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With former postdoc: Guoqiang Ding & current postdoc: Shanshan Weng PowerPoint Presentation
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With former postdoc: Guoqiang Ding & current postdoc: Shanshan Weng

With former postdoc: Guoqiang Ding & current postdoc: Shanshan Weng

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With former postdoc: Guoqiang Ding & current postdoc: Shanshan Weng

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  1. On the nature of Z-sources and Atoll-sources: interaction between NS magnetosphere and accretion diskShuang-Nan ZHANG Key Laboratory of & Center for Particle AstrophysicsInstitute of High Energy PhysicsChinese Academy of Scienceszhangsn@ihep.ac.cn With former postdoc: Guoqiang Ding & current postdoc: Shanshan Weng

  2. After Narayan’s exciting talk yesterday, I was asked why and how I did the BH spin measurement with continuum spectral modeling. • So I just start from here…. High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  3. A new imaging method with GRO/BATSE High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  4. Discovery of the 2nd microquasar GRO J1655-40 • Circular No. 6046 S. N. Zhang, C. A. Wilson, B. A. Harmon, G. J. Fishman, R. B. Wilson, W. S. Paciesas, M. Scott, and B. C. Rubin report for the Compton Gamma Ray Observatory BATSE team: "An x-ray nova has been observed at R.A. = 16h55m, Decl. = -40o.5 (equinox 2000.0; error radius 0o.3). The source (GRO J1655-40) first appeared in data from July 27 and has increased to its present level of about 1.1 Crab (20-100 keV) on Aug. 1. Significant flux is observed to 200 keV. A power law with a spectral index of -3.15 +/- 0.07 fits the data well from 20 to 200 keV. Pulsed emission is not seen in the period range from 3 to 300 s at a limiting sensitivity of about 10 percent of the steady flux. No previously-cataloged x-ray source is known at this location. It has also been determined that the nearby x-ray pulsar OAO 1657-415, currently observed by BATSE, is not responsible for the observed emission." High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  5. My first paper on GRO J1655-40 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  6. BH mass determination assuming a non-spinning BH High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  7. First suggestion for BH spin (0.95) of GRO J1655-40 Rashid Sunyaev suggested me to address the X-ray mass and optical mass discrepancy. I suggested to blame the BH spin, and Rashid was thrilled by this and suggested me to further explore this. High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  8. My first BH spin paper Jerry Fishman gave the title; Jan van Paradijs and Nick White proof read the paper before submission. High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  9. 6 from Narayan’s army in 2010 alone. High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  10. Interaction between compact objects and accretion disks • BHs: inner stable circular orbit in GR BH spin • Zhang et al 1997 Narayan+: working very well!!!! • Congratulations to Narayan and his army, and many thanks for generously giving me the credit! • NSs: W. Cui: magnetosphere-diskNS magnetic field • Zhang et al 1998: Propeller effect in Aql X-1108 G • Planned to work with John Wang of UMD, sadly… • Chen, Zhang & Ding 2006: Propeller effect in 4U1608-522 2x108 G • Now beyond propeller and also for Z-sources… • How and why atoll and Z-sources behave the way they do? High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  11. Distributions of Low-Mass and High-Mass X-Ray Binaries LMXB: old population, in globular clusters and galactic center HMXB: young population, in the galactic plane High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  12. Physics Properties of Low-Mass and High-Mass NS XRBs High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  13. Color-Color Diagrams of two typical atoll-sources Lin, Remillard & Homan 2007 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  14. Two typical Z-sources Lin, Remillard & Homan 2009 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  15. The first transient Z-source XTE J1701-462 Lin, Remillard & Homan 2009 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  16. Atoll-states Lin, Remillard & Homan 2009 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  17. Nature of Z- and atoll-sources? • All previously known Z-sources are much more luminous than atoll-sources on average. • Does disk accretion rate distinguish between Z- and atoll sources? • And if so, why? • However the peak luminosity of transient atoll-sources can be higher than Z-sources at less luminous state. • A second parameter is involved. Is NS magnetic field of Z-sources higher than that of atoll-sources? • But NS magnetic field is difficult to measure. • For non-bursting and non-pulsating sources, any evidence for NS? High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  18. Gas pressure dominated disk-magnetosphere model Signature of NS magnetosphere, but never observed! Lamb, Pethick & Pines (1973) High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  19. Radiation pressure dominated disk-magnetosphere model Radiation pressure dominates over gas pressure @>~0.3 Edd Most Z-sources spend most of their lives ~ Edd High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  20. Expected relation of radiation pressure dominated disk Lamb, Pethick & Pines (1973) Without knowing the disk structure a prior, i.e., , only Ba , can be inferred from observations (with disk-BB model) directly. If no disk structure evolution (thin disk: Shakura & Sunyaev 1973), but never observed! Shakura & Sunyaev (1973): in a radiation pressure dominated disk, . Considering radiation driven outflows, the inflowing disk’s thickness High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  21. Numerical simulation of supercritical accretion onto NS Ohsuga 2007 Ohsuga 2007 Stronger outflows for NS supercritical accretion High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  22. Numerical simulation of supercritical accretion onto NS Ohsuga 2007 Ohsuga 2007 Similar disk but with an accretion shell for NS supercritical accretion High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  23. Color-color diagrams for the data we used for XTE J1701-462 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  24. XTE J1701-462 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  25. High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  26. Spectral model DiskBB (accretion disk) + BB (NS surface) + Fe Kα + BPL DiskBB BB DiskBB BB BPL Fe Kα Fe Kα High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  27. Bifurcation of total luminosity High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  28. Thick disk + magnetosphere model disk vertical structure evolution NS Surface partially blocked by thickened disk High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  29. Measure the surface B of the NS in XTE J1701-462 At super-Edd, inner disk is spherized (the accretion shell), thus Unambiguous evidence for NS magnetosphere! High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  30. Atoll-source 4U1608-522 RXTE/PCA 2-60 keV flux Swift/XRT 0.6-10 keV flux ASM daily average High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  31. (8.6–18.0) keV/(5.0–8.6) keV (3.6–5.0) keV/(2.2–3.6) keV High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  32. Comparison between 4U1608-522 & XTE J1701-462 4U1608-522 Rin expanding Rin expanding ADAF/ADIOS outflow? Constant Rin Lin, Remillard & Homan 2007 Powerlaw dominates Estimation for the NS surface B of 4U1608-522 Consistent with (1.4-1.8)x108 G in Chen, Zhang & Ding 2006, ApJL, 650, 299 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  33. Cir X-1: Z-source High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  34. Cir X-1: Z-source High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  35. Inner disk radius and Ba evolution in Cir X-1 Normal and flaring branches XTE J1701-462 Horizontal Branch Problem: is for gas-pressure dominated disk-magnetosphere interaction, then how can this happen at super-Eddington? Speculation: changes very rapidly, such that the disk vertical structure has no time to respond to radiation pressure? High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  36. Accretion rate and magnetic field of atoll & Z sources Z-sources are much brighter and have much stronger NS surface magnetic fields than atoll-sources. High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece

  37. Nature of Z- and atoll-sources: two parameter picture • Why do they avoid the diagonal line? • Companion & NS conspire? • But how do they know each other? • Companion & NS born together? • But what about recycled ms radio pulsars? Z-zone Cir X-1 Atoll-zone XTE J1701-462 Aql X-1 4U 1608-522 High Energy View of Accreting Objects , Oct 5-14, 2010, Crete, Greece