19 years timing of j1713+0747 weiwei zhu nanograv timing group 2012-08-22
TRANSCRIPT
19 Years Timing of J1713+0747
Weiwei ZhuNANOGrav Timing Group
2012-08-22
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, Pb = 68 day (Foster et al. 1993)
Mark3(441ns) ABPP(86ns) Mark4(152ns) ASP(52ns) GASP(136ns)
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.
Gravitational Wave Background Level
• 5-Year single pulsar GW upper limit A1~10-14 (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
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;
0.3Mʘ1.4Mʘ
(Stairs et al. 2005, Gonzalez et al. 2011)
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)
Measuring --Orbital Inclination & Orientation
Shapiro Delay:Mpulsar = 1.40.1 Mʘ
MWD = 0.300.02 Mʘ
i = 71 1
Measuring :𝑥 ̇�Ω = 93
Other Parameters:PMRA,PMDEC V
Ω
i
Kopeikin 1996)
Test Fundamental Physics Principles
• (95%CL; Stairs et al. 2005; Gonzalez et al. 2011 based on 27 binary MSPs, including J1713)
• (95%CL; Stairs et al. 2005; Gonzalez et al. 2011 )
Markov Chain Monte Carlo estimation of the parameters
Blue: Other pulsar binaries (Gonzalez et al 11)Red: J1713+0747
Einstein’s GR:
(:Kinematic effect; :Gravitational Wave)
All consistent with Einstein’s general theory of relativity
[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 Pb – test Einstein’s GR
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:
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
Thank You