Radiation Hydrodynamic Simulations ofLine-Driven Disk Winds
for Ultra Fast Outflows

Mariko NOMURA (Tsukuba Univ.)
Collaborators: Ken OHSUGA,
Hiroyuki TAKAHASHI, Tessei YOSHIDA (NAOJ),
Keiichi WADA (Kagoshima Univ.)Absorption Lines & AGN Outflows!
!

Blue-shifted absorption lines are detected in some AGNs.
These absorption lines suggest existence of outflows.

!

Ultra-fast outflow (UFO):!
!

FeXXVI lines in X-ray spectra
outflow speed: ~0.1c-0.3c
detected in ~40% of AGNs

FeXXVcounts s-1 keV-1! suggested by FeXXV and/orTombesi et al. (2011)
46810observed energy (keV)

UFOs may have an important role in the AGN feedback because
the mass outflow rate and energy outflow rate are large.
AGN outflow is one of the main targets of ASTRO-H.

Line-Driven Disk Wind
! This wind is accelerated by absorbing the UV radiation from the disk!
!

through the bound-bound transition (called line force).
This model can reproduce the acceleration and the ionization state.
Line-driven mechanism works even in the sub-Eddington source.

ionization stateof the metals

disk windfully ionizedradiation      　 　 　 UV, X

moderately ionized 　         　  UV 　                   　       　 　 　 　 　 　 　 　 　no radiation

BHaccretion disk 　region A 　     　    region B 　       　region C
X-ray source UV source <100RS   　 　 100~1000RS 　        1000RS<

RS: Schwarzschild radius

The metals are overionizedby the strong X-ray.
The line force cannot work.

X-ray is absorbed in theregion A. The line force
can work in this region.

UV is absorbed in theregion A and B. The lineforce becomes weak.

Schematic picture of the line-driven windPrevious Works!

Radiation Hydrodynamic Simulations!
!

!

Proga et al. (2000), Proga & Kallman (2004)
Calculation for the typical one parameter set

Calculation of the streamlines!
!

Risaliti & Elvis (2010), Nomura et al. (2013)
Calculation of steady structures of the winds in a wide parameter
range
Density~10,000km/s

BH

Accretion disk
Proga & Kallman (2004)

streamline

BH

Accretion disk
Nomura et al. (2013)

Our works! Two-dimensional radiation hydrodynamics!

!
!

simulations of the line-drive disk wind inwide parameter range
Comparison between our results andobservational features of the UFOs
(ionization parameter, velocity, and columndensity).
Spectral synthesis based on the simulation
results
Three-dimensional radiation hydrodynamics
simulations

4/15

Method
Basic equations [polar coodinate (r, θ, φ)](1) Mass conservationt(2) Equation of motion(3) Energy equationt+

Radiation force
including the line force· ( v) = 0( vr )
+t
( v )
+t

· ( v v) =( v )+t· ( v v) =1 2v +e2+· ( vr v) =·vv2pv2+++ gr + frad, rrrrv21 pvr v++cot + g + frad,rrrv vrv v+cotrr

1 2pv +e+2

= v·g+ L

Radiative heating/cooling

Radiation force including the line force Force multiplier: function of density,
e FUV
radf
=+c
Radiation force due
to electron scattering

e FUV
Mc

Line force

ionization parameter ξ , and velocity gradient(Stevens & Kallman 1990)=3

ionization parameter:

FX: X-ray flux
n: number density

dependenceξdensity
velocitygradient4 FX=nM

Method
Basic equations [polar coodinate (r, θ, φ)](1) Mass conservation

t+z· ( v) = 0v2( vr )
pv2+ · ( vr v) =+++ gr + frad, rBlack holertrr
X-ray source:v2( v ) central point source
1 pvv
r+ · ( v v) =+ Simulation+ box
cot + g + frad,trrr(2) Equation of motion( v )+t(3) Energy equation

Radiation force
including the line forcet

1 2v +e2+v vrv v+cotrr· ( v v) =30RS·v

1500RSr

1 2
pv +e+= v·g+ L2UV source: standard disk

Radiative
The radiation is divided into twocolors, X heating/cooling& UV.
Radiation source is located outside the simulation box.

Radiation force including the line force Force multiplier: function of density,e FUV
radf=+c
Radiation force due
to electron scattering

e FUV
Mc

Line force

ionization parameter ξ , and velocity gradient(Stevens & Kallman 1990)=3

ionization parameter:

FX: X-ray flux
n: number density

dependenceξdensity
velocity
gradient

4 FX
=nM

ResultsDensity

Disk wind is launchedby the line force.

vr0.1c

3000RS

Accretion disk
BH

MBH = 108 M ,= 0.5

Nomura et al. submitted
7/15

Comparison with the observations of UFO
We compare the outflow velocity, ionization parameter, and column
density with those of UFO.
Conditions for detecting the UFO: About the matter with 2.5 <logξ< 5.5,
(1) outward velocity exceeds 104km/s,(2) column density is larger than 1022 cm-2.

ionization parameter

UFO! UFO features are reproduced when the wind is observed from ~70°.
! UFO probability: UFO /420%

Dependence on Eddington ratio & BH mass

Eddington ratio of UV luminosity (LUV/LEdd)

MBH = 106 M=Black hole mass
MBH = 108 M

MBH = 109 M

UFO probability:27%

0 . 9728%~1.5×109 km

20%~1.5×1011 km

13%~1.5×1012 km

= 0.5

17%
0.1wide parameter range, the disk wind is launched and UFO!= In!

probability is ~15-30%.
The disk wind does not appear when ε=0.01.

Spectral synthesis
Absorption line profile will be resolved by ASTRO-H.
The comparison between the simulations and X-ray observation isnecessary to interpret the absorption line profile and to investigate
whether the line driven disk wind reproduces the absorption lines.

Observations

Simulations
counts s-1 keV-1!
!

Tombesi et al. (2011)4 　 6 　 　 　8observed energy (keV) 　 　 　 　10Spectral synthesis based on the simulation is important.

Method!

We calculate the transmitted spectra through the wind with using
CLOUDY, which is the code for calculating one-dimensionalradiation transfer.

! We use the density and radial
velocity distribution of oursimulations and input the typical
AGN spectra from the center.

! Metal abundance is assumed to besolar abundance.
Observer?
Incident spectra

Transmitted spectraFν/Fν,inputResultsFe XXIV
calculated by Yoshida, T.

E(keV)Fe XXVI absorption line (6.97keV) is blueshifted and appears at around 8keV.

Time variation of absorption features!

What is the origin of the time variability of the absorption
lines ?
PDS456

Gofford et al. (2014)

Absorption lines show time variation within several years.

Time variation of absorption features!

What is the origin of the time variability of the absorption
lines ?

! The ionization state of the outflow changes.
! The outflow has clumpy and non-axisymmetric structure and clouds crossthe line of sight.

Disk windBlack hole and accretion disk

Schematic picture of the non-axisymmetric disk wind©NASAThree-dimensional simulations

log[ (g cm 3 )]Slice at z=80RS plane

BH0-2000

2000

non-axisymmetric structure   0z(RS)4000

rotational  axis  of  accretion  disk  (z-‐‑‒axis)log[ (g cm 3 )]2000

We research non-axisymmetric structure of the disk wind by
three-dimensional simulations.

!

30000accretion disk surfacex(RS)Summary密度! We research the line-driven disk wind by two!
!
!
!

dimensional radiation hydrodynamic simulations.
The funnel-shaped disk wind with high velocity,~0.1c, appears.
The ionization parameter, outflow velocity, and column
density of our results are consistent of the X-ray
observations of UFOs.
The absorption line of FeXXV and/or FeXXVI isreproduced by the line-driven wind.
3D simulation is important to explain the time variationof the absorption lines.