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A possible pulsar science of FAST -70 th Birthday of prof.Dick Guojun Qiao

A possible pulsar science of FAST -70 th Birthday of prof.Dick Guojun Qiao. Outline. Among three pulsar giants, Dick helped us most!. Dick helped us not only for pulsar research, but also for young people having a sit there. Dick: a friend of our people. Outline.

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A possible pulsar science of FAST -70 th Birthday of prof.Dick Guojun Qiao

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  1. A possible pulsar science of FAST -70th Birthday of prof.Dick GuojunQiao

  2. Outline

  3. Among three pulsar giants, Dick helped us most!

  4. Dick helped us not only for pulsar research, but also for young people having a sit there.

  5. Dick: a friend of our people

  6. Outline

  7. We appreciate the long term cooperations on pulsar research with Dr. Dick Manchester Parkes obs of pulsar polarization profiles • 45 pulsars at 1560MHz by Wu XJ, Manchester, Lyne, Qiao 1993, MNRAS 261,630 • 29 pulsars at 660MHzand 40 pulsars at 1440MHz by Qiao GJ, Manchester, Lyne, Gould, 1995, MNRAS 274, 572 • 66 pulsars at 435, 660, 1500MHz by Manchester, Han & Qiao, 1998, MNRAS　295, 280 • Circular polarization: Han JL, Manchester, Xu, Qiao 1998, MNRAS 300, 373 ...........

  8. Group of NAOC

  9. Dick & Wu: Wang Na’s Advisor for PhD

  10. JinLin Han & Dick Manchester have observed several hundreds of pulsars with Parkes 64m for their polarization and rotation measures. Their data are crucial to delineate the Galactic magnetic fields.

  11. Pulsars as probes for magnetic field • Polarized. Widely spread in our Galaxy. Faraday rotation: • Distances estimated from pulse dispersion: • <===the delay tells DM • the rotation of position • angles tells RM value===> • Average field strength is

  12. To study halo field: unique RM distribution Pulsars • The largest edge-on Galaxy in the sky • Pulsars and extragalactic radio sources as probes

  13. Possible pulsar science of FAST • We have not experience => • Need your help: • Dick Manchester, • G. Hobbs • J.M. Cordes • ……

  14. Possible pulsar science of FAST

  15. WIDE RADIO BEAMS FROM γ -RAY PULSARS Ravi, Manchester & Hobbs,2010 G-Gamma-ray R-radio Θc-common Θg-gamma Θr-radio

  16. Possible pulsar science of FAST

  17. Possible test of SS and NS 1. Rotational period: SS can reach sub-millisecond2. Mass-radius.3. Solid strange star or NS?4. Binding energy of the surface. Bare strange star.Can we take a test from radiation: The difference between vacuum gap and free flow?

  18. P<0.5 ms Quark star， Du,Xu,Qiao,Han,2009, MN Spin frequency Stable axis-symmetric spin (GW radiation) P = 0.89ms (2007)? XTE 1739 Sub-ms periods (P < 1 ms) P = 1.4ms (2006) P = 1.6ms (1982) PSR 1748 PSR 1937 P = 33ms (1968) P ~ 1s (1967) Crab Xu,2008

  19. Mass-Radius relation and spin limit • QSs : can be with small mass & radius? Lattimer & Prakash (2004) ~2M☉ ~10km 0.2 M☉ “SubmsPSRs” http://vega.bac.pku.edu.cn/rxxu R. X. Xu

  20. Thank you !

  21. Possible pulsar science of FAST

  22. M > 3 M⊙: black hole ! Casares, stro-ph/0612312,

  23. Can we find an Evidence of Event Horizon? It’s a black hole. ? It’s black, and it looks like a hole. I’d say it’s a black hole.

  24. Free Precession of a Radio Pulsar Stairs et al. 2000 • B1828–11: • Systematic timing residuals • Periods of 1000, 500 and 250 days • Pulse shape and torque correlated

  25. Free Precession of a Radio Pulsar BUT: Free precession isnot expectedin case of pinned vortices in super-fluid interior!

  26. Solid quark stars: Observational hints… Xu 2003 “Solid Quark Stars?” ApJ, 596, L59-L62 Zhou, Xu et. 2004 Astropart. Phys., 22, 73 Xu et al., 2006 MN, 373, L85 Zhu & Xu, 2006 MN, 365, L16 Xu, 2006, Astropart. Phys., 25, 212 Peng & Xu 2008, MN, 384, 1034 Xu, 2009, J. Phys. G: Nucl. Part. Phys., 36, 064010 Lai & Xu 2009, Astropart. Phys., 31, 128 Lai & Xu 2009, MN, 398, L31

  27. An accretion disk model for periodic timing variations of pulsars (Qiao, Xue,Xu, Wang, Xiao. 2003, A&AL)

  28. An accretion disk model for periodic timing variations of pulsars (Qiao, Xue,Xu, Wang, Xiao. 2003, A&AL)

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