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Ionization patterns in the circumstellar medium of active galaxies

Ionization patterns in the circumstellar medium of active galaxies. Joss Bland-Hawthorn (AAO). Collaborator: P.R. Maloney (U Colorado). How much could we learn from millimag optical-IR photometry?. SMEX mission:

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Ionization patterns in the circumstellar medium of active galaxies

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  1. Ionization patterns in the circumstellar medium of active galaxies Joss Bland-Hawthorn (AAO) Collaborator: P.R. Maloney (U Colorado)

  2. How much could we learn from millimag optical-IR photometry? SMEX mission: 1.5m aperture, off-axis camera, differential photometer, space environment, long-term program NGC 7742 Seyfert 2

  3. 2001 TRACE Satellite observations of the solar limb...

  4. Optical-IR variability vs. `ionization cones’ • Both involve two or more of: • accretion disk activity (intrinsic) • circumnuclear properties (extrinsic) • illumination geometry (extrinsic) • beaming effects (intrinsic) • viewing angle (extrinsic) Is observed phenomenon intrinsic to source or extrinsic?

  5. AGNs can have far-reaching influence within ISM... (Begelman 1985) Even as late as 1987, astronomers were not ready to believe this. The assumption was that (a) most jets were orthogonal to the disk, (b) the recently discovered dust tori would block UVX radiation from hitting the disk. However, we now suspect that in low luminosity AGNs, the dust tori / accretion disks precess wildly. Frequently, the torus opening angle intersects the large-scale disk.

  6. MR 2251-178: the Largest Known Quasar Nebula (Shopbell, Veilleux, & JBH 1999) • One of the few radio-quiet quasars with a extended gaseous nebula • Spiral complex extends more or less symmetrically over ~ 200 kpc • M(nebula) < 6 x 1010 Msun (ionized) • Photoionized by the quasar • Smooth large-scale rotation, in opposite sense to the inner region of the galaxy • Morphology and large-scale rotation seem to rule out origin from cooling flow, past merger event, or interaction with nearby galaxy G1 • Favor a model in which the extended ionized nebula resides within a large complex of HI gas centered on the quasar H jet axis maximum vel. gradient Z = 0.0638

  7. Ionization Cones NGC 5252 • Arguably the best example of ionization bi-cone • The line-emitting gas is very extended (~ 40 kpc) and consists of a complex network of filamentary strands • Gas is photoionized by Seyfert 2 nucleus • Complex kinematics are best explained as the superposition of two inclined rotating disks • Origin: past galaxy merger event? (Tadhunter & Tzvetanov 1989; Wilson & Tzvetanov 1994; Morse et al. 1998) Contour: Green Continuum Grey Scale: [O III] 5007

  8. [OIII] HST imaging of Circinus H Veilleux & JBH 1997; Wilson et al 2001

  9. NGC 7213 H + [N II] 6583 + continuum • Line-emitting filament is located ~ 18.6 kpc from Seyfert 1 nucleus • Multi-line images and optical spectra show that the warm gas is not ionized by H II regions • Warm gas is blueshifted by 100 – 150 km s-1 with respect to systemic 19 kpc 5 kpc (Veilleux & Rupke 2001; Hameed et al. 2001)

  10. NGC 7213 HI 21 cm vs. H + [N II] • HI map reveals NGC 7213 to be a highly disturbed system suggesting a past merger event • Line-emitting filament seems to coincide spatially and kinematically with HI filamentary structure (NH ~ 1 x 1020 cm-2 near filament) 4 kpc (Hameed et al. 2001)

  11. HST [O III] (Macchetto et al. 1994) HI 21 cm (Brinks) NGC 1068 Boundaries of Ionization Cone ? • Line-emitting filamentary complex detected out to ~ 12 kpc from the nucleus, slightly beyond the HI edge 20 kpc Digital Sky Survey 10 kpc (Shopbell, JBH & Veilleux 2001) log(H) 20 kpc

  12. NGC 1068 (Shopbell, Bland-Hawthorn, & Veilleux 2001) log(H) log([O III]) N • Filamentary complex is seen in both Ha and [O III] 5007 • Likely source of ionization: AGN • Likely origin: ambient material illuminated by AGN 10 kpc

  13. X-ray ionization cone in NGC 1068 Young, Wilson, Shopbell 2001 Chandra observations

  14. NGC 1068 multi-band diagnostics 11um

  15. Other effects are dust or electron scattering out of the beam ( < 0.1)- see Sokolowski, JBH & Cecil 1991 e

  16. MAPPINGS (Sutherland & Dopita) Energy range: 1 eV to 12 keV • Predict w.r.t. H-beta • [NII] • [SII] • [OI] [OII] [OIII] • HeII • [NeIII] [NeV] • [Fe VII] [Fe X]

  17. Isotropic illumination through a solid torus R < 50 kpc Line ratios wrt H 0 2 Log U Log [OIII]/H

  18. Isotropic illumination through soft-edge torus R > 50 kpc grey opacity 7 0 Log [OIII]/[OI]

  19. Isotropic illumination through torus with opaque edges R > 50 kpc Cf. to grey cones, we get the reverse effect at the edges. The ionization goes up. -1 1 Log [OIII]/H

  20. Beamed illumination (intrinsic) R < 1 kpc R < 50 kpc -1 6 0 2 Log [NeV]/[NeIII] Log [OIII]/H

  21. Asymmetric illumination out to 10 kpc Log [OII]/[OIII] -2 0

  22. Concluding remarks • Accretion disks and starburst winds both influence ISM over scales of 10 kpc or more, either radiatively or through powerful winds • The ionization pattern in the circumnuclear ISM can provide important clues about the nature of the source or surrounding medium (a key area for IFUs, TFs on 8-10m class telescopes) • Should we be considering differential optical/IR photometry of AGNs to an accuracy of < 1 millimag?

  23. New class of edge-on ionized cones, e.g. CenA Find TTF image Also, N4945 with powerful Lx and diffuse gas. Does this have cone?

  24. But accretion disks are not the only phenomena to produce ionization cones... But accretion disks are not the only phenomenon to produce ionization cones...

  25. H + [N II] HIFI M 82 (Shopbell & JBH 1998; Shopbell et al. 2001) 11 kpc H + [N II] HST Devine & Bally 1999

  26. There are instances where powerful wind and illumination by accretion disk are both operating...

  27. NGC 3079: Starburst-Driven Superbubble (Veilleux et al. 1994; Cecil, JBH, Veilleux & Filippenko 2001) HST 1 kpc Red = HBlue = [N II] 6583Green = continuumResolution: 0.1”  8 pc Energetics:p(outflow) ~ (1–3) x 1047 f½dyn s-1; KE(outflow)~ (0.2-2.5) x 1055 f½ ergs where f > 0.003; LW (mech) ~ 1043 ergs s-1

  28. Large-Scale Outflow in NGC 3079 ? N 20 cm NGC 3079 1 kpc Radio Axis HI tail • The dwarf S0 galaxy NGC 3073 exhibits an elongated HI tail remarkably aligned with the nucleus of NGC 3079 • Ram pressure due to outflowing gas may be responsible for tail • If so: Routflow 50 kpc NGC 3073 20kpc (Irwin et al. 1987; Filippenko & Sargent 1992; Cecil et al. 2001)

  29. Galactic wind Shocked halo Shell fragments Shocked wind Free wind Disk Disk Starburst log (density) (Strickland & Stevens 2000)

  30. Summary • Recent technological developments have allowed the study of the warm ionized medium in the local universe down to unprecedented flux levels • Observations at these faint flux levels have detected ionized material on the outskirts of normal and active galaxies • Gas expelled from the galaxies by local and large-scale outflows • Ambient gas ionized by active nuclei and starbursts • This material can be used to constrain • The warm-gas cross-sections of nearby galaxies • The impact of star formation and nuclear activity in disk galaxies and their environments (e.g., metal abundance, heating, …) • The distribution, intensity and spectrum of the ionizing radiation escaping from the cores of starburst and active galaxies • Future (now!): • Broad- & narrow-band shuffle mode: doubles efficiency • Nod & shuffle mode: virtually eliminates systematic errors associated with sky line variations  pure Poisson noise  integrate as long as needed!

  31. Emission-Line Morphology of Normal Isolated Edge-On Spirals Ha Images • Thick ionized disks and/or filamentary structures are detected out to 1 – 5 kpc from the planes of the galaxies in the sample • Both the mass and extent of the extraplanar material in these galaxies appear to be correlated with the (local) surface density of star formation activity (Miller & Veilleux 2001) NGC 2188 NGC 2820 NGC 3044 NGC 4013

  32. Heating vs. ionization • Sokolowski 91 • Reynolds Haffner & Tufte 99 NII/H Te (104 K)

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