frame (Stairs et al. 2005, Gonzalez et al. 2011)

7. Ω i

8. Test Fundamental Physics Principles Markov Chain Monte Carlo estimation of the parameters Blue: Other pulsar binaries (Gonzalez et al 11) Red: J1713+0747

9. [J0437-4715, Deller et al. 08] [J1012+5307, Lazaridis et al. 09] [J1738+0333, Freire et al. 12] [J1713+0747, this work, 68%CL] 52ns precision/68 day orbital period  measuring the slowest fractional change over time The Changing P b – test Einstein’s GR

10. Constrain Alternate Theory of Gravitation Constraint based on J1012 J1738 and J1713 Lunar Laser Ranging; Hofmann et al. 2010 J0437&J1738; Freire et al 2012 J0437&J1738; Freire et al 2012 Our Constraint based on J1012, J1738 and J1713:

11. Summary As one of the best high-precision pulsars, J1713+0747 can: – strongly constrain gravitational wave background level – test fundamental physical principles – test/constrain theories of General Relativity

12. Thank You