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Accretion and Ejection in Nearby Low Luminosity AGNs

Accretion and Ejection in Nearby Low Luminosity AGNs. Sgr A* --- LLAGNs --- QSOs Qing-wen Wu Korea Astronomy and Space Science Institute Collaborators: Feng Yuan, Xin-Wu Cao, Min-Feng Gu (Shanghai Obs.) Ya-Di Xu (SJTU). Outline. 1. Introduction

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Accretion and Ejection in Nearby Low Luminosity AGNs

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  1. Accretion and Ejection in Nearby Low Luminosity AGNs Sgr A* --- LLAGNs --- QSOs Qing-wen Wu Korea Astronomy and Space Science Institute Collaborators: Feng Yuan, Xin-Wu Cao, Min-Feng Gu (Shanghai Obs.) Ya-Di Xu (SJTU)

  2. Outline 1. Introduction 2. X-ray Spectral Evolution in AGNs/XRBs: Evidence for Different Accretion Mode? 3. Origin of X-ray Emission in FR Is: ADAF or Jet? 4. Accretion Power and Jet Power Extracted from ADAF, and Applications 5. Conclusion

  3. 1.1 Properties of LLAGNs • AGN: SMBHs + Accretion disk + BLR + Torus + NLR + Jet (for RL AGNs) Type 0/I/II; Radio Quiet [QSOs, Seyferts etc.]+ Radio Loud [FR I/II, FSRQs/BL Lacs etc]; LLAGNs=L-Seyfert; LINER;FR Is, BL Lacs etc. • Top 10 properties of LLAGNs (Ho 2003, 2008) 1. Very common (>~40% of nearby galaxies) 2. Low ionization (>~2/3) 3. Low accretion power (Lbol<~1044 erg/s) 4. Sub-Eddington (Lbol/L Edd<~10-2) 5. Radiatively inefficient 6. No big blue bump 7. Big red bump 8. Radio loud 9. No broad Fe K_alpha line 10. Some show broad double-peaked emission lines Ho 2008

  4. 1.2 Accretion-Ejection in AGNs and XRBs High/soft state Luminous AGNs (1) Standard accretion disk (Shakura-Sunyaev1973 ) Optically thick, Geometrically thin (H/R<<1), Te=Ti~105-7 K 0.01<~mdot<~1 ---Luminous AGNs (QSO, Seyfert etc.),high/soft XRBs (2) Advection Dominated Accretion Flows (ADAF, Narayan & Yi 1994) Optically thin, Geometrically thick (H/R~1),, Te~109 K, Ti~1011 K, advection mdot<~0.01 ----Low luminosity AGNs, low/hard state XRBs Low/hard state Low luminosity AGNs

  5. 2. X-ray Spectral Evolution: Different Accretion mode? AGNs XRBs Gu & Cao 2009, MNRAS Wu & Gu 2008, ApJ • Anti-correlation: consistent with ADAF, increase mdot  density increase  optical depth increase  harder X-ray spectrum (Esin et al. 1997) • Positive-correlation: consistent with SSD + corona (Cao 2009) • Cross-point corresponding to ADAF-SSD transition? QSO LLAGNs

  6. 3. Origin of nuclear X-ray from FR Is FR I • FR I: low power radio galaxy with large viewing angles. • Radio is from jet for FR Is and other LLAGNs (Wu & Cao 2005,…) • Origin of X-ray (FR Is and other LLAGNs): Jet dominated? (Falcke et al. 2004; Markoff et al. 2004,…) ADAF dominated? (Merloni et al. 2003) Or both? (Yuan et al. 2005; Wu et al. 2007) • So, we use the coupled ADAF-Jet model (Yuan & Cui 2005) to investigate the problem of X-ray origin in FR Is. • Radio and optical emission of FR Is is come from jet (Constrain jet model). • Then combine jet and ADAF to fit the X-ray spectra.

  7. Fitting results （1） 3C 346 ：i~320 ,v>0.8c （2）B2 0755+37 : i~300 ,v~0.9c （3）3C 31 : i~520 ,v~0.87c （4）3C 317 : i~500 ,v~0.9c （5）B2 0055+30 : i~380,v~0.9c （6）3C 66B : i~450 ,v~0.9c （7）3C 449 : i~82.50 ,v~0.9c （8）3C 272.1 : i~630 ,v~0.9c LX/LE=1.8*10-4 LX/LE=5.2*10-6 LX/LE=4.4*10-6 LX/LE=3.6*10-6 LX/LE=2.4*10-6 LX/LE=1.6*10-6 LX/LE=8.0*10-7 LX/LE=8.3*10-8 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*10-6 Physical reason: LxADAF proportion to m2 LxJet proportion to m · · Wu, Yuan & Cao 2007, ApJ

  8. 4. Accretion power and jet power from ADAF a) BZ process:Energy and angular momentum are extracted from a rotating (B & Z 1977) b) BP process:Extract energy from the accretion disk itself to power the jet/outflow (B & P 1982). c) Accretion/Jet power mdot_tr~0.01 for transition of ADAF/SSD Roughly consistent with that constrained from XRBs (10-4-10-2, Fender et al. 2003; Migliari & Fender 2006). Mbh=108Msun, mdot=0.01, based on globalKerr ADAF. (1) Jet power is not sensitive to the ADAF parameters. (2) Qjetdisk >~ 25 QjetBZ (3) Our Qjetdisk is similar to that of full Kerr metric MHD simulations (Hawley & Krolik 2006). (4) All quantities are evaluated at R=Rms. Jet power dominated for mdot<mdot_c Accretion power dominated for mdot>mdot_c Wu & Cao 2008, ApJ

  9. FR I FR II Xu, Cao & Wu 2009, ApJ Ghisellini & Celloti 2001 Xu, Cao & Wu 2009, ApJ BL Lac FS QSO Jet power extracted from ADAF and FR I/II Dichotomy FR I/ FR II Dichotomy and also BL lacs/FS QSO FR I: low-power/edge-darkened FR II: high-power/edge-brightened Physical reasons? (a) different physical conditions in their ambient medium (Gopal-Krishna et al. 2000) (b) different accretion mode and/or jet physics (e.g., Bicknell 1995) The dividing line of FR I/II and BL Lac/FS QSO is roughly corresponding to jet power extracted from ADAF with mdot~0.01, and BH spin j=0.9-0.99. FR I/ FR II -----ADAF/SSD? BL Lac/FS QSO ------ADAF/SSD? FS QSO BL Lac Wu & Cao 2008, ApJ

  10. 5. Conclusion • Anti-correlation and positive correlation of X-ray spectral evolution in AGNs and XRBs may suggest different accretion mode: ADAF and SSD. • X-ray emission from FR Is (and other LLAGNs) may dominated by ADAF, jet or both, which is depend on Eddington ratios, and critical Lx/LEdd~several*10-6 • Jet power will dominated at low accretion rate, while accretion power will dominated at high accretion rate, the critical value which is depend on BH spin. • FR I/II dichotomy (BL Lac/FS QSO) may caused by the different accretion mode, and BHs spin very fast in these radio galaxies (j=0.9-0.99).

  11. Thanks for your attention!

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