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Bronek Rudak (CAMK) Jarek Dyks (CAMK) Michał Frąckowiak

Pulsar studies in the high energy domain. Bronek Rudak (CAMK) Jarek Dyks (CAMK) Michał Frąckowiak Gottfried Kanbach (MPE) Aga Słowikowska (U. of Crete). „. , X-ray binaries, accretion disks and compact objects” Oct 7 - 13, 2007.

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Bronek Rudak (CAMK) Jarek Dyks (CAMK) Michał Frąckowiak

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  1. Pulsar studies in the high energy domain Bronek Rudak (CAMK) Jarek Dyks (CAMK) Michał Frąckowiak Gottfried Kanbach(MPE) Aga Słowikowska(U. of Crete) „ , X-ray binaries, accretion disks and compact objects” Oct 7 - 13, 2007

  2. - What do we know about high energy radiation from pulsars? • How do the observations constrain pulsar models? • Why we need GLAST, H.E.S.S.II and … POGOLite ? • For the purpose of this talk: • high energy = optical, UV, X-rays, gamma rays • with emphasis on gamma rays

  3. The ATNF Pulsar Database: ~1770 objects

  4. Why do pulsars radiate in high energy? • 1) Pulsars are rotating, strongly • magnetized neutron stars; • they can act as unipolar inductors • 2) The maximum potential drop can reach • Vmax 7  1012 B12 P-2 Volts, • i.e. for young pulsars Vmax can exceed 1016 Volts. • 3) This potential drop can accelerate charged particles to ultrarelativistic energies • emitting high energy photons. • Important: • The size and shape of the accelerators (the gaps) is model dependent.

  5. Pulsars across electromagnetic spectrum:light curves and spectra D.J. Thompson 2003

  6. Harding et al., 2001 Vela pulsar

  7. D.J. Thompson 2003

  8. H.E.S.S. results (F. Schmidt et al., 2005)

  9. Venter & de Jager 2004

  10. Radiative processes in strong magnetic field 1. Curvature radiation 2. Inverse Compton Scattering (resonant + non-resonant) 3. Magnetic pair creation ( 1γ e± ) 4. Photon-photon pair creation ( 2γ e± ) 5. Synchrotron radiation 6. Photon splitting ( 1γ 2γ )

  11. Examples of models of phase-averaged energy spectrum of B0833-45 (Vela)

  12. Fig. by A.K. Harding

  13. Dyks & R. 2003 Two-pole caustic –slot gap model outward emission along last open field lines inward emission along last open field lines

  14. Vela Two-pole caustic model and outer gap modelvs.Vela

  15. Polarimetry of the Crab pulsar - Słowikowska et al. 2006 (OPTIMA) Polarization Degree Position Angle DC  2% of MP p  33%,   119º

  16. Light curves and polarisationcharacteristics within theframework of three high energy magnetosphericemission models of pulsars Dyks et al. 2004

  17. T. Kamae et al.2007 • The Polarised Gamma-ray Observer – • Lightweight Version • POGOLite • a baloon-borne polarimeter • Energy range: 25 – 80 keV • First flight in 2009

  18. Kamae et al. 2007 Main pulse of the Crab pulsar by three models with 6 hour of simulated observations by POGOLite

  19. Harding, Muslimov & Zhang 2002 What about pulsars which don’t have slot gaps?

  20. Taken from S. Ritz (2007)

  21. W. Hofmann (2007)

  22. W. Hofmann (2007)

  23. Rotation leads to non-axisymmetric magnetic absorption

  24. For GLAST P = 0.1s

  25. Peak-to-peak separation changes w. energy in presence of magnetic absorption For GLAST

  26. VELA - polar cap model #1: super-exponential cutoff in the spectrum For GLAST

  27. VELA - polar cap model #2: BUT exponential cutoff in the spectrum ! For GLAST

  28. HE spectra of millisecond pulsars Kuiper & Hermsen2003

  29. PSR J0218+4232 – the first millisecond pulsar in gamma-rays P = 2.32 ms Bpc = 0.001 TG d = 5.85 kpc BeppoSAX points - Mineo et al.. 2000 EGRET points - Kuiper et al.. 2000

  30. Simple polar gap model for gamma rays in millisecond pulsars Example: P = 2.3 ms B = 0.001 TG inclination: α = 60°

  31. Two models of J0437-4715: photon maps and light curves above 100 MeV For GLAST  = 35,  = 40  = 20,  = 16

  32. A model ofB1821-24P = 3.1 ms, B = 0.002 TG, d = 5.1 kpc = 50o z = 45o For GLAST photon flux above 100 GeV For H.E.S.S. II

  33. Model of J0218+4232 w. mini-caustics (slot gaps),  = 25,  = 47

  34. GLAST H.E.S.S.

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