Collaborating with
A. Pierens, J.M. Hure (Meudon Observatory)
C. Matsumoto, K.M. Leighly (Univ. of Oklahoma, USA)
Radiation Spectra from Super-Eddington Active Galctic Nuclei
Toshihiro KAWAGUCHI (Meudon Observatory, France)
1. Introduction to Super Eddington accretion:
2. Latest disc model 1: Vicinity of Black Hole (< 100 RSch)
3. Latest disc model 2: Outer region (~ 104 RSch)
4. Spectral fit to Narrow Line Seyfert 1 galaxies
5. Summary
Optically Thick, Advection Dominated Flow with M >> LEdd/c2
•Begelman & Meier (1982)– t(accretion) >> t(diffusion)
(M < LEdd/c2)
– t(accretion) << t(diffusion)
“Photon Trapping”
(M >> LEdd/c
2)
•Abramowicz et al. (1988)
– L < several x LEdd
– Flow shines
even inside 3 x RSch
~
~
Radius (RSCH)
1-3. Models of super-Eddington accretion:
(Kawaguchi 2003)
~
2-1. Effects of Comptonization: y*
⇒ Comptonization in slim d
isks [Mdot/(LEdd/c2) >> 1] is muc
h more important than that
in standard disks
[Mdot/(LEdd/c2) < 10].~
Spectral distortion due to electron scattering
M / (LEdd/c2)
y* = 1
M_BH=32Msun
M_BH = 10^6.5 M_sun, = 0.1
2-1. Comptonization; why do we get so large y*?
_es’ ~ 10
y* = (4kT/mec2)
(_es’)2
Scattering +
absorption
z
Sub-Eddington (M=LEdd/c2) SuperEdd(M=1000LEdd/c2)
Larger density, lower Tem. Lower density, higher Tem.
es/abs ~ 100 es/abs ~ 10^5
_es’ ~ 300
2-3. Spectra with several effects
M_BH = 10^6.5 M_sun, Mdot/(LEdd/c2) = 1000, = 0.1
No Advection: [heating = rad. Cooling]
R_in = 3 R_Sch, L = 63LEdd
Soft X-ray
With Advection [still
In = Bn(Teff);
Mineshige et al. 2000]
L ~ 5.1 LEdd
+ Gravitational Redshift
+ Transverse Doppler S
hift (Innermost region b
ecomes faint):
L ~ 2.6 LEdd
2-3. Spectra with several effectsM /(LEdd/c2) =
1000With Advection
+ Relativistic CorrectionNo Advection
+ Opacity of Electron Scatteri
ng
(ie, Modified blackbody)
+ Comptonization
Soft X-ray
Gradual Slopes in
Soft X-ray
Comparison with observations
T_color / T_eff ~ 3.4
(Kawaguchi 2003)
=
If > (sg) → Self-gravity onsets
Kawaguchi (2003)
Mdot = 1000 LEdd/c2
3-1. Latest disc model - 2 : Outer region-- A problem in the current disc model --
Den
sity
Radius
104 RSch
Computations invalid
3-3. Outer edge of non self-gravitating disk
Mdot
RSG
Sub-EddingtonSupper-Eddingto
n
= (sg) [ = Ω2 / (4 G) ] at RSG
(Kawaguchi, Pierens, Hure 2003)
SG
SG: corresponding to
emission from RSG
1-2 m
Torus
Non self-gravitating disc
“Spectral Window to Observe Self-Gravity”
4-1. Spectral fit to Ton S 180 & PG1448:
- Nearby Narrow-Line Seyfert 1 galaxies at z~0.065
- highest-(Mdot/MdotEdd) objects (Mdot > 500LEdd/c2)
L
(B
-ban
d)
MBH Kawaguchi (2003)Low-MBH
High-M/MEdd
4-2. Ton S 180: SED
- Data from Turner ++ 02 (Vaughan ++02), and IRAS
L
4-4. Ton S 180: Inner Slim Disk
- (MBH, Mdot, ) are determined by the least square fit
→ 106.8 MSun, 1000 LEdd/c2, 0.002
→ RSG = 3000 RSch
R<RSG
4-5. Ton S 180: Dusty Torus
- Power-Law with a cut-off (Tmax = 1500 K, here)
- Inner most radius is about 3 x 105 RSch (= 100 RSG)
R>100RSG
R<RSG
~
4-8. Ton S 180: Self-Gravitating Disk-1
- Assumptions; R, R ( 1)
- Inner boundary conditions; (RSG) and H(RSG)
- Outer most radius is chosen to be 10 RSG
R>100RSG
R<RSG
(Kawaguchi, Pierens, Hure 2003)
~ RSG-10RSG
4-9. Ton S 180: Self-Gravitating Disk-2 in self-gravitating disks
SPH simulation by Lodato & Rice (2003)
(grav. Instabilites) > (viscous), if disc mass is large.
Radius Radius Radius
Mdisc=0.05MBH 0.1MBH 0.25MBH
4-10. Ton S 180: Self-Gravitating Disk-3
Three solutions below fit the observed spectrum equally.
out ( ~ r^) Mdisc
0.002 0.3 0.4MBH
(i.e. constant )
0.02 -0.6 1.4MBH
0.1 -1.5 7MBH
radiusRsg
out
Further understanding of grav is necessary
4-18. Broad-band fit to PG1448 (preliminary)
(Kawaguchi, et al. in prep.)
TonS180
4-18. Broad-band fit to PG1448 (preliminary)
(Kawaguchi, et al. in prep.)
TonS180PG1448, NH(Gal)
corrected
Soft X-ray gradually deviate from hard X-ray power-law component.
4-18. Broad-band fit to PG1448 (preliminary)
(Kawaguchi, et al. in prep.)
-TonS180-PG1448, NH(Gal)
corrected-NH(Gal +
intrinsicmax)
corrected
no strong OI edge (~0.5keV)
4-18. Broad-band fit to PG1448 (preliminary)
(Kawaguchi, et al. in prep.)
-TonS180-PG1448, NH(Gal)
corrected-NH(Gal +
intrinsicmax)
corrected
-MBH ~
10^6.2 Msun,
Mdot ~ 1400 LEdd/c
2
~ 0.002
6. Summary-1/2
•Disk model for super-Eddington accretion disk is improved:
- Vicinity of black hole
* Relativistic correction & Electron Scattering
- Outer, self-gravitating part
* Non self-gravitating disc (~0.001 pc) radiates UV-X-ray
* SG part (~0.01 pc) emits optical
(SG has been studied by maser spots at pc-scale.)
* Disc mass is comparable to/larger than BH mass.
6. Summary-2/2
Mid-IR to X-ray SED of the highest-(Mdot/MdotEdd) objects:
- fitted well by inner non SG disk + outer SG disk + torus
Issues to be solved theoretically;
* Small (~ 0.001) is inferred in the inner,
advection dominated (i.e. photon trapped) part.
=> Radiative MHD simulations will answer.
* Efficient transfer/heating by gravitational instabilities
at outer SG part?