Plasma S tates in Accretion & Outflows

from Black Holesand Neutron S tars

Max CamenzindZAH/LS W KönigstuhlXLA @ Paris 2008

MHD at ZAH/LSW Heidelberg• JETSET RTN: YSOs• MHD Jet-Instabilities

• Cooling Jets• BHs & NS:• MHD-Accretion, Jet Production & Propagation in Cluster Medium

• Implicit GRMHD (A. Hujeirat)

PoloidalCurrentFlow~ RBφ

Shocks,MHDInstabilities,Entrained ?

Stationarymodelsdo notexplaininternalstructuresTest for stabilitiy t-dep MHD

Cooled downMagnetized ?

Magnetized ?

10,0

00 –

100

,000

AU

Molecular cloud core

Cygnus AThermal

330 MHz

---------- 70 kpc ---------

Credits: Chandra/VLA

Bipolar Outflows in Galaxies

Hot Cluster GasDensity Profile

Bow ShockWeak Shock M ~ 1.2

ShockedClusterGas

Radio Lobes:Filled with hot ions+ relativistic electrons,Synchrotronand IC Emission

Hot Spot:ParticleAcceleration

Kpc-ScaleBipolar Jets

V. Gaibler,M. Krause &M. Camenzind

Volker Gaibler LSW 2008 - Propagation in Cluster Core / different dens contrast

Density

Temperature[ 1010 K ]

5 x 107 K

Dens = 0.01 / cm³η = 0.1

η = 0.01

η = 0.001 η = 0.0001

S tellar

GRBs

Galaxies

Gravitations-Wellen

TeV-BHs atLHC CERN !? ?

GRBs

GravitationalWaves LIGO

Black Holes inAstrophys ics

GRBs

Overview: XPlasmas around BHs• Most extreme plasma which can be observed

occur near Black Holes and Neutron Stars via observations in X-rays and soft gammas.

• What can we observe about Black Holes? masses M, spin a (?), accretion rates, spectral states and and turbulence in accretion disks (RXTE, …).

• What we don‘t know: interpretation - these are all more or less phenomenological models.

• Why is Turbulence the key for understanding ? study µQuasar accretion.

• Connection Turbulence – Jet Production

„BHs have 2 Parameters“

Camenzind 2006

Why are µQuasars interesting ?• Stellar BH sources in Binaries, ~ 40 known• They have either a high-mass companion

(O, B) HMXB (Cyg X-1, LMC X-3, M33 X-7) probably wind accretion

• or a low-mass companion (K or M dwarf) LMXB (most of the sources)

Time-scales are much shorter than for Quasars full accretion cycles can be observed over the years (RXTE since ´96) for a Quasar ~ Mios of years !!!

-6.8 +/- 0.4K5 V0.171 dXTEJ1118+480

-4 +/- 1M2 V0.212 dGROJ0422+32

-5.2 +/- 0.6K7 V0.283 dGRS 1009-45

--K4 V0.321 dXTEJ1650-500

-11 +/- 2K4 V0.325 dA 0620-00

-7.5 +/- 0.3K3 V0.345 dGS 2000+25

---0.382 dXTE 1859+226

-7.0 +/- 0.6K3 V0.433 dGS 1124-168

-6 +/- 2K3 V0.520 dH 1705-250

0.75-0.859.4 +/- 1.0A2 V1.125 d4U 1543-47

-9.6 +/- 1.2G8 IV1.542 dXTEJ1550-564

0.93+/-0.04 (Suz)-B0 V1.754 dGX 339-4

-7.1 +/- 0.3B9 III2.816 dXTEJ1819-254

0.6 – 0.86.3 +/- 0.3F3 IV2.620 dGRO J1655-40

0.2 – 0.47.6 +/- 1.2B3 V1.704 dLMC X-3

0.77+/-0.0515,6 +/- 1.4O7 III3.45 dM33 X-7

-> 4O7 III4.229 dLMC X-1

0.4 – 0.68 +/- 2O9.7ab5.600 dCyg X-1

-12 +/- 2K0 IV6.470 dV404 Cyg

0.9 – 1.014 +/- 4K/M III33.5 dGRS1915+105

S pin aMass of BHDonor S tarBin. PeriodObject

Rem

illar

d &

McC

linto

ck 2

006;

Cam

enzi

nd 2

007

Hig

h M

ass

Obj

ects

Mes

sier

33

X-7

W

ind

Acc

retio

n

Blue Supergiant70 solar masses

Messier 33 X-7Period: 3,45 d2007 identified15,7 sol mass within 1 Mio yrs to a double BH system

Orosz et al.: Nature 2007

Black Holes with S upergiantsRXTE Light Curves 1996 - 2006

LH

HS

Disc Cooling

• Standard accretion disc: blackbody-like spectrum of temperature less than ~1 keV, with a hard extension towards MeV

• Spectrum at higher energies: fraction of accretion power is dissipated in a hot, optically thin medium

• Emission mechanism: inverse Compton scattering of disc photons off hot electrons with kTe ~ 30 keV.

Spectral states of Cyg X-1disc

ComptonisationHigh Soft state

LowHard state

Black Hole S pectral S tates Cyg X-1 shows two major spectral

continuum components: (i) thermal component from a standard

accretion disk, kBT ~ 0.5 keV (ii) power-law, formed by the soft

photons upscattered in a hot plasma (probably ADAF, Comptonisation).

In the low state, this power-law dominates (LH), in high state soft (HS).

Typically a K Star~ 0,7 Solar Massesfills Roche-Lobe Transient Source

Black Hole: 4 – 7 Solar Masses

TurbulentAccretionDisk

LMXB Binary System Time-Dependent Mass Exchange X-Ray Radiation Nova-like Outbursts

Inte

gral

Spe

ctra

G

X 3

39-4

in O

utbu

rst

Highsoft states Low

Hard states

dos Santos et al. 2008

S caling toAccretion

S tatesof AGN

-Hysteresis

inIntensity

and Hardnessfor

accretion events

LEd

0.05 LEd

FSQuasars, FR IIs

BL

Lacs

, FR

Is

QSO

s, S

ys N

LS1

Koerding et al. 2006; …. ; Camenzind 2008

The Truncation Paradigm

Esin et al. 1997;Müller & Camenzind 2005

ComptonizationCloud

Comptonized HFlux Power Density Spectra

Truncated Disk in Neutron Stars

11 km 15 km

Hot DiskBoundary Layer

ISCO12.6 km

Camenzind 2008

Scaling of Accretion

Mass only responsible for scaling of length scales and time scales.Typical length ~ 50 km for stellar BHs Typical length ~ m for „Jupiter-like BHs“ All physical quantities scale with mass M: density, pressure, temperature & B-fields: ρ ~ 0.01 g/cm³ (cooled phase); kBT ~ 10 keV (cooled !), ~ 100 MeV (unc); B ~ 100 kGauss β ~ 1000 VA ~ 100 km/s ~ cS

Plasma Parameters forS tandard Disks in Microquasars

~ similar to solar conv zone & Lab ; Pm = 1

Henri & Balbus 2007

Observing the Kerr Metric, its Spots and Turbulence

B. Zink, A. Kaminski, F. Neuschäfer [LSW 2005 – 2008]

Accretion is Turbulent – Cyg X-2

Lev Titarchuk et al. 2007

Orbital period

Outer Disk / SAD Low Frequency Noise

Inner Disk / ADAF~ Optically thin BL High Freq Noise

HS S tate Cyg X-1 PDS Low Frequency Noise

Lev Titarchuk et al. 2007

Break frequencyPbin = 5.6 days

~ 1/f Noise Random walk of vortices ?

Hig

h Fr

eq N

oise

in

Cyg

X-1

Lev Titarchuk et al. 2007

Break Frequency

LF QPO

White Noise

Kep

leria

nat

ISC

O

LF Noise

Characteristic FrequenciesKeplerian Freqs are Higher !

For a 10solar massµQuasar:Kepelerianfrequency atISCO ~230 – 1591 HzThese arethe highestFrequenciesLowFrequencies ~Viscous effects not accessible in simulations !!!

10 solar mass µQuasar Scale with Mass

Turbulence and PDS

• Mass accretion onto BHs & NSs is a turbulent process. Turbulence is visible in the optically thick emission from disks as LF noise.

• It becomes, however, visible in the optically thin Comptonized hard X-rays.

Method: measure power density spectra (PDS) for hard X-ray emission.

• PDS are different in LH state vs HS state.• Characteristic frequencies are much below

typical Keplerian frequencies in the inner part ~ 250 – 1200 Hz for 10 solar mass BH

Disk MRI Turbulence

• Dispersion relation: ω4 + ( ) ω2 + ( ) = 0(perturbations in velocity and magnetic field are α e-iωt)

• This implies • Instability requirement: (k vA)2 < - dΩ2 / d ln(r)

(k = wavenumber, vA = poloidal Alfven speed, Ω = angular velocity)• For a Keplerian disk:

• Instability when (k vA)2 < 3Ω2

• Wavelength with fastest growth occurs when (k vA)2 = (15/16) Ω2

• This wavelength grows at rate ω = (3/4) Ω

B

r

z

δBφ

-δvφi δvr

-i δBr

tension

shear induc

tion

centrifugal

RadGRMHD

• FLASH (NNetwork)• AMRVAC (SR, Kepp)• PLUTO (SR, Torino)• ATHENA (Cart, Stone)• AstroBear (A.Frank)• ENZOmhd (Cosmo)• NIRVANA3 (Ziegler)• Pencil (Brandenburg)

• Shapiro et al. (GR)• WhiskyMHD (GR)• Valencia-Code• Hawley-DeVilliers

(Non-Cons, Kerr)• HARMS (2D, K)• Komissarov (K)• RHAISHIN (K, Nish)• GR-I-MHD (HD, Huj)

MinkowskiConservativeMHD

ModernGRMHD

Modern RadGMRHD

Energy-momentum tensor:

Metric (3+1 split):

BField in Plasma System

Radiation Energy-Momentum

Black Hole MRI Simulations

Torus hydro stable; Suitable initial configuration;+ Weak magnetic field (zero net-flux) Plasma beta ~ 100 - 1000

3D MRI Simulations – Toroidal Field

Roman Gold LSW 2008

• Initial torus configuration

• Pseudo-Newtonian

• SRelativistic + conservative PLUTO code

• Torus ~ 30 rg

1500 lcts• ~ 26 ISCO

rotations• 1 lct = rg/c∀ νlct = 20000 Hz

4400 lctsRoman Gold LSW 2008

Spiral Waves in MRI-Disks

ISCO

Dip Field Topology – Zero Net Flux

Beckwith & Hawley 2008

900 lcts

Turbulence depends on

Magnetic Configuration Quadrupole topology:

– 2 loops located on opposite sides of equatorial plane

– Opposite polarities

– Everything else in torus is the same as dipole case

Beckwith, Hawley & K. 2008

Results from Toroidal MRI• Toroidal field cannot be amplified by shear. Non-axisymmetric MRI is operating• on azimuthal wavelength λφ ~ VA/Ω short wavelength turbulence

(rapidly alternating poloidal fields). no large-scale coherent field

generated. plasma beta > 1 ! disk near equatorial plane pressure

dominated. No jets produced !

TOKAMAK Turbulence

Magneto-Rotational Turbulence in Taylor-Couette Flows

Transports Angular Momentum

θu′

⇒ Spirals of high and low speed or angular momentum

Cattaneo et al.

Summary• The (relativistic) MHD model is a fruitful

ansatz for understanding plasma processes near compact objects and in the jets on large scales (> kpc).

• Plasma properties near BHs can easily be scaled to Lab-scales (Jupiter-like BHs).

• Accretion can be probed with X-ray novae cooling processes are not negligible.

• RadGRMHD will be the ultimate theory.

Summary - 2• MHD models have now reached a quite

sophisticated numerical level .• Large-scale MHD jet simulations only

give the distribution of thermal plasma and magnetic fields.

• Marriage of MHD with local particle acceleration models handle on observed synchrotron emission.