10/28/2010 SEAL@GSFC - PowerPoint Presentation

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MHD Accretion-Disk Winds as

AGN X-ray Absorbers ~ Seyfert galaxies to quasars ~

Demos Kazanas Keigo Fukumura Astrophysics Science Division Code 663, NASA/GSFCEhud Behar (Technion, Israel)John Contopoulos (Academy of Athens, Greece)

ApJ (2010), 715, 636 ApJ (2010), 723, L228

Credit: NASA/CXCSlide2

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Demos Kazanas (NASA/GSFC)

Collaborators

Ehud Behar (Technion, Israel)Ioannis Contopoulos (Academy of Athens, Greece)J. Garcia (CUA/GSFC)T. Kallman (NASA/GSFC)T. Sakamoto (UMBC/GSFC)C. Shrader (USRA/GSFC)J. Turner (UMBC/GSFC)

Acknowledgement:Slide3

Dust reprocessing, n(r) ~ 1/r (Rowan-Robinson 1995)

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The Scientific Method

It is a capital mistake to theorize before one has the data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts.

Sir Arthur Conan Doyle

It is also a good rule not to put too much confidence in experimental results, until they have been confirmed by theory. Sir Arthur EddingtonFirst you get your facts; then you can distort them at your leisure. Mark Twain

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Some Facts

Absorption features are ubiquitous in the spectra of AGN, GBHC. 50% of all AGN were shown to exhibit UV and X-ray absorption features (Crenshaw, Kraemmer, George 2002). These features have a very broad range of velocities both in UV and X-rays (a few 100’s – 30,000 km/sec in the UV and a few 100’s – >100,000 km/sec in X-rays). X-ray features span a factor of ~105 in ionization parameter indicating the presence of ions ranging from highly ionized (H-He - like Fe) to neutral, all in 1.5 decades in X-ray energy!

These “live” in very different regions of ionization parameter space and likely in different regions of real space. Slide6

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BAL QSO: X-ray Absorptions

X-ray Absorption line (Fe XXV)Spectral index vs. wind velocity

Brandt+(09); Chartas+(09)Chandra/XMM/SuzakuEffect of ionizing spectrum(!?)Fe resonance transitionsX-ray absorber High-velocity outflows: v/c~0.1-0.7 in Fe XXV/XXVISlide7

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Galactic Black Hole (GBH) Binaries

GRO J1655-40: High ionization: log(x[erg cm s-1]) ~ 4.5 - 5.4 Small radii: log (r[cm]) ~ 9.0 - 9.4

High density: log(n[cm-3]) ~ 14Chandra DataMiller+(08) M(BH)~7Msun M(2nd)~2.3MsunNASA/CXC/A.HobartMiller+(06)Slide8

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Outflowing Ionized Absorbers in UV/X-ray  Photoelectric absorption (1) Moderate Outflows ~ various charge state (~100-1,000 km/sec; Nh ~1021-22 cm-2)  Many charge state from X-ray-bright AGNs e.g.

MCG-6-30-15, IRAS 13349+2438 (2) Massive Fast Outflows ~ K-shell resonance (v/c~0.1-0.7; Nh ~1023-24 cm-2)  H/He-like ions from hard-X-ray-weak AGNs e.g. PDS 456, PG 1211+143, APM 08279+5255

Magnetically-Driven Accretion-Disk Winds Slide9

Boroson

2002

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9Our thesis (and hope) is that these diverse data (including those of galactic X-ray sources) can be systematized witha small number of parameters (2) (Elvis 2000)Slide10

Flows (accretion or winds) and their ionization structure are invariant (independent of the mass of gravitating

object;ADAF

) if:

Mass flux is expressed in terms of Eddington mass flux The radius in terms of the Schwarzschild radiusThe velocities are

Keplerian10/28/2010 SEAL@GSFC10Slide11

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Radio-quiet Seyfert AGNs

MCG-6-30-15:(z = 0.007749)PhotoelectricAbsorption: Lines Edges Slow ~ 100 km/sec @ low-x

High ~ 1,900 km/sec @ high-x Integrated NH ~ 5.3 x 1021 cm-2Holczer+(10)(see also Otani+96, Reynolds+97, Sako+03, Miller+08) Chandra

/HETGS

slow

fast

(HETGS)

(RGS)

slow

fast

“Warm Absorber”Slide12

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X-ray-Bright AGNs

QSO:

IRAS 13349+2438: (z = 0.10764) X-ray bright, IR-loud/radio-quiet QSO X-ray obs. with ROSAT, ASCA, Chandra, XMM-Newton Ions with various charge state Fe XVII ~ 300 km/sec

Potential velocity scatter Integrated NH ~ 1.2x1022 cm-2 Chandra dataHolczer+(07)12Slide13

Narrow-Line

Seyferts

(PG QSOs)

10/26/2010 CRESST/UMBC13PG 1211+143Pounds+Reeves(09)

PDS 456Reeves+(09) “Narrow” Hb line < 2,000 km/sec Weak O III/Hb ratio Strong “Soft X-ray Excess” Highly-blueshifted absorption lines

PG 0844+349

Pounds+(03)

(v/c ~

0.2

)

(v/c ~

0.25

)

(v/c ~

0.1

)

Chandra/XMM-Newton dataSlide14

Credit: NASA/CXC/PSU/M.Weiss/G.Chartas

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Broad Absorption Line (BAL) QSOs: APM 08279+5255z = 3.91

~10% of optically-selected QSOs Faint X-ray relative to O/(F)UV continua Broad C IV line ~ 2,000-30,000 km/sec Highly-blueshifted ~ 10,000-30,000 km/sec NRAO/AUI/NSF,STScISlide15

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BAL QSO: UV Apsorptions

APM 08279+5255: (z = 3.91) Lensed QSO (x100) Optically-bright IR-loud, radio-quiet High-velocity outflows v/c~0.04-0.1 in C IV (UV: Keck/HIRES)

Ellison+(99)l7295l7305

UV C IV doublet

Srianand+Petitjean(00)Slide16

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Holczer+(07)

ionizationBehar(09)

AMD(x) = dNH / dlogx ~ (logx)pcolumncolumnionization

Absorption Measure Distribution

(AMD)

(5 AGNs)



presence of nearly equal N

H

over ~4 decades in

x

(p~0.02)

where

x

= L/(n r

2

)

(0.02 < p < 0.29)Slide17

For

radiatively

driven winds one obtains

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Fundamental Questions:

Geometry? Spatial location? Properties? Physical origin?Slide19

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Accretion disks necessarily produce outflows/winds (launched initially with Keplerian rotation) Driven by some acceleration mechanism(s) Local X-rays heat up and photoionize plasma along the way Need to consider mutual interactions between ions &

radiation To AMD through MHD WindsBlandford+Payne(82)Contopoulos+Lovelace(94)Konigl+Kartje(94)Contopoulos(95)Murray+(95;98)Blandford+Begelman(99)Proga+Kallman(04)Everett(05)Schurch+Done(07,08)Sim+(08;10)

& more…Konigl+Kartje(94)

acceleratedSlide20

Magnetically-Driven Outflows

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Magnetohydrodynamics (MHD) (At least) 2 candidates: GRO J1655-40 Miller+(06,08) NGC 4151 Kraemer+(05) Crenshaw+Kraemer(07)Slide21

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MHD Disk-Wind Solutions

Steady-state, axisymmetric MHD solutions (2.5D): 5 “conserved” quantities:

Energy, Ang.Mom., Flux, Ent., Rot.(Contopoulos+Lovelace94)(Prad=0) Look for solutions that the variables separateSlide22

Assume Power Law radial dependence for all variables

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Solve for their angular dependence using the force balance equation in the q-direction (Grad-Safranov equation).This is a wind-type equation that has to pass through the appropriate critical points. Slide23

With the above

scalings

In order that

n(r)~1/r, s = 1 andThe mass flux in the wind increases with distance!! Or rather, most of the accreting gas “peels-off” to allow only a small fraction to accrete onto the black hole (Blandford & Begelman 1999).There is mounting observational evidence that the mass flux in the wind is much higher than that needed to power the AGN/LMXRB.

Feedback! Edot ~ mdot v2 ~r-1/2 ; Momentum input: Pdot ~ mdot v ~ logr  Equal momentum per decade of radius! (talk by J. Ostriker

) 10/28/2010 SEAL@GSFC

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By expressing BH luminosity in terms of dimensionless variables ( or ) the ionization parameter can now be expressed in the dimensionless variables

For s=1,

x

(r) ~ 1/r ; species “living” in lower x-space should come from larger distances.The radiation seen by gas at larger distances requires radiative transfer thru the wind (see Keigo Fukumura’s talk).

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We seek

“q=1” self-similar wind: B(r,q) ~ B(q)/

r n(r,q) ~ F(q)/r (i.e. equal column per decade in radius) LoS velocity ~ 1/r1/2 (Keplerian profile) x(r,q) ~ G(q)/r (w/o attenuation)Density

LoS column density

Ionization parameter

x = r/rs

(c.f. Ueda+03; Tueller+08)

(Contopoulos+Lovelace94)

MHD Disk-Wind SolutionsSlide26

The density has a very steep

q-

dependence with the polar column being 103 – 10

4 smaller than the equatorial. The wind IS the unification torus (Konigl & Kartje 1994). 10/28/2010 SEAL@GSFC

26MHD Wind Angular Density Profile T. Fischer(yesterdy)e (q-p/2)/0.2Slide27

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Simple Wind Solutions with n~1/r

DensityLaunch site

Assume:M(BH) = 106 Msun, G ~ 2 (single power-law), LX ~ 1042 erg/s, mdot ~ 0.5, rad. eff. ~ 10%, n(in) ~ 1010 cm-3(Fukumura+10a)

PoloidalvelocityToroidal

velocity

[cm

-3

]

(q=1)Slide28

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(Note that different

LoS can see different continua; X-ray and UV absorbers need not be identical)Microlensing technique (e.g. Morgan+08; Chartas+09a)  UV regions > X-ray regions (x ~10)Slide30

Dust reprocessing: For n(r)~1/r, equal energy per decade of radius is absorbed and emitted as dust IR emission at progressively decreasing temperature. This leads to a flat

nuFnu

IR spectrum

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Photoionization with XSTAR (e.g. Kallman+Bautista01)

LoS Radiation Transfer

1D computational

zones

Ionization

Distribution

LoS

Radiation

Source

[cm

-3

]

DensitySlide32

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Modeling AMD with n~1/r

Moderately-ionized: (above Fe XVII)~100-300 km/sec@ low ionizationHighly-ionized:(Fe XXV/XXVI)~1,000-3,000 km/sec@ high ionization Const. AMD

Flat AMD (Model)columnvelocity

ionization

Flat AMD (Data)

Holczer+(07)

(q=1)Slide33

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Modeling Absorption Spectra

Wind optical depth

Line photo-absorption cross-sectionfij = oscillator strength DnD = broadening factor H(a,u) = Voigt function

(e.g. Mihalas78)Slide34

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“torus?”

~1-10 pc

“corona”~AUs

NASA/CXC

Disk Wind

Gallagher(07)

“big blue bump

”

~lt days

[Infrared]

BAL QSO

SED

See;

Elvis+(94)

Richards+(06)

[O/UV]

[X-ray]

a

ox

= 0.384 log (f

2 keV

/ f

2500 Å

)

 tells you X-ray weakness

a

oxSlide35

Conclusions, Tests

All accreting BH have winds with velocities

reaching

v~0.5 c! We do not perceive them because they are highly ionized. While NH and x are scale invariant for MHD flows the invariance is broken by atomic physics and radiative processes: Gas densities scale like ~1/M implying that forbidden lines should not be present in the galactic LMXRB spectra. Low ionization species are also absent in LMXRBs because the size of winds is limited by the presence of the companion. The dust sublimation distance in LMXRBs is generally beyond the edge of the disk

 No Sy2-like IR spectra for galactic sources.10/28/2010 SEAL@GSFC35Slide36

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Apply the model to BAL QSOs by changing only

aOX : The decrease in ionizing X-rays allow for FeXXV very close to the BH  hi FeXXV velocity, absorption of CIV forming photons  CIV forms also at small distances leading to hi CIV velocity (but smaller than that of FeXXV).

mdot = 0.5 kT(in) = 5eV GX = 2 aOX = -2

Injected SED (Fn)Log(density)

Fukumura+(10b)Slide37

AMD

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mdot = 0.5 kT(in) = 5eV GX = 2 aOX = -2

Production of CIV and FeXXV/XXVI Slide38

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Correlations with Outflow Velocity

Velocity Dependence on SED (X-ray)

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X-ray data of APM 08279+5255 from Chartas+(09) Model from Fukumura+(10b)Slide39

Conclusions

(

final)

We have produced an MHD model for ionized AGN outflows with 3 parameters: mdot (dimensionless), inclination angle q, and aOX . However the relation between and

aOX and luminosity 10/28/2010 SEAL@GSFC39

Implies that AGN winds can be described with only two parameters . So there is hope for understanding them!Slide40

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Summary

We propose a simplistic (self-similar) MHD disk-wind model: Key ingredients  mdot (column)

LOS angle (velocity) Fn (SED; G, aOX, MCD…etc.) q (field geometry + density structure)

This model (in part) can account for interesting observables: Observed AMD

(i.e. local column distribution N

H

as a function of

x

)

Observed

wind

kinematics

and outflow

geometry

:

Seyferts



~100-300 km/s (Fe XVII); ~1,000-3,000 km/s (Fe XXV)

BAL QSOs

 ~ 0.04-0.1c (UV C IV); ~ 0.4-0.8c (X-ray Fe XXV)Slide41

END

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*

Acceleration Process(es)1. Compton-heated wind (e.g. Begelman+83, Woods+96) “ Central EUV/X-ray  heating a disk  thermal-wind” Issue  Too large radii…2. Radiatively-driven (line-driven) wind (e.g. Proga+00, Proga+Kallman04) “UV radiation pressure  accelerate plasma” Issues

 Overionization @ smaller radii…  Ionization state freezing out…3. Magnetocentrifugally-driven wind “Large-scale B-field  accelerate plasma” Issue  Unknown field geometry…Slide43

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Issues (Future Work)

Wind Solutions (Plasma Field): (Special) Relativistic wind Radiative pressure (e.g. Proga+00;Everett05;Proga+Kallman04) Radiation (Photon Field):

Realistic SED (particularly for BAL quasars) Different LoS between UV and X-ray (i.e. RUV > RX by x10…) Including scattering/reflection (need 2D radiative transfer) (Ultimate) Goals: Comprehensive understanding of ionized absorbers within a single framework (i.e. disk-wind)

AGNs/Seyferts/BAL/non-BAL QSO with high-velocity outflows (e.g. PG 1115+080, H 1413+117, PDS 456 and more…) Energy budget between radiation and

kinetic energy

…Slide44

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Broad Absorption Line (BAL) QSOs

Became known with ROSAT/ASCA survey Large C IV EW(absorb) ~ 20-50 A ~ 30,000 km/sec ~10% of optically-selected QSOs Faint (soft) X-ray relative to O/UV continua High-velocity/near-relativistic outflows: v/c ~ 0.04 - 0.1 (e.g. UV C IV) v/c ~ 0.1 - 0.8 (e.g. X-ray Fe XXV)

High intrinsic column of ~ 1022 cm-2 (UV) >~ 1023 cm-2 (X-ray)Slide45

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Review on Absorption Features:

Crenshaw, Kraemer & George 2003, ARAA, 41, 117 (Seyferts) Brandt et al. 2009, arXiv:0909.0958 (Bright Quasars)Slide46

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END

Chandra

surveyGallagher+(06)Slide47

Para.

CL94

BP82

B

r

-1

r

-5/4

v

r

-1/2

r

-1/2

r

r

-1

r

-3/2

M_wind

r

1/2

r

1/2

Mdot(mass loss rate) ~ 10

-6

Mo/yr Fo (ai/1AU)

5/2

(M/Mo)

-1/2

(Bo/1G)

2

~ 6x10

19

g/sec Fo (ai/1AU)

5/2

(M/Mo)

-1/2

(Bo/1G)

2

~ 6x10

13-16

g/sec (ai/1AU)

5/2

for M=10

8

Mo, Fo=0.0-0.1, Bo=1-10G

r

~ ai

-1

Fo

(Bo/

vo

)

2

r*

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Ly

a C IV10. Normal galaxies vs. BAL quasars

Mg IIHaHbLya NV

Si IVC IV

broad absorption lines

(P Cygni profiles)

normal

BALSlide49

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Ramirez(08)Slide50

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12. Quasars – SED (UV/X-ray property)

Chandra BAL QSO surveyGallagher+(06)UV-bright, X-ray-faint!

aox = 0.384 log (f2 keV / f2500 Å) tells you X-ray weakness

2 keV2500 Å

Elvis+(94)

Richards+(06)

?Slide52

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Side Notes

MCG 6-30-15 Holczer+10Crenshaw+03

Netzer+(03)X-ray spectrum of NGC 3783Slide53

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fainter in X-rays

228 SDSS Quasars with ROSAT

(Strateva et al. 2005)UV Luminosity vs. aoxbrighter in X-raysDefine:

Daox =

a

ox

-

a

ox

(L

uv

)

log(L

uv

)

(ergs s

-1

Hz

-1

)Slide54

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XMM-Newton

dataChartas+(09)G

~ 1.7 – 2.1 Log(NH) ~ 23-24T(var) ~ 3.3 days (~10 rg)X-raySlide55

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Feb. 2010 @Japan

Face-down view (e.g. ~30deg)  low NH, low v/cOptimal view (e.g. ~50deg)  high N

H, high v/c(ii) Velocity dependence on LoSSlide56

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