MIT Workshop on Magnetized Accretion Disks October 19
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
Workshop Handouts & Logistics n Schedule: (4 sessions) n Name Tag n List of Participants n MIT wireless instructions for visitors n Thursday dinner? …stay here after session 2 Legal Seafoods? Cambridge Brewery?
X-ray States of Black Hole Binaries: Observations and Physical Models Ron Remillard MIT Kavli Center for Astrophysics and Space Research
Workshop Motivations n 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 n 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
Active X-ray States of BH Binaries n Thermal State: thermal spectrum ; L a T 4 ; no QPOs Paradigm: Heat from weakly magnetized accretion disk n 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? n Steep Power Law: thermal + SPL + QPOs + HFQPOs ? ? Magnetized Accretion Disk ; Accretion Torus ? ?
Black Hole X-ray Nova GRO J 1655 -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
Black Hole X-ray Nova GRO J 1655 -40 Different X-ray States
Observation Reviews & Global Studies Done & Gierlinski 2003 MNRAS, 342, 1041 Fender 2006 Compact Stellar X-ray Sources, Ch. 9 Fender & Belloni 2004 ARAA, 42, 317 Charles & Coe 2006 Compact Stellar X-ray Sources, Ch. 5 Mc. Clintock & Remillard 2006 Compact Stellar X-ray Sources, Ch. 4 Psaltis 2006 Compact Stellar X-ray Sources, Ch. 1 Remillard & Mc. Clintock 2006 ARAA, 44, 49 van der Klis 2006 Compact Stellar X-ray Sources, Ch. 2 Zdziarski & Gierlinski 2004 PTh. PS, 155, 99
X-ray States of BHBs 1. Thermal State: fdisk > 75%; rms < 0. 075 ; no QPOs inner accretion disk (amax < 0. 5%)
X-ray States of BHBs 1. Thermal State: classical disk model: T(r) ~ r-3/4 L(r) ~ r-2
Heat from Accretion Disk ? modified disk blackbody energetics GR/Keplerian velocities? GX 339 -4 Relativistic Fe line T(r) a r-p; p ~ 0. 7 (Kubota et al 2005) (GR tweak of p=0. 75) Kubota & Done 2004; Gierlinski & Done 2004 e. g. Miller et al. 2004; but see Merloni & Fabian 2003
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 / (B 2/8 p) 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?
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)
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)
States of Black Hole Binaries 3. steep power law compact corona ? G > 2. 4; rms < 0. 15 ; 1 10 100 Energy (ke. V) Energy spectra . 01. 1 1 10 100 fdisk < 80% + QPOs (or fdisk< 50%) Frequency (Hz) Power density spectra Neutron stars (atoll type) have thermal and hard states, but they never show strong SPL spectra!
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. XTEJ 1118+480 (low NH)…. truncated, cool disk (Mc. Clintock et al. 2001)
Steep Power Law BHB Gamma Ray Bright State (Grove et al. 1998) blackbody energetics SPL |
Physical Models for BHB States Energy spectra Power density spectra State steep power law Energy (ke. V) Frequency (Hz) thermal hard state physical picture Disk + ? ?
3 X-ray States 3 Different Accretion Systems? n n Energy spectra YES! Statistical Distributions in key parameters YES! 6 BHBs [417 thermal; 214 hard; 184 SPL; 179 INT (all types)] GRO J 1655 -40 (1996 -97) XTEJ 1550 -564 (4 outbursts) XTE J 1859+226 (1999 -2000) GX 339 -4 (3 outbursts) 4 U 1543 -47 (2002) H 1743 -322 (2003) n Power law : thermal (disk) coupling YES!
Distributions in Photon Index Hard SPL Thermal
Distributions in Temperature Hard Thermal SPL
Distributions in Disk Fraction (2 -20 ke. V) Hard SPL Thermal
“Unified Model for Jets in BH Binaries” Fender, Belloni, & Gallo 2004 Remillard 2005
Coupling: power-law and thermal components GRO J 1655 -40 Hard: cannot see disk XTE J 1859+226 Thermal : yes XTE J 1550 -564 SPL : no
Conclusions n Observations of BH X-ray states : need 3 models ! n Thermal state: weakly magnetized disk (GR/MCD + MRI) seems quite satisfactory n Hard state: key topics: hot flow : jet coupling ; spin? n SPL state : PL: disk flux uncoupled; non-thermal corona (to Me. V? ); LFQPOs ; HFQPOs ; kinship to hard state is a key question
GR in SPL State: High Frequency QPOs
High Frequency QPOs source HFQPO n (Hz) GRO J 1655 -40 300, 450 XTE J 1550 -564 184, 276 GRS 1915+105 41, 67, 113, 168 XTE J 1859+226 190 4 U 1630 -472 184 + broad features (Klein-Wolt et al. 2003) XTE J 1650 -500 250 H 1743 -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)
High Frequency QPOs source HFQPO n (Hz) GRO J 1655 -40 300, 450 XTE J 1550 -564 184, 276 GRS 1915+105 41, 67, 113, 168 XTE J 1859+226 190 4 U 1630 -472 184 XTE J 1650 -500 250 H 1743 -322 ------- 165, 241 4 HFQPO pairs with frequencies in 3: 2 ratio
HFQPOs Mechanisms n Diskoseismology (Wagoner 1999 ; Kato 2001) obs. frequencies require nonlinear modes? n Resonance in Inner Disk (Abramowicz & Kluzniak 2001). q Parametric Resonance (coupling in GR frequencies for {r, q} Abramowicz et al. 2004 ; Kluzniak et al. 2004; Lee et al. 2005) q Resonance with Global Disk Warp (S. Kato 2004) n MHD Simulations and HFQPOs (Y. Kato 2005) n Torus Models (Rezzolla et al. 2003; Fragile et al. 2005) q n GR ray tracing of accretion torus (Bursa et al. ) Other Models (disk magnetosphere effects: Li & Narayan 2004 ; Alfven waves: Zhang et al. 2004)
HFQPO Frequencies vs. BH Mass GROJ 1655, XTEJ 1550, and GRS 1915+105 nqpo at 2 no: no = 931 Hz / Mx Same QPO mechanism and similar value of a* q Compare subclasses while model efforts continue q
LFQPO Subtypes XTEJ 1550 -564 Wijnands et al. 1999 Cui et al. 1999 Remillard et al. 2002 Rodriguez et al. 2004 Casella et al. 2005 Type: Phase Lag: n 0 (Hz): a (rms %) Q: State: A soft ~8 few 2– 3 SPL HFQPO coupling yes, 3 no B hard ~6 few ~10 SPL yes, 2 no C near zero 0. 1 – 15 5 – 20 ~10 Hard/Int. no HFQPOs across states Jet INT SPL ? ? diff. mechanism ? ? evolution in magnetic instability
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