Collaborating with A. Pierens, J.M. Hure (Meudon Observatory) C. Matsumoto, K.M. Leighly (Univ. of...
-
Upload
sabina-letitia-ball -
Category
Documents
-
view
220 -
download
0
Transcript of Collaborating with A. Pierens, J.M. Hure (Meudon Observatory) C. Matsumoto, K.M. Leighly (Univ. of...
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?