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MHD Accretion-Disk Winds as AGN X-ray Absorbers ~ Seyfert galaxies to quasars ~

MHD Accretion-Disk Winds as AGN X-ray Absorbers ~ Seyfert galaxies to quasars ~. Demos Kazanas Keigo Fukumura Astrophysics Science Division Code 663, NASA/GSFC Ehud Behar ( Technion , Israel) John Contopoulos (Academy of Athens, Greece ). ApJ (2010), 715, 636

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MHD Accretion-Disk Winds as AGN X-ray Absorbers ~ Seyfert galaxies to quasars ~

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  1. MHD Accretion-Disk Winds as AGN X-ray Absorbers~ Seyfert galaxies to quasars ~ Demos Kazanas Keigo Fukumura Astrophysics Science Division Code 663, NASA/GSFC Ehud Behar (Technion, Israel) John Contopoulos (Academy of Athens, Greece) • ApJ (2010), 715, 636 • ApJ (2010), 723, L228 Credit: NASA/CXC 10/28/2010 SEAL@GSFC

  2. The Scientific Method It is a capital mistake to theorize before one has the data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts. Sir Arthur Conan Doyle It is also a good rule not to put too much confidence in experimental results, until they have been confirmed by theory. Sir Arthur Eddington First you get your facts; then you can distort them at your leisure. Mark Twain 10/28/2010 SEAL@GSFC

  3. Some Facts • 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. For radiatively driven winds one obtains 10/28/2010 SEAL@GSFC

  10. 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

  11. 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

  12. 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

  13. With the above scalings • In order that n(r)~1/r, s = 1 and • The mass flux in the wind increases with distance!! 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! (talk by J. Ostriker) 10/28/2010 SEAL@GSFC

  14. 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 (see Keigo Fukumura’s talk). 10/28/2010 SEAL@GSFC

  15. 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 (yesterdy) 10/28/2010 SEAL@GSFC

  16. Simple Wind Solutions with n~1/r (q=1) Assume: M(BH) = 106 Msun, G~2 (single power-law), LX ~ 1042 erg/s, mdot ~ 0.5, rad. eff. ~ 10%, n(in) ~ 1010 cm-3 [cm-3] Poloidal velocity Density Launch site Toroidal velocity (Fukumura+10a) 10/28/2010 SEAL@GSFC

  17. 10/28/2010 SEAL@GSFC

  18. (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) 10/28/2010 SEAL@GSFC

  19. Dust 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

  20. Conclusions, Tests • All accreting BH have winds with velocities reaching v~0.5 c! We do not perceive them because they are highly ionized. • While NH and x are scale invariant for MHD flows the invariance is broken by atomic physics and radiative processes: • Gas densities scale like ~1/M implying that forbidden lines should not be present in the galactic LMXRB spectra. • Low ionization species are also absent in LMXRBs because the size of winds is limited by the presence of the companion. • The dust sublimation distance in LMXRBs is generally beyond the edge of the disk  No Sy2-like IR spectra for galactic sources. 10/28/2010 SEAL@GSFC

  21. Apply the model to BAL QSOs by changing only aOX: The decrease in ionizing X-rays allow for FeXXV very close to the BH  hi FeXXV velocity, absorption of CIV forming photons  CIV forms also at small distances leading to hi CIV velocity (but smaller than that of FeXXV). Injected SED (Fn) Log(density) • mdot = 0.5 • kT(in) = 5eV • GX = 2 • aOX = -2 Fukumura+(10b) 10/28/2010 SEAL@GSFC

  22. Correlations with Outflow Velocity Velocity Dependence on SED (X-ray) • X-ray data of APM 08279+5255 from Chartas+(09) • Model from Fukumura+(10b) 10/28/2010 SEAL@GSFC

  23. Conclusions (final) • We have produced an MHD model for ionized AGN outflows with 3 parameters: mdot (dimensionless), inclination angle q, and aOX. However the relation between and aOXand luminosity Implies that AGN winds can be described with only two parameters . So there is hope for understanding them! 10/28/2010 SEAL@GSFC

  24. 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

  25. END 10/28/2010 SEAL@GSFC

  26. *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

  27. 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

  28. 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

  29. 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

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

  31. 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

  32. 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

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

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  35. 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

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

  37. 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)

  38. 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

  39. (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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