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MHD Accretion-Disk Winds and the Blazar Sequence

MHD Accretion-Disk Winds and the Blazar Sequence. Demos Kazanas, Chris Shrader (NASA/GSFC) Keigo Fukumura, Sean Scully (JMU) Markos Georganopoulos (UMBC) (based on work by Fukumura, Kazanas, Contopoulos, Behar. ApJ (2010), 715, 636 ApJ (2010), 723, L228. Credit: NASA/CXC.

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MHD Accretion-Disk Winds and the Blazar Sequence

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  1. MHD Accretion-Disk Winds and the Blazar Sequence Demos Kazanas, Chris Shrader (NASA/GSFC) Keigo Fukumura, Sean Scully (JMU) Markos Georganopoulos (UMBC) (based on work by Fukumura, Kazanas, Contopoulos, Behar • ApJ (2010), 715, 636 • ApJ (2010), 723, L228 Credit: NASA/CXC 10/28/2010 SEAL@GSFC

  2. The Blazar Sequence (Fossati) 10/28/2010 SEAL@GSFC

  3. Does this systematic reflect a broader AGN property or is it limited to blazars? • What is the nature of this correlation and how connects to the general AGN physics? • (Accounts have been proposed by Ghisellini et al suggesting balance between electron acceleration and losses in AGN vicinity). • Our thesis is that it signifies a universal underlying AGN structure hinted to from RQ AGN, in particular from Seyfert X-ray spectroscopy. 10/28/2010 SEAL@GSFC

  4. The general idea is to enlarge, complement, modify this well known cartoon 10/28/2010 SEAL@GSFC

  5. Some Facts of AGN absorbers • Absorption features are ubiquitous in the spectra of AGN, GBHC. • 50% of all AGN were shown to exhibit UV and X-ray absorption features (Crenshaw, Kraemmer, George 2002). • These features have a very broad range of velocities both in UV and X-rays (a few 100’s – 30,000 km/sec in the UV and a few 100’s – >100,000 km/sec in X-rays). • X-ray features span a factor of ~105 in ionization parameter indicating the presence of ions ranging from highly ionized (H-He - like Fe) to neutral, all in 1.5 decades in X-ray energy! • These “live” in very different regions of ionization parameter space and likely in different regions of real space. 10/28/2010 SEAL@GSFC

  6. X-ray spectrum of NGC 3783 Netzer+(03) MCG 6-30-15 Holczer+10 Crenshaw+03 10/28/2010 SEAL@GSFC

  7. BAL QSO: X-ray Absorptions • High-velocity outflows: v/c~0.1-0.7 in Fe XXV/XXVI X-ray Absorption line (Fe XXV) Spectral index vs. wind velocity X-ray absorber Chandra/XMM/Suzaku Effect of ionizing spectrum(!?) Fe resonance transitions Brandt+(09); Chartas+(09) 10/28/2010 SEAL@GSFC

  8. Galactic Black Hole (GBH) Binaries GRO J1655-40: • High ionization: log(x[erg cm s-1]) ~ 4.5 - 5.4 • Small radii: log (r[cm]) ~ 9.0 - 9.4 • High density: log(n[cm-3]) ~ 14 • M(BH)~7Msun • M(2nd)~2.3Msun Miller+(06) NASA/CXC/A.Hobart Chandra Data Miller+(08) 10/28/2010 SEAL@GSFC

  9. Our thesis (and hope) is that these diverse data (including those of galactic X-ray sources) can be systematized with a small number of parameters (2) (Elvis 2000; Boroson 2002 ) 10/28/2010 SEAL@GSFC

  10. Flows (accretion or winds) and their ionization structure are invariant (independent of the mass of gravitating object;ADAF) if: • Mass flux is expressed in terms of Eddington mass flux • The radius in terms of the Schwarzschild radius • The velocities are Keplerian 10/28/2010 SEAL@GSFC

  11. Absorption Measure Distribution (AMD) AMD(x) = dNH / dlogx ~ (logx)p where x = L/(n r2) (5 AGNs) column (0.02 < p < 0.29) column ionization ionization Holczer+(07) Behar(09)  presence of nearly equal NH over ~4 decades in x (p~0.02) 10/28/2010 SEAL@GSFC

  12. For radiatively driven winds one obtains Flows not driven Radiatively ! Column density decreases With increasing ionization 10/28/2010 SEAL@GSFC

  13. To AMD through MHD Winds Blandford+Payne(82) Contopoulos+Lovelace(94) Konigl+Kartje(94) Contopoulos(95) Murray+(95;98) Blandford+Begelman(99) Proga+Kallman(04) Everett(05) Schurch+Done(07,08) Sim+(08;10) & more… accelerated Konigl+Kartje(94) • Accretion disks necessarily produce outflows/winds (launched initially with Keplerian rotation) • Driven by some acceleration mechanism(s) • Local X-rays heat up and photoionize plasma along the way Need to consider mutual interactions between ions & radiation 10/28/2010 SEAL@GSFC

  14. Magnetically-Driven Outflows Magnetohydrodynamics (MHD) • (At least) 2 candidates: • GRO J1655-40 • Miller+(06,08) • NGC 4151 • Kraemer+(05) • Crenshaw+Kraemer(07) 11/19/2010 MSU/Physics

  15. MHD Disk-Wind Solutions (Contopoulos+Lovelace94) • Steady-state, axisymmetric MHD solutions (2.5D): (Prad=0)  5 “conserved” quantities: Energy, Ang.Mom., Flux, Ent., Rot. • Look for solutions that the variables separate 10/28/2010 SEAL@GSFC

  16. Assume Power Law radial dependence for all variables • Solve for their angular dependence using the force balance equation in the q-direction (Grad-Safranov equation). • This is a wind-type equation that has to pass through the appropriate critical points. 10/28/2010 SEAL@GSFC

  17. The density has a very steep q-dependence with the polar column being 103 – 104 smaller than the equatorial. The wind IS the unification torus(Konigl & Kartje 1994). MHD Wind Angular Density Profile e (q-p/2)/0.2 T. Fischer et al.(2012) 10/28/2010 SEAL@GSFC

  18. Simple Wind Solutions with n~1/r At small latitudes vt >> vp (disk-like) while at high latitudes vt ~1/r but vp ~ constant (wind-like). [cm-3] Poloidal velocity Density Launch site Toroidal velocity (Fukumura+10a) 10/28/2010 SEAL@GSFC

  19. With the above scalings • In order that n(r)~1/r, s = 1 and • The mass flux in the wind increases with distance!! (Behar+ 03; Evans 2011; Nielsen et al. 2011). Or rather, most of the accreting gas “peels-off” to allow only a small fraction to accrete onto the black hole (Blandford & Begelman 1999). • There is mounting observational evidence that the mass flux in the wind is much higher than that needed to power the AGN/LMXRB. • Feedback! Edot ~ mdot v2 ~r-1/2 ; Momentum input: Pdot ~ mdot v ~ logr Equal momentum per decade of radius! 10/28/2010 SEAL@GSFC

  20. By expressing BH luminosity in terms of dimensionless variables ( or ) the ionization parameter can now be expressed in the dimensionless variables • For s=1, x(r) ~ 1/r ; species “living” in lower x-space should come from larger distances. • The radiation seen by gas at larger distances requires radiative transfer thru the wind. 10/28/2010 SEAL@GSFC

  21. Calculate the photon and B-field densities 10/28/2010 SEAL@GSFC

  22. Compton Dominance Condition This condition depends only on one global Parameter, namely the wind mass flux rate! 10/28/2010 SEAL@GSFC

  23. A precise calculation can be carried out by computing the scattered specific intensity and then integrating over angles to obtain the energy density D 10/28/2010 SEAL@GSFC

  24. Ha – Bolometric Luminosity Using the scaling one can calculate n^2 V and then the Halpha luminosity By integrating out to x ~ 10^6 to obtain L Ha ~ M mdot^2 10/28/2010 SEAL@GSFC

  25. IR EmissionDust reprocessing: For n(r)~1/r, equal energy per decade of radius is absorbed and emitted as dust IR emission at progressively decreasing temperature. This leads to a flat nuFnu IR spectrum 10/28/2010 SEAL@GSFC

  26. 10/28/2010 SEAL@GSFC

  27. Should be modified to Include these winds … 10/28/2010 SEAL@GSFC

  28. (Note that different LoS can see different continua; X-ray and UV absorbers need not be identical) Microlensing technique (e.g. Morgan+08; Chartas+09a)  UV regions > X-ray regions (x ~10) torus 10/28/2010 SEAL@GSFC

  29. Thank you! 10/28/2010 SEAL@GSFC

  30. Summary We propose a simplistic (self-similar) MHD disk-wind model: • Key ingredients  mdot (column) LOS angle (velocity) Fn (SED; G, aOX, MCD…etc.) q (field geometry + density structure) This model (in part) can account for interesting observables: • Observed AMD (i.e. local column distribution NH as a function of x) • Observed windkinematics and outflow geometry: Seyferts ~100-300 km/s (Fe XVII); ~1,000-3,000 km/s (Fe XXV) BAL QSOs ~ 0.04-0.1c (UV C IV); ~ 0.4-0.8c (X-ray Fe XXV) 10/28/2010 SEAL@GSFC

  31. END 10/28/2010 SEAL@GSFC

  32. *Acceleration Process(es) • 1. Compton-heated wind (e.g. Begelman+83, Woods+96) • “ Central EUV/X-ray  heating a disk  thermal-wind” • IssueToo large radii… • 2. Radiatively-driven (line-driven) wind • (e.g. Proga+00, Proga+Kallman04) • “UV radiation pressure  accelerate plasma” • IssuesOverionization @ smaller radii… •  Ionization state freezing out… • 3. Magnetocentrifugally-driven wind • “Large-scale B-field  accelerate plasma” • Issue  Unknown field geometry… 10/28/2010 SEAL@GSFC

  33. Issues (Future Work) Wind Solutions (Plasma Field): • (Special) Relativistic wind • Radiative pressure (e.g. Proga+00;Everett05;Proga+Kallman04) Radiation (Photon Field): • Realistic SED (particularly for BAL quasars) • Different LoS between UV and X-ray (i.e. RUV > RX by x10…) • Including scattering/reflection (need 2D radiative transfer) (Ultimate) Goals: • Comprehensive understanding of ionized absorbers within a single framework (i.e. disk-wind) AGNs/Seyferts/BAL/non-BAL QSO with high-velocity outflows (e.g. PG 1115+080, H 1413+117, PDS 456 and more…)  Energy budget between radiation and kinetic energy… 10/28/2010 SEAL@GSFC

  34. Broad Absorption Line (BAL) QSOs • Became known with ROSAT/ASCA survey • Large C IV EW(absorb) ~ 20-50 A ~ 30,000 km/sec • ~10% of optically-selected QSOs • Faint (soft) X-ray relative to O/UV continua • High-velocity/near-relativistic outflows: • v/c ~ 0.04 - 0.1 (e.g. UV C IV) • v/c ~ 0.1 - 0.8 (e.g. X-ray Fe XXV) • High intrinsic column of ~ 1022 cm-2 (UV) • >~ 1023 cm-2 (X-ray) 10/28/2010 SEAL@GSFC

  35. Review on Absorption Features: • Crenshaw, Kraemer & George 2003, ARAA, 41, 117 (Seyferts) • Brandt et al. 2009, arXiv:0909.0958 (Bright Quasars) 10/28/2010 SEAL@GSFC

  36. Chandra survey Gallagher+(06) END 10/28/2010 SEAL@GSFC

  37. r~ ai-1Fo(Bo/vo)2r* Mdot(mass loss rate) ~ 10-6 Mo/yr Fo (ai/1AU)5/2 (M/Mo)-1/2 (Bo/1G)2 ~ 6x1019 g/sec Fo (ai/1AU)5/2 (M/Mo)-1/2 (Bo/1G)2 ~ 6x1013-16 g/sec (ai/1AU)5/2 for M=108Mo, Fo=0.0-0.1, Bo=1-10G 10/28/2010 SEAL@GSFC

  38. 10. Normal galaxies vs. BAL quasars Lya C IV Mg II Ha Hb Si IV Lya NV C IV broad absorption lines (P Cygni profiles) normal BAL 10/28/2010 SEAL@GSFC

  39. Ramirez(08) 10/28/2010 SEAL@GSFC

  40. 10/28/2010 SEAL@GSFC

  41. 2500 Å 2 keV ? Elvis+(94) Richards+(06) aox = 0.384 log (f2 keV / f2500 Å)  tells you X-ray weakness UV-bright, X-ray-faint! Chandra BAL QSO survey Gallagher+(06) 12. Quasars – SED (UV/X-ray property) 10/28/2010 SEAL@GSFC

  42. UV Luminosity vs.aox brighter in X-rays Define: Daox=aox -aox (Luv) fainter in X-rays log(Luv) (ergs s-1 Hz-1) 10/28/2010 SEAL@GSFC 228 SDSS Quasars with ROSAT(Strateva et al. 2005)

  43. X-ray G ~ 1.7 – 2.1 Log(NH) ~ 23-24 T(var) ~ 3.3 days (~10 rg) XMM-Newton data Chartas+(09) 10/28/2010 SEAL@GSFC

  44. (ii) Velocity dependence on LoS Face-down view (e.g. ~30deg)  low NH, low v/c Optimal view (e.g. ~50deg)  high NH, high v/c 10/28/2010 SEAL@GSFC Feb. 2010 @Japan

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