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No Longer!

No Longer!.

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No Longer!

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  1. No Longer! The Double PulsarMaura McLaughlinWest Virginia University5 April 2012Collaborators: Kramer (MPiFR), Stairs (UBC), Perera (WVU), Kim (WVU), Rosen (WVU), Lyutikov (Purdue), Lomiashvili (Purdue),Gourgouliatos (Purdue), Breton (Southampton), Kaspi (McGill), Freire (MPiFR),Burgay (Cagliari), Ferdman (Manchester), Possenti (Cagliari), Lyne (Manchester), Ransom (NRAO)

  2. The Money Shot Kramer et al. in preparation

  3. A B

  4. A is eclipsed for ~ 30 seconds per orbit. Occulting region of 0.05 lt-s; 10% of light-cylinder radius (~1010 cm) of B. GBT @ 820 MHz Influence of B on A: Eclipses Can model eclipse shape to derive geometrical parameters of the system (α = 70o, θ = 130o) and measure 5o yr-1 rate of geodetic precession of B (Breton et al. 2008) Pulsed flux density Orbital phase (degrees) McLaughlin et al. 2004

  5. A is eclipsed for ~ 30 seconds per orbit. Occulting region of 0.05 lt-s; 10% of light-cylinder radius (~1010 cm) of B. GBT @ 820 MHz Influence of B on A: Eclipses Pulsar B field is dipolar! Pulsed flux density Orbital phase (degrees)

  6. Influence of A on B: Bright Phases B bright at only two orbital phases. GBT @ 820 MHz Kramer and Stairs 2008

  7. Influence of A on B: Bright Phases B bright at only two orbital phases. Due to A distorting B’s magnetosphere (Lyutikov 2005). GBT @ 820 MHz Kramer and Stairs 2008

  8. Influence of A on B: Bright Phases Bright phases evolve due to periastron advance (17o yr-1) and geodetic precession (5o yr-1) . Perera et al. 2010 Kramer and Stairs 2008 Light curves of B during BP1.

  9. B shows dramatic pulse profile changes across orbit and with time. Geodetic Precession: Pulse Profiles Pulse profiles of B during BP1 March 2008: Bye Bye B  Perera et al. 2010

  10. Geodetic Precession: Pulse Profiles We can fit the pulse profile evolution to a geometrical model. We find similar geometrical parameters as from eclipse model fitting (α = 70o, θ = 130o). Emission beam is elliptical (a/b = 2.6) and only partially filled. Radio reappearance is expected to occur in 2024. Perera et al. 2010

  11. Influence of A on B: Emission Heights Bow shock at 4 x 109 cm (30% RLC) from B. Can trace the magnetic field lines structure within this bow shock, given solved geometry. Will change with orbital phase and B spin phase. Can estimate a magnetic field of 6 x 1011 G, half of timing-derived value. Perera et al. submitted

  12. Influence of A on B: Emission Heights Can estimate emission heights given magnetic field structure and shape of pulse profile. Perera et al. submitted

  13. Application: NS-NS Inspiral Rates DP will merge in 85 Myr. Can now incporate selection effects for B. Kim et al. submitted

  14. Application: NS-NS Inspiral Rates DP will merge in 85 Myr. There are roughly 1400(+4100,-900) DP-like systems in MW. Given 445 Mpc horizon distance for Advanced LIGO, we calculate a detection rate of 8(+11,-5) yr -1. J0737 B1534 B1913 Kim et al. submitted Kim et al. submitted

  15. Influence of A on B: Drifting Features GBT @ 820 MHz Single pulses from A Single pulses from B Drifting McLaughlin et al. 2004

  16. Influence of A on B: Drifting Features McLaughlin et al. 2004 The drifting is a direct signature of the influence on the EM radiation from A on B! Direct Evidence that B’s emission is modulated by A’s EM radiation! Direct Evidence that B’s emission is modulated by A’s EM radiation! Direct Evidence that B’s emission is modulated by A’s EM radiation! Direct Evidence that B’s emission is modulated by A’s EM radiation!

  17. Influence of A on B: Drifting Features Through a geometrical model (Freire et al. 2009, Rosen et al. in preparation), can fit for: • 1) Rotation direction of A 2) Emission altitude in B, ε 3) Angle between A’s radio and EM beam, ϕe Response Delay =

  18. Influence of A on B: Drifting Features Through a geometrical model (Freire et al. 2009, Rosen et al. in preparation), can fit for: 1) Rotation direction of A likely in direction of orbit 2) Emission altitude in B, ε ~500 RNS (within the bow shock) 3) Angle between A’s radio and EM beam, ϕe small and varying Response Delay =

  19. Conclusions After nine years, the Double Pulsar is still providing new insights. We can fit B pulsar data with an elliptical, partially filled beam and can determine the geometrical parameters of the system. B is expected to reappear in 2024. We see evidence for the direct modulation of B pulsar emission through the EM field of A. We estimate minimum B emission heights of ~100 RNS through geometrical modeling and ~500 RNS through drift-band fitting. We estimate an Advanced LIGO NS-NS inspiral detection rate of 8(+11,-5) yr -1. More relativistic binaries essential for better statistics. Advances in timing and GR tests will come with improved B timing precision.

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