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MIT Workshop on Magnetized Accretion Disks

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MIT Workshop on Magnetized Accretion Disks

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  1. This presentation will probably involve audience discussion, which will create action items. Use PowerPoint to keep track of these action items during your presentation • In Slide Show, click on the right mouse button • Select “Meeting Minder” • Select the “Action Items” tab • Type in action items as they come up • Click OK to dismiss this box • This will automatically create an Action Item slide at the end of your presentation with your points entered. MIT Workshop on Magnetized Accretion Disks October 19 & 20, 2006 Supported by: MIT-France Program CEA Saclay, France MIT Kavli Inst. for Astrophysics & Space Research MIT Dept. EE&CS RXTE Project

  2. Workshop Handouts & Logistics • Schedule: (4 sessions) • Name Tag • List of Participants • MIT wireless instructions for visitors • Thursday dinner? …stay here after session 2 Legal Seafoods? Cambridge Brewery?

  3. This presentation will probably involve audience discussion, which will create action items. Use PowerPoint to keep track of these action items during your presentation • In Slide Show, click on the right mouse button • Select “Meeting Minder” • Select the “Action Items” tab • Type in action items as they come up • Click OK to dismiss this box • This will automatically create an Action Item slide at the end of your presentation with your points entered. X-ray States of Black Hole Binaries: Observations and Physical Models Ron Remillard MIT Kavli Center for Astrophysics and Space Research

  4. Workshop Motivations • Assess status of BH accretion physics General relativity astrophysics at 10 Rg? X-ray states versus accretion models critical need for steep power-law / QPO paradigm discussions of magnetism in accretion disks • Communicate: observers ; theorists ; GR/MHD physicists 1.5 years since last UCSB program on BH theory informal format for hard results + views & intuitions motivate future work

  5. Active X-ray States of BH Binaries • Thermal State: thermal spectrum ; L aT4 ; no QPOs Paradigm: Heat from weakly magnetized accretion disk • Hard State: flat, cutoff power law ; cool disk ; some QPOs Concept: Compton/synchrotron from steady jet (+ ADAF?) Jets are confined by magnetic fields from the disk? • Steep Power Law: thermal + SPL + QPOs + HFQPOs ?? Magnetized Accretion Disk ; Accretion Torus ??

  6. Black Hole X-ray Nova GRO J1655-40 First known outbursts: 1994-95; () 1996-97; 2005 Dynamical black hole binary 6.3 (+0.5) Mo Relativistic Jets in 1994 ~Radio-quiet, 1996-97, 2005

  7. Black Hole X-ray Nova GRO J1655-40  Different X-ray States

  8. Observation Reviews & Global Studies Done & Gierlinski 2003MNRAS, 342, 1041 Fender 2006Compact Stellar X-ray Sources, Ch. 9 Fender & Belloni 2004ARAA, 42, 317 Charles & Coe 2006Compact Stellar X-ray Sources, Ch. 5 McClintock & Remillard 2006Compact Stellar X-ray Sources, Ch. 4 Psaltis 2006 Compact Stellar X-ray Sources, Ch. 1 Remillard & McClintock 2006ARAA, 44, 49 van der Klis 2006Compact Stellar X-ray Sources, Ch. 2 Zdziarski & Gierlinski 2004PThPS, 155, 99

  9. X-ray States of BHBs • ThermalState: fdisk > 75%; rms < 0.075 ; no QPOs (amax < 0.5%) • inner accretion disk

  10. X-ray States of BHBs • ThermalState: • classical disk model: T(r) ~ r-3/4 L(r) ~ r-2

  11. Heat from Accretion Disk ? modified disk blackbody blackbody energetics GR/Keplerian velocities? GX339-4 Relativistic Fe line e.g. Miller et al. 2004; but see Merloni & Fabian 2003 Kubota & Done 2004; Gierlinski & Done 2004 T(r)ar-p; p ~ 0.7 (Kubota et al 2005) (GR tweak of p=0.75)

  12. Thermal State Paradigm ? Spectral shape and luminosity evolution consistent with thermal-disk model: Hot gas in Keplerian orbits + efficient dissipation GR/MHD Simulations: Plasma + Magneto-Rotational Instability (MRI): ~Keplerian orbits ; high b = Pgas / (B2/8p)  Thermal Radiation from a Weakly Magnetized Disk Alternatives:low b inner disk (external seed B) ? Plasma Rings (Coppi & Rousseau 2006) ? GR MHD: Stronger jets with higher spin ?  Other X-ray states?

  13. Hard State of BHBs   2. Hard State fdisk < 20%; G ~ 1.4 - 2.1; rms > 0.10 steady jet(radio emission: collimated, polarized, flat spectrum)

  14. Hard State of BHBs: Steady Radio Jet  2. Hard State fdisk < 20%; G ~ 1.4 - 2.1; rms > 0.10 steady jet(radio : X-ray tight correlation Gallo et al. 2003)

  15. States of Black Hole Binaries • 3. steep power law • compact corona ? • G > 2.4; rms < 0.15 ; fdisk < 80% + QPOs (or fdisk< 50%) 1 10 100 .01 .1 1 10 100 Energy (keV) Frequency (Hz) Energy spectraPower density spectra Neutron stars (atoll type) have thermal and hard states, but they never show strong SPL spectra!

  16. Hard State of BHBs • mechanism? geometry? •  Hybrid models: • Synchrotron/Compton • (Markoff, Nowak, & Wilms 2005) • Kalemci et al. 2005 • ADAF-fed Syn./Comp.? • (Yuan, Cui, & Narayan 2005) • Cause of jets?(GRMHD?) • Vertical, external B can amplify • modest outflows of standard sims. XTEJ1118+480 (low NH)….truncated, cool disk (McClintock et al. 2001)

  17. Steep Power Law BHB Gamma Ray Bright State (Grove et al. 1998) blackbody energetics SPL |

  18. Physical Models for BHB States Energy spectraPower density spectra Statephysical picture steep power law Disk + ??  thermal hard state Energy (keV) Frequency (Hz)

  19. 3 X-ray States  3 Different Accretion Systems? • Energy spectra  YES! • Statistical Distributions in key parameters  YES! 6 BHBs [417 thermal; 214 hard; 184 SPL; 179 INT (all types)] GRO J1655-40 (1996-97) XTEJ1550-564 (4 outbursts) XTE J1859+226 (1999-2000) GX339-4 (3 outbursts) 4U1543-47 (2002) H1743-322 (2003) • Power law : thermal (disk) coupling  YES!

  20. Distributions in Photon Index Hard SPL Thermal

  21. Distributions in Temperature Hard ThermalSPL

  22. Distributions in Disk Fraction (2-20 keV) Hard SPLThermal

  23. “Unified Model for Jets in BH Binaries” Fender, Belloni, & Gallo 2004 Remillard 2005

  24. Coupling: power-law and thermal components GRO J1655-40 XTE J1859+226 XTE J1550-564 Hard: cannot see diskThermal : yesSPL : no

  25. Conclusions • Observationsof BH X-ray states : need 3 models ! • Thermal state: weakly magnetized disk (GR/MCD + MRI) seems quite satisfactory • Hard state: key topics: hot flow : jet coupling ; spin? • SPL state : PL:disk flux uncoupled; non-thermal corona (to MeV?); LFQPOs ; HFQPOs ; kinship to hard state is a key question

  26. GR in SPL State: High Frequency QPOs

  27. High Frequency QPOs source HFQPO n (Hz) GRO J1655-40 300, 450 XTE J1550-564 184, 276 GRS 1915+105 41, 67, 113, 168 XTE J1859+226 190 4U1630-472 184 + broad features (Klein-Wolt et al. 2003) XTE J1650-500 250 H1743-322 166, 242 ------- ISCO for 10 Mo BH: nf = 220 Hz (a* = 0.0)  728 Hz (a* = 0.9) Condensations at preferred radii  QPOs (Schnittman & Bertschinger 2004)

  28. High Frequency QPOs source HFQPO n (Hz) GRO J1655-40 300, 450 XTE J1550-564 184, 276 GRS 1915+105 41, 67, 113, 168 XTE J1859+226 190 4U1630-472 184 XTE J1650-500 250 H1743-322 165, 241 ------- 4 HFQPO pairs with frequencies in 3:2 ratio

  29. HFQPOs Mechanisms • Diskoseismology (Wagoner 1999 ; Kato 2001)  obs. frequencies require nonlinear modes? • Resonance in Inner Disk (Abramowicz & Kluzniak 2001). • Parametric Resonance (coupling in GR frequencies for {r, q}Abramowicz et al. 2004 ; Kluzniak et al. 2004; Lee et al. 2005) • Resonance with Global Disk Warp (S. Kato 2004) • MHD Simulations and HFQPOs (Y. Kato 2005) • Torus Models (Rezzolla et al. 2003; Fragile et al. 2005) • GR ray tracing of accretion torus (Bursa et al.) • Other Models (disk magnetosphere effects: Li & Narayan 2004 ; Alfven waves: Zhang et al. 2004)

  30. HFQPO Frequencies vs. BH Mass GROJ1655, XTEJ1550, and GRS1915+105 nqpo at 2no: no = 931 Hz / Mx • Same QPO mechanism and similar value of a* • Compare subclasses while model efforts continue

  31. LFQPO Subtypes XTEJ1550-564 Wijnands et al. 1999 Cui et al. 1999 Remillard et al. 2002 Rodriguez et al. 2004 Casella et al. 2005 QPOs across states Jet  INT  SPL ?? diff. mechanism ?? evolution in magnetic instability Type: A B C Phase Lag: soft hard near zero n0 (Hz): ~8 ~6 0.1 – 15 a (rms %) few few 5 – 20 Q : 2 – 3 ~10 ~10 State: SPL SPL Hard/Int. HFQPO coupling yes, 3noyes, 2no no HFQPOs

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