AGN; the answer is blowing in the wind Nick Schurch. Chris Done, Malgorzata Sobolewska & Marek...

AGN; the answer is blowing in the wind

Nick Schurch. Chris Done, Malgorzata

Sobolewska & Marek Gierlinski.

12 years ago, a galaxy far far away…

Turner et al 1993; ROSAT and EXOSAT

AGN are complex

Netzer et al 2003; XMM-Newton


Marshall et al 1993; BBXRT


AGN are complex

Kinkhabwala et al 2004, Matt et al 2004; XMM-Newton


Two problemsDynamical connections.

• How do we fuel the central engine?

• No obvious link between the accretion disk, BLR, NLR, Torus and galaxy.

• Dynamical link MUSTMUST exist.

Spectral components…

• Origin of most components ‘understood’; even if the details are not.

Continuum, accretion disk & neutral reflection, emission and absorption lines, cold and warm absorption etc.

• Origin of the soft X-ray excess is not understood.

• It could be the result of…

A separate spectral component (e.g. tail

of thermal accretion disk emission), but…

Uniform ‘temperature’ indicative of an atomic origin.

Dynamical connections.




Page et al 2004

1H0707-495

Fabian et al 2004

Two problems

Dynamical connections.




cReflected soft X-ray flux Continuum soft X-ray flux.

Ross et al 2005

Spectral components…

• Origin of most components ‘understood’; even if the details are not.

Continuum, accretion disk & neutral reflection, emission and absorption lines, cold and warm absorption etc.

• Origin of the soft X-ray excess is not understood.

• It could be the result of…

Reflection off the accretion disk (atomic,

ionised & realivistically blurred) but…

Difficult to make enough reflected flux to explain the strongest soft excesses.

Two problems

Why is a wind an attractive idea? Physically, a wind provides…

• A simple dynamical link between the regions of the unified AGN.

• A physical origin for the BLR and NLR.

Spectrally, a wind provides…

• Multiple physical locations for ionised emission & absorption.

• A simple explanation of the soft X-ray excess based on atomic physics.

• An origin for the mess of complexity observed in detailed observations.

Why is a wind an attractive idea?Our new picture looks like..

Strongly accelerating wind (~0.1c) …

• High-T, high-, very broad spectral features.

• Difficult to distinguish from genuine continuum emission Soft excess?

Fast wind (~103 km s-1)…

• Broad features, easy to spot BLR.

Slow wind (~102 km s-1)

• Narrow features, easy to spot NLR

Winds are common in nature

etc…

AGN winds on large scalesAGN winds revealed in UV & X-ray observations of the NLR.

• OIII images reveal bi-conical, clumpy structures

• UV emission lines all blueshifted (~500 km s-1).

Chandra & XMM-Newton identified soft X-ray emission co-spatial with the UV ionization cones.

• X-ray emission composed of many spectral lines (Si K, SiXIII OVII, OVIII, NeIX,

NeX Lyman , MgXI).

• X-ray lines all blueshifted (~1000 km s-1).

• Wide range of lines wide range of ionisation states wide range of

densities and/or pressures..

Clumpy, photoionised, outflowing material!

Mrk 78

NGC 4151

NGC 1068

Mrk 3

Modelling winds: X-ray emission & absorptionThe wind is composed of photoionized gas.

Model emission & absorption from the photoionised gas with XSTAR

• Lx=1044 erg s-1, =2.4, =1012 cm-3, NH=1023 cm-2, log()=2.7, Cf=0.5 & Vturb=100 km s-

1.

Include disk refection and galactic absorption…

Unrealistic model

• No outflow velocity fieldParticularly important close

in, where velocity gradient is high!

• R << RWind is thick!

• Constant density gasWind is likely to have very

non-uniform density structure.

R

R

Modelling winds: The velocity field

Gierlinski & Done 2004

The wind will have an outflow velocity that is a function of radius.

• Absorption, and emission, from gas moving at a wide range of velocities.

• Close to the SMBH, gravitational effects will be important.

Simplest approximation is a Gaussian velocity distribution.

Previous work only treated the absorption, but …

• Demonstrated that sufficiently broadened absorption, might reproduce the soft X-ray

excess!

Can this remain the case when we include the emission?

Modelling winds: The velocity field

The wind will have an outflow velocity that is a function of radius.

• Absorption, and emission, from gas moving at a wide range of velocities.

• Close to the SMBH, gravitational effects will be important.

Simplest approximation is a Gaussian velocity distribution.

Previous work only treated the absorption, but …

• Demonstrated that sufficiently broadened absorption, might reproduce the soft X-ray

excess!

Can this remain the case when we include the emission?

Yes… but the lines do fill in some of the absorption.

Vrad=0 – 0.2c, vrad=3000 km s-1

Modelling winds: How strong is the line emission?

The line emission normalization is given by:

Klines = Cf L38 DKpc-2

Cf is the covering fraction of the material.

L38 is the intrinsic source luminosity, between 1-1000 Ryd in units of 1038.

DKpc is the source distance in Kpc.

Given an power-law form input continuum this becomes:

Klines = Cf Dkpc-2 (4Dcm

2) Kpl E-+1dE

Kpl is the normalization of the input power-law

is the power-law photon index

Distance dependence removed!

For a given , the Klines Kpl & Cf.

• Best-fit Klines, c.f. best-fit Kpl, tells us Cf.

Given Cf we can calculate M and Mtotal for the wind.

1 Ryd

103 Ryd

.

cHard to get any other

way!

Consistency Check!

We expect:

• MwindMedd

• Mwind10-(12) M

• Mtotal MBLR 10M

.

. .

.

Can we spot the fast wind?: PG1211+143

Bright (Vmag=14.38), nearby (z=0.089), Quasar (Lx~1044 erg s-1) & NLS1.

Very strong soft excess!

Can we spot the fast wind?: PG1211+143Bright (Vmag=14.38), nearby (z=0.089),

Quasar (Lx~1044 erg s-1) & NLS1.


Complicated X-ray spectrum!

• Thermal comptonization continuum

• Complex absorption system, with multiple warm absorbers (Pounds et al 2003, Chartas et al

2003).

• Ionised accretion disk reflection.

Can we spot the fast wind?: PG1211+143Bright (Vmag=14.38), nearby (z=0.089),

Quasar (Lx~1044 erg s-1) & NLS1.





2003).


We must be careful to get the continuum right! … Aside …… Aside …

Can we spot the fast wind?: PG1211+143 Bright (Vmag=14.38), nearby (z=0.089), Quasar (Lx~1044 erg s-1) & NLS1.





2003).


We must be careful to get the continuum right!

=1.55, no reflection, no complex absorption, Iron K edge, Eedge=7.3 keV.

=1.79, no reflection, complex absorption, Iron XXVI Ly line. Eline=7.02 keV






2003).








2003).



No BeppoSAX data. No Integral data. Poor XTE data. PG1211 is faint > 10keV!

• 2-60 keV = 3! (Guinazzi et al 2000).

We know that NLS1s have steep X-ray continua! (Porquet et al 1999).

Modelling PG1211+143

. .

Thermal Comptonization continuum.• Power-law, 2.4

Accretion disk reflection.• Lx/Ld 0.5

• Min 0.2Medd

• Rinn 20Rs

Two narrow, outflowing, absorption/emission systems.

• log() 2, 3.3

• NH 1022, 1023 cm-2

• Small Cf (<0.1 upper limit)

Diskwind absorption/emission model.

• log() = 2.74

• NH = 1.4x1023 cm-2

• = 0.2c (0.186-0.22)

• Cf 0.4

Modelling PG1211+143Thermal Comptonization continuum.

• Power-law, 2.4

Accretion disk reflection.• Lx/Ld 0.5

• Min 0.2Medd

• Rinn 20Rs

Two narrow, outflowing, absorption/emission systems.

• log() 2, 3.3

• NH 1022, 1023 cm-2

• Small Cf (<0.1 upper limit)

Diskwind absorption/emission model.

• log() = 2.74

• NH = 1.4x1023 cm-2

• = 0.2c (0.186-0.22)

• Cf 0.4

• 2 = 1013/948 d.o.f

.

Even better… Log() = 2.66 3%

NH = 1023 cm-2, = 2, = 0.2

When we vary the ionisation parameter, the spectral shape changes.

• RMS Variability has a VERYVERY characteristic shape!

Do we see this characteristic shape in the observed RMS variability spectra of AGN?

Markowitz, Edelson & Vaughan 2003

Does it really work?

The Good:

• Very good fit to complex data.

• Completely reproduces the soft excess without separate components, or unreasonably strong reflection.

• Smeared wind has a sensible(ish) range of velocities. (c.f. 24000 km s-1 lines & 50000 km s-1 lines – PDS 456)

• Wind , NH also sensible.

• Including emission lines gives sensible Cf.

The Bad:

• How can we reconcile the wind with the other absorption/emission systems?…

• outflowing at a single, slower, velocity & more ionised.

(vout=25000 km s-1 c.f. 60000 km s-1 log()=3.3 c.f. 2.7)

• outflowing at a single, even slower, velocity & less ionised. (vout=12000 km s-1 c.f. 60000 km s-1 log()=2.0 c.f. 2.7)

• Other material represents the wind as it slows down far from the point of acceleration?

• lower ionisation material = condensing phase?

• higher ionisation material = expanding phase?

• Maybe shocks can help us slow the wind down?

The Ugly:

• Mwind1023 M X

• Mwind>Medd>Min X

• Mtotal >>MBLR X

• The current model doesn’t work… but the idea might be right!

• Could be telling us that..

• R ~ R

• constant

• v(R) Gaussian

.

.

..

The next step: Version 1.Run XSTAR on a thick slab.

• Computationally intensive.

Run XSTAR with constant pressure approximation.

• Bug in XSTAR 2.1kn3!

• More computationally intensive than = constant.

Use a more physical velocity field.

• Use equations for velocity along a streamline. – Murray et al 1995

• Weight v(R) with (R).

• Smear using this profile.

Fixed!

The next step: Version 2… with a little help

1, T1, 1, v1

Use info from simulations of a ‘reasonable’ AGN diskwind!

• 108 M black hole.

• M = 2 M yr-1

Chop up simulation and choose l.o.s.

Read out information for each segment

• , T, , vgrad

The next step: Version 2… with a little helpThe next step: Version 2… with a little help

Power-law

1, T1, 1, v1



• M = 2 M yr-1



• , T, , vgrad

• , T, + simple continuum XSTAR


Power-law

1, T1, 1, v1



• M = 2 M yr-1



• , T, , vgrad


• vgrad + XSTAR smearing


2, T2, 2, v2



• M = 2 M yr-1



• , T, , vgrad



• Use this spectrum as the continuum for the next segment the l.o.s

passes through.



• M = 2 M yr-1



• , T, , vgrad




passes through.

• Iterate over total l.o.s.


i, Ti, i, vi



• M = 2 M yr-1



• , T, , vgrad




passes through.

• Iterate over total l.o.s.

Instant disk wind spectrum with self consistent velocity smearing!


i, Ti, i, vi

AGN; the answer is blowing in the wind Nick Schurch. Chris Done, Malgorzata Sobolewska & Marek...

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