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The AGN Torus: A Paradigm Change

The AGN Torus: A Paradigm Change. Moshe Elitzur University of Kentucky. What is the Torus?. Smooth continuation of the BLR. X-ray Obscuration. Dusty clouds absorb both UV/optical and X-rays Dust-free clouds absorb only X-rays. Risaliti, Elvis & Nicastro 02:

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The AGN Torus: A Paradigm Change

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  1. The AGN Torus:A Paradigm Change Moshe Elitzur University of Kentucky

  2. What is the Torus? Smooth continuation of the BLR

  3. X-ray Obscuration • Dusty clouds absorb both UV/optical andX-rays • Dust-free clouds absorb only X-rays Risaliti, Elvis & Nicastro 02: Smooth distribution of dusty and dust-free clouds

  4. Lag Times ― BLR and near-IR Suganuma et al 06 No correlation with M!!! NIR(K-band) Broad Emission Line • Broad-emission line lags for objects that also have infrared lags • Including Hi & Lo ionization lines) (luminosity) (nucleus) BLR is dust bound (Netzer & Laor 93)

  5. BLR/XOR TOR The Dust-Sublimation Transition Rd r < Rd — dust free clouds:Broad Lines Region/ X-ray Obscuration Region r > Rd — dusty clouds:Toroidal Obscuration Region TOR = Torus

  6. 0 The Disk Wind Paradigm Everett & Konigl ‘00 Bottorff+ 97

  7. masers BLR/XOR TOR WA Toroidal Obscuration Region Broad Lines Region/ X-ray Obscuration Region Warm Absorber Grand Unification Theory 0 Emmering, Blandford & Shlosman 92

  8. Clumpy Torus Modeling • N0 = 5 – 10 clouds •  = 30° – 60° • V= 30 – 120 • q = 1 – 2 • Rd = 0.4L½45 pc; Ro ≥ 5 Rd s N  N0 exp(-2/2)/rq Standard ISM dust works fine Nenkova et al ‘02, ‘07

  9. Cloud Properties in TOR Outflow IR modeling: v ~ 30 – 120  NH ~ 1022 – 1023 cm-2 Resistance to tidal shearing: n > 107M●7 /rpc3 cm-3 Rc < 1016 NH,23 rpc3 /M●7 cm Mc < 7·10-3 NH,23 Rc,162 M B ~ 1.5 1km/s n71/2 mG Elitzur & Shlosman 06

  10. TOR Scale Height • Clouds rise and expand • M ~ nR3 = nR×R2  NH  M/R2 • Crossing the TOR — factor ~10 expansion •  ~ 1 km s-1 vK = 208 (M7/rpc)½ km s-1  H ~ r

  11. TOR Mass Outflow Rate Rd L½ v(Rd) vK(Rd)  (M•/Rd)½  (LEdd/L½)½ Torus should disappear at small L/LEdd!

  12. Torus Disappearance at Low Luminosities • Nucleus visible in FR I radio galaxies (Chiaberge+ 99) • … and LINERs too (Maoz+ 05) • LINER 1 & 2 UV colors similar (AV <~ 1) • No torus dust emission in M87 (Whysong & Antonucci 04; Perlman+ 07) • No torus dust emission in FR I and ~ half of FR II (van der Wolk+ 07)

  13. If only TOR is removed, all low-luminosity AGN become type 1 HOWEVER • Both type 1 and type 2 LINERs do exist (Maoz et al 05) • “true” type 2 AGN exist at L < 1042 erg s-1 (Panessa & Bassani 02; Laor 03) THEREFORE BLR must disappear at some lower L

  14. TOR BLR • Wind diminishes — mass outflow directed to jets (?) • Ho ‘02, Sikora et al ‘07: Radio loudness (Lrad/Lopt) varies inversely with Macc! .

  15. Radio-loudness; Sikora+ ‘07 R = Lrad/Lopt = L/LEdd

  16. Wind diminishes — mass outflow directed to jets (?) • Ho ‘02, Sikora et al ‘07: Radio loudness (Lrad/Lopt) varies inversely with Macc! . • Similar effect in X-ray binaries

  17. High Low Full Unification Scheme; both type 1 & 2 Accretion Rate (L/LEdd) Radio Loudness molecular outflow extinguished Torus disappears; type 1 only atomic outflow extinguished BLR disappears; “true” type 2 High Low

  18. TOR Energy Outflow Rate Estimate at the wind base — disk surface Outflow: v ≥ vturb ~ 10 km s-1 Negligible in the energy budget

  19. Final Speculation . • With  ~ 0.1, the required accretion rate is Macc ~ 0.1 L45 M yr-1 • The AGN phase lasts ~ 107 108 yrs • Overall accreted mass ~ 106  107 L45 M Is the whole Seyfert phenomenon the accretion of just a single GMC? Is the QSO feeding source different (mergers)?

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