1. The origin nuclear X-ray emission in the nuclei of radio galaxy-FR Is
Wu Qing-wen
Shanghai Astronomical Observatory, China
Collaborators:
Yuan Feng (SHAO), Cao Xinwu (SHAO)

2. Contents Brief review of FR I/FR II and its central engine Sample
Coupled Accretion-jet model
Spectral fitting results
Conclusion and discussion

3. (1) Active Galactic Nuclei
QSO/Sefert etc
Disk Diminated RQ
AGN RL
FR I/FR II/BL Lac etc
Jet Diminated?
Spectrum: RL RQ
OVV/BL Lac

4. FR I and FR II Radio power and Morphology FRI FRII Hotspot Core Jet
Lobe
Hotspot
Low-power
(FR I)
High-power
(FRII)

5. Optical Jet
M 87
3C 78
3C 31

6. X-ray Jet Chandra can resolve kpc-scale jet in neary RL AGNs
FR Is: X-ray/optical jet is synchrotron in nature (Worrall et al. 2001)
FR IIs: X-ray/optical jet is inverse Compton (Sambrana et al. 2004)

7. The Fanaroff-Riley Dichotomy
Environmental?
Interaction of the jet with ambient medium either causes the jet to decelerate (FRI) or propagate supersonically to large distances (FRII)
Intrinsic?
Properties of the central engine govern large-scale morphology (FRI/FRII)

8. Central engine of RL AGNsLX
Low state
High state
Nature of accretion process:
FR II: High power--SSD?
FR I : Low power –ADAF?
Accretion mode is changed at . .
FR Is are almost entirely
low-excitation ---maybe suggest ADAF
Esin et al. 1997
Accretion flow
mcrit
Jet
mcrit m

9. The multi-wavelength emission in FR Is
The nuclear emission
(X-ray/optical) is dominated by:
The parsec-scale jet? or
Accretion flow
SSD+ corona (High power-FR II?)
ADAF (Low power--FR I?)
Multi-wavelength nuclear emission is correlated.

10. Luminosity-luminosity correlation
Radio emission, optical and soft X-ray core emission
We know that radio core emission is come from the jet!
Optical and X-ray emission: same origin from the jet?
or Disk-jet relation?

11. Evidence for jet dominated optical emission in FR Is
Dual population for LLAGNs and FR Is
LLAGNs: Seyfert/LINERs
Macchetto et al. 2006
Optical core emission show strong polarization Synchrotron Jet emission
Disk dominated
Jet dominated?

12. Origin of the X-ray emission in FR Is
It is an open question:
Jet dominated (Falcke et al. 2004)
luminosity-luminosity relation--Pure jet emission
Accretion dominated (Merloni et al. 2003)
luminosity-luminosity relation---Disk-jet relation
Goal of this work: try to test the X-ray origin in FR Is with coupled accretion-jet model and explore the possible relation between BH accretion and the circumstances near the BH.

13. (2) Sample
The sample include 8 FR Is with estimated black hole mass and Bondi accretion rate, radio(VLA), optical(HST) and X-ray(Chandra) nuclei emission. We also find the other band high resolution emission data, e.g., submillimetre, infrared, UV, from the literature. The X-ray luminosity is Eddington luminosity.

14. (3) Coupled accretion-jet model
Advection dominated accretion flow (ADAF)
Mdot=Mdotout (R/Rout)pw ; beta=Pm/(Pg+Pm)
Jet model: internal shock scenario
shock in the disk part of material transferred into jet
Jet: half open angle ; bulk lorentz factor ;part of the material ( ) is accelerated into power-law distribution with index P; describe the energy density of accelerated electrons and amplified magnetic field.

15. (4) Spectral fitting results
From introduction, we know that the radio and optical core emission is dominated by jet, so we can constraint the jet model with these two band observation and to see the jet contribution at the X-ray band, then combine ADAF model to give the best fittings.

16. ADAF dominated Jet dominated
（1） 3C 346 ：i~320 ,v>0.8c （2）B : i~300 ,v~0.9c
(Cotton et al. 1995) (Bondi et al. 2000)
ADAF dominated Jet dominated

17. ADAF dominated，but jet contribute at a similar level ！
（3）3C 31 : i~520 ,v~0.87c （4）3C 317 : i~500 ,v~0.9c
ADAF dominated，but jet contribute at a similar level ！

18. （5）B2 0055+30 : i~380,v~0.9c （6）3C 66B : i~450 ,v~0.9c
ADAF dominated Jet dominated

19. contribute at similar level)
（7）3C 449 : i~82.50 ,v~0.9c （8）3C : i~630 ,v~0.9c
Jet dominated (or jet and ADAF Jet dominated
contribute at similar level)

20. (5) Discussion (1) X-ray origin in FR Is
High Eddington ratio----ADAF dominated
Intermediate Eddington ratio----ADAF and jet (similar level)
Low Eddington ratio----Jet dominated
The critical Eddington ratio is around Lx/LEdd~several*106

21. · · NGC 4261 (Gliozzi 2003) ；NGC 3998 (Ptak 2004)
This conclusion is similar to other LLAGNs :
ADAF dominated for higher Eddington ratios
NGC 4261 (Gliozzi 2003) ；NGC 3998 (Ptak 2004)
Jet dominated for lower Eddington ratios
NGC 821 (Pellegrini 2007)；IC 1459 (Fabbiano 2003) ；
NGC 4594 (Pellegrini 2003) ；M31 (Garcia 2005)
It is also consistent with Yuan & Cui (2005)’s prediction,
based on “Fundamental plane”.
Physical reason:
LxADAF proportion to m2
LxJet proportion to m

22. (2) BH accretion and its circumstance
Four of five sources (3C 346, 3C 31, 3C449, 3C 317) have BH accretion rates larger than their Bondi accretion rates by factors of 9, 18,112,1.1, respectively.
So, the other fuel supply, e.g. gas released by the stellar population, in the Bondi radius should be important, especially when considering angular momentum, !

23. (3) Accretion power and jet power
Define to describe the efficiency of jet power converted from the accretion power, where jet kinetic luminosity is
BH spin rapidly and most of the accretion power is converted to jet power in these FR Is!

24. (6) Conclusion
The origin of the X-ray in FR Is can come from ADAF, jet or both, which depend on the Lx/LEdd ratio, anyway, the jet contribution at soft X-ray band is important.
Other fuel supply (e.g.,stellar winds) in the Bondi radius should be important for BH accretion.
BH is rapidly spin in FR Is and most of the accretion power is converted into jet.

25. Many thanks for discussions!