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Pulsar Science with the SKA

Jim Cordes & Michael Kramer International SKA Conference 2003 Geraldton 30 July 2003. Pulsar Science with the SKA. Pulsar Science. Extreme matter physics 10x nuclear density High-temperature superfluid & superconductor B ~ B q = 4.4 x 10 13 Gauss Voltage drops ~ 10 12 volts

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Pulsar Science with the SKA

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  1. Jim Cordes& Michael Kramer International SKA Conference 2003 Geraldton 30 July 2003 Pulsar Science with the SKA Pulsar Science with the SKA

  2. Pulsar Science • Extreme matter physics • 10x nuclear density • High-temperature superfluid & superconductor • B ~ Bq = 4.4 x 1013 Gauss • Voltage drops ~ 1012 volts • FEM = 109Fg = 109 x 1011FgEarth • Relativistic plasma physics (magnetospheres) • Tests of theories of gravity • Gravitational wave detectors • Probes of turbulent and magnetized ISM (& IGM) • End states of stellar evolution Pulsar Science with the SKA

  3. Why more pulsars? • Discover rare, extreme objects (odds  Npsr) • P < 1 ms P > 8 sec • Porb < hours B >> 1013 G (link to magnetars?) • V > 1000 km s-1 strange stars? • NS-NS and NS-BH binaries, planets • Extragalactic pulsars • Galactic center pulsars orbiting Sgr A* black hole Large N  Galactic tomography • Large Npsr  Galactic tomography of B + B, ne + ne • Branching ratios for compact object formation: • NS (normal, isolated) • NS (recycled, binaries) • NS (magnetar) • BH (hypernovae) • Strange stars? Pulsar Science with the SKA

  4. How to do it? • Find them • Time them • VLBI them Pulsar Science with the SKA

  5. Blind Surveys with SKA • (pulsars, transients, ETI) • Number of pixels needed to cover FOV: Npix~(bmax/D)2 ~104-109 • Number of operations Nops~ petaops/s • Post processing per beam: e.g. standard pulsar periodicity analysis Dedisperse (~1024 trial DM values) + FFT + harmonic sum (+ orbital searches + RFI excision) • Requires signal transport of individual antennas to correlator • 104 beams needed for full-FOV sampling Pulsar Science with the SKA

  6. Sensitivity Calculations • Pulse smearing effects • Dispersive arrival times • Scattering • Orbital • Instrumental • Luminosity function for pulsars (> 5 orders of magnitude) = beaming + beam luminosity calculatedusing NE2001 (Cordes & Lazio 2003) Pulsar Science with the SKA

  7. Pulsar Searching With SKA vs Arecibo Dmax = (Lp / Smin1)½Nh¼ Fourier search Nh = # harmonics detectable Pulse smearing effects from interstellar scattering (also, orbital smearing in NS-BH binaries, etc.) Pulsar Science with the SKA

  8. SKA pulsar survey 64 s samples 1024 channels 600 s per beam ~104 psr’s Pulsar Science with the SKA

  9. Summary on Pulsar Searching • SKA can perform a Galactic census of neutron stars that will surpass previous surveys by a factor > 10. • The discovery space includes exotic objects that provide opportunities for testing fundamental physics. • Pulsar searches place particular demands on the ability to do full FOV sampling at high time resolution (64 s) with 1024 channels over > 400 MHz at 1-2 GHz. • High frequencies (> 10 GHz) are needed for Galactic center searches to combat scattering. • Further simulations are needed that use detailed information from existing pulsar surveys and particular SKA configurations. Pulsar Science with the SKA

  10. electron distribution Magnetic field Also: Scintillation  Resolving Magnetosphere! Post-discovery Science Very wide range of applications: • Galactic probes:Interstellar medium/magnetic field • Star formation history • Dynamics, grav. potential Pulsar Science with the SKA

  11. Post-discovery Science Very wide range of applications: • Galactic probes:Interstellar medium/magnetic field • Star formation history • Dynamics, grav. potential • Extragalactic pulsars:Stellar formation & population, IGM Giant pulses Extragalactic pulsars Probing the local group! Pulsar Science with the SKA

  12. Post-discovery Science Very wide range of applications: • Galactic probes:Interstellar medium/magnetic field • Star formation history • Dynamics, grav. potential • Extragalactic pulsars:Stellar formation & population, IGM • Solid State Physicsunder extreme conditions Equation-of-State Glitches NS structure Pulsar Science with the SKA

  13. Post-discovery Science Very wide range of applications: • Galactic probes:Interstellar medium/magnetic field • Star formation history • Dynamics, grav. potential • Extragalactic pulsars:Stellar formation & population, IGM • Solid State Physicsunder extreme conditions • Tests of theories of gravity, e.g. Black Hole properties! Pulsar Science with the SKA

  14. Post-discovery Science Very wide range of applications: • Galactic probes:Interstellar medium/magnetic field • Star formation history • Dynamics, grav. potential • Extragalactic pulsars:Stellar formation & population, IGM • Solid State Physicsunder extreme conditions • Tests of theories of gravity, e.g. Black Hole properties! • Detection of gravitational wave background Pulsar Timing Array: Look for global spatial pattern in timing residuals! Pulsar Science with the SKA

  15. Advanced LIGO Pulsars LISA Gravitational Wave Background • Sources: Binary BHs, Galaxy Formation, Strings, Big Bang • Pulsars = Arms of a huge gravitational wave detector • Sensitivitycomplementary to LIGO and LISA Pulsar Science with the SKA Backer (priv. comm)

  16. Wide bandwidth (20-50%), polarization 1 s (or even 10-100 ns??) Multi-frequency: 400-10000 MHz Strong pulsars: stabilization time-scale dominating Weak pulsars: SNR dominating Multiple FOVs! Precision Pulsar Timing with the SKA Consider: • Fast(!) sampling • High sensitivity • Systematics, e.g. solar system ephemeredes, • time standards • Interstellar weather • Multipath scattering • Timing noise (?) • Profile stability Pulsar Science with the SKA

  17. Independent FOVs: About 12,000 pulsars, ~1300 MSPs Sources (=beams) per FOV Multiple FOVs:Initial Simulation Results Simulated Population: Pulsar Science with the SKA

  18. Multiple FOVs:Initial Simulation Results Simulated Population: Required time for one(!) timing point: All Pulsars Pulsar Science with the SKA

  19. Multiple FOVs:Initial Simulation Results Simulated Population: Required time for one(!) timing point: Millisecond Pulsars Pulsar Science with the SKA

  20. Summary:Pulsars with the SKA • Overwhelming science case: • New quality due to both leap in numbers and timing precision • “Modest” frequency coverage but large bandwidth • Large number of simultaneous beams/FOVs desirable • Detailed requirements different for searching & timing • - both modes are necessary to obtain science!! • Configuration: sensitive core but with very large baselines • (to enable astrometry out to 10 kpc) • Significant post-processing requirements! • Large instantaneous  at 2 GHz • (contiguous or separated FOVs) • searching: 50 s sampling full FOV • timing: 1 s sampling pencil beam • capability of  up to 10 to 15 GHz • (less than 1 SKA)  Hybrid Design: Pulsar Science with the SKA

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