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