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MIT Workshop on Magnetized Accretion Disks
Supported by:MIT-France ProgramCEA Saclay, FranceMIT Kavli Inst. for Astrophysics & Space ResearchMIT Dept. EE&CSRXTE Project
October 19 & 20, 2006
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?
X-ray States of Black Hole Binaries:
Observations and Physical Models
Ron RemillardMIT Kavli Center for Astrophysics and Space Research
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
Active X-ray States of BH Binaries
Thermal State: thermal spectrum ; L T4 ; 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 ??
Black Hole X-ray Nova
GRO J1655-40
First known outbursts: 1994-95;() 1996-97; 2005
Dynamical black hole binary6.3 (0.5) Mo
Relativistic Jets in 1994~Radio-quiet, 1996-97, 2005
Black Hole X-ray Nova
GRO J1655-40
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
McClintock & Remillard 2006 Compact Stellar X-ray Sources, Ch. 4
Psaltis 2006 Compact Stellar X-ray Sources, Ch. 1
Remillard & McClintock 2006 ARAA, 44, 49
van der Klis 2006 Compact Stellar X-ray Sources, Ch. 2
Zdziarski & Gierlinski 2004 PThPS, 155, 99
X-ray States of BHBs
1. Thermal State: fdisk > 75%; rms < 0.075 ; no QPOs (amax < 0.5%)
inner accretion disk
X-ray States of BHBs
1. Thermal State:
classical disk model: T(r) ~ r-3/4 L(r) ~ r-2
Heat from Accretion Disk ?
T(r) r-p; p ~ 0.7 (Kubota et al 2005) (GR tweak of p=0.75)
modified disk blackbody
GX339-4 Relativistic Fe line
blackbody energetics GR/Keplerian velocities?
Kubota & Done 2004; Gierlinski & Done 2004
e.g. Miller et al. 2004; butsee 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 = Pgas / (B2/8)
Thermal Radiation from a Weakly Magnetized Disk
Alternatives: low 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%; ~ 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%; ~ 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 ?
> 2.4; rms < 0.15 ;
fdisk < 80% + QPOs (or fdisk< 50%)
Energy spectra Power density spectra
1 10 100 .01 .1 1 10 100 Energy (keV) Frequency (Hz)
Neutron stars (atoll type) have thermal and hard states,but they never show strong SPL spectra!
Hard State of BHBsmechanism? 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 amplifymodest outflows of standard sims.
XTEJ1118+480 (low NH)….truncated, cool disk(McClintock et al. 2001)
Steep Power Law
BHB Gamma Ray Bright State(Grove et al. 1998)
blackbody energetics
SPL
|
Physical Models for BHB StatesEnergy spectra Power density spectra
State physical picture
steep power law Disk + ??
thermal
hard state
Energy (keV) Frequency (Hz)
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!
3 X-ray States 3 Different Accretion Systems?
Hard SPL Thermal
Distributions in Photon Index
Hard Thermal SPL
Distributions in Temperature
Hard SPL Thermal
Distributions in Disk Fraction (2-20 keV)
“Unified Model for Jets in BH Binaries”Fender, Belloni, & Gallo 2004 Remillard 2005
GRO J1655-40 XTE J1859+226 XTE J1550-564
Coupling: power-law and thermal components
Hard: cannot see disk Thermal : yes SPL : no
Conclusions Observations of 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
GR in SPL State: High Frequency QPOs
High Frequency QPOs
source HFQPO (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: = 220 Hz (a* = 0.0) 728 Hz (a* = 0.9)
Condensations at preferred radii QPOs (Schnittman & Bertschinger 2004)
High Frequency QPOs
source HFQPO (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
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, }
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)
HFQPO Frequencies vs. BH Mass
GROJ1655, XTEJ1550,
and GRS1915+105
qpo at 2o: o = 931 Hz / Mx
Same QPO mechanism and similar value of a*
Compare subclasses
while model efforts continue
LFQPO Subtypes
Type: A B CPhase Lag: soft hard near zero (Hz): ~8 ~6 0.1 – 15a (rms %) few few 5 – 20 Q : 2 – 3 ~10 ~10State: SPL SPL Hard/Int.
HFQPO coupling yes, 3o yes, 2o no HFQPOs
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
XTEJ1550-564