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Unification Issues and the AGN TORUS Moshe Elitzur University of Kentucky
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Unification prediction #1 type 2 = type 1 + obscuration namely every type 1 class has a corresponding type 2 QSO2 MUST exist! QSO2 DO exist, even with hidden type 1 engines at z = 0.6 (Zakamska et al 05)
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MRK1239 Rodrìguez-Ardila & Mazzalay ‘06 Prediction #2 — SED: 2 = 1 - AGN
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IR Puzzle #1 r 1.7 pc: T = 320 K Jaffe et al ‘04 VLTI — NGC1068: Poncelet et al ‘06 L bol = 2·10 45 erg s -1 (Mason et al ’06) T(r = 2pc) = 960 K r(T = 320 K) = 26 pc r(T = 226 K) = 57 pc T > 800 K
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T max T min Temperature in Clumpy Medium Nenkova et al 2006
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IR Puzzle #2 Lutz et al ’04 — 6µm vs 2-10 keV x-rays Horst et al ’06 — 12µm vs 2-10 keV x-rays Buchanan et al ’06 — 5-35µm vs radio While its obscuration is highly anisotropic, the torus emission is nearly isotropic: R = IR/radio
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Clumpy Torus – Radial Density Variation Large q (steep radial decline) — Anisotropic obscuration with nearly isotropic emission! N 0 = 5 = 45º V = 60 N N 0 exp(- 2 / 2 )/r q
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Clumpy Torus Modeling N 0 = 5 – 10 clouds = 30° – 60° V = 40 – 120 q = 1 – 2 R s = 0.9L ½ 12 pc; R o > 5 R s Standard ISM dust works fine N N 0 exp(- 2 / 2 )/r q Nenkova et al ‘02; ‘06 s
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Unification Statistics f 2 — fraction of obscured sources = N 2 /(N 1 + N 2 ) Seyferts:f 2 = 70% Schmitt et al 01 f 2 = 50% Hao et al 05 f 2 decreases with luminosity (Simpson 05, Hao et al) — “receding torus” (Lawrence 91) f 2 = sin = 0.5 — 0.7 H/R = tan ~ 0.7 — 1 R RsRs H Basic Premise AGN type determined uniquely by viewing angle
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Clumpy Unification N c ( ) = N 0 exp(- 2 / 2 ) f 2 depends on both and N 0 ! Type 1 sources from “type 2 viewing”, and vice versa Flips between type 1 & 2 (Aretxaga et al 99) f 2 variations may arise from either or N 0 or both AGN type is a viewing- dependent probability!
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Unification and X-rays Evidence for types 1 & 2 orientation-dependence in both X-ray absorption and reprocessing Absorption-corrected type 2 spectra & luminosities are similar to type 1 (Smith & Done 96; Turner et al 97) BUT: The “X-ray torus” probably does not coincide with the “dusty torus”
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Dusty vs X-rays Torus N H (X-ray) ~ 3 — 100 N H (UV) (Maiolino et al 01) From IR modeling N H (torus) <~ 10 24 cm -2, yet at least ~50% of Seyfert 2 are Compton thick (Guainazzi et al 05) Fast X-ray variations — absorbing clouds are dust-free Risaliti, Elvis & Nicastro 02 RXRX RsRs
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Dusty vs X-rays Torus (2) X-ray observations + IR observations and modeling: N H (X-ray) ~ 10 N H (torus) If N clouds ~ 1/r 2 then R X ~ R s /10 (and R s ~ 0.9 L 12 1/2 pc) RXRX RsRs f 2 (X-rays) may be quite different from f 2 (UV/optical)! Sarah Gallagher (Tuesday): Compton thick “x-ray only” absorption in QSO1 (x-ray and UV not consistent with each other)
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Torus Size NGC1068: 2 m imaging – R ~ 1 pc (Weigelt et al 04) 10 m interferometry – R ~ 2 pc (Jaffe et al 04) Cen A: 2 m – R < 0.5 pc (Prieto et al 04) 9 & 18 m – R < 2 pc (Radomski et al 06) Circinus: 2 m – R ~ 1pc (Prieto et al 04) 8 & 18 m – R < 2 pc (Packham et al 05) NGC1097 & NGC5506: 2 m – R < 5 pc (Prieto et al 04) All observations are consistent with R out /R s no larger than ~20-30, and perhaps even only ~5-10
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Dynamic Origin of Vertical Structure Cloud accretion from the galaxy? No need in a compact torus!
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The Torus as a Disk-Wind Region Bottorff et al 97 Everett & Konigl 00
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Cloud Properties in Torus Outflow v ~ 20 – 150 N H ~ 10 22 – 10 23 cm -2 Resistance to tidal shearing: n > 10 7 M ●7 / r pc 3 cm -3 R c < 10 16 N H,23 r pc 3 / M ●7 cm M c < 7·10 -3 N H,23 R c,16 2 M o B ~ 1.5 1km/s n 7 1/2 mG Elitzur & Shlosman 2006
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Unification Scheme
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Grand Unification Scheme masers Emmering, Blandford & Shlosman 92 BLR B road L ines R egion BAL B road A bsorption L ines TORUS T oroidal O bscuration R equired by U nified S chemes
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Outflow and Accretion Torus disappears at L <~ 10 42 erg s -1 !
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Torus Disappearance at Low Luminosities Nucleus visible at L <~ 10 42 erg s -1 radio galaxies (Chiaberge et al 99) and LINERs (Maoz et al 05) No torus dust emission in M87 (Whysong & Antonucci 04; Perlman et al 06) and NGC 1097 (Masson et al 06)
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If only TORUS 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 < 10 42 erg s -1 (Laor 03) THEREFORE BLR must disappear at some lower L
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Torus BLR Wind diminishes — mass outflow directed to jets (?) Ho (2002): Radio loudness varies inversely with M acc ! Similar effect in x-ray binaries.
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Accretion Rate Radio Loudness Full Unification Scheme; both type 1 & 2 molecular outflow extinguished Torus disappears; type 1 only atomic outflow extinguished BLR disappears; “true” type 2 High Low
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Issues for Study It’s all probabilities! X-ray vs UV/optical TORUS properties f 2 decrease at high L — N H or ? TORUS disappearance at low L — N H or v? Low-luminosity end of AGN: IR emission Switch from outflow to jets
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