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New advances in photoionization codes:

New advances in photoionization codes:. How and What for ?. Barbara Ercolano, UCL. Photoionization models – How ?. Lexington 2000 codes (Pequignot et al. 2001, PASP 247, 533). Cloudy (G. Ferland) Harrington (P. Harrington) Ion (H. Netzer) Mappings (R. Sutherland)

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New advances in photoionization codes:

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  1. New advances in photoionization codes: How and What for? Barbara Ercolano, UCL New advances in photoionization codes, how and what for?

  2. Photoionization models – How? New advances in photoionization codes, how and what for?

  3. Lexington 2000 codes(Pequignot et al. 2001, PASP 247, 533) • Cloudy (G. Ferland) • Harrington (P. Harrington) • Ion (H. Netzer) • Mappings (R. Sutherland) • (Infant) Mocassin (B. Ercolano) • Nebu (D. Pequignot) • Nebula (R. Rubin) • XStar (T. Kallman) Ercolano et al., 2003, MNRAS 340, 1136 New advances in photoionization codes, how and what for?

  4. Lexington 2000 codes(Pequignot et al. 2001, PASP 247, 533) • Cloudy (G. Ferland) • Harrington (P. Harrington) • Ion (H. Netzer) • Mappings (R. Sutherland) • (Infant) Mocassin (B. Ercolano) • Nebu (D. Pequignot) • Nebula (R. Rubin) • XStar (T. Kallman) Ercolano et al., 2003, MNRAS 340, 1136 New advances in photoionization codes, how and what for?

  5. Ercolano et al., 2003, MNRAS 340, 1136 New advances in photoionization codes, how and what for?

  6. New advances – How ? • Atomic data updates • Time-dependence effects • Inclusion of dust RT • Expansion to PDR • Development of 3-D Codes New advances in photoionization codes, how and what for?

  7. New advances – How ? • Atomic data updates • Collision strengths & transition probs • Radiative+Dielectronic recombination • Recombination data for ORLs (R. Bastin) • Data for cold (0.5-2kK) ionized plasma (as suggested by ORL analyses) New advances in photoionization codes, how and what for?

  8. New advances – How ? • Atomic data updates • Time-dependence effects • Inclusion of dust RT • Expansion to PDR • Development of 3-D Codes New advances in photoionization codes, how and what for?

  9. Time-dependent effects • Shock ionization (Mappings III) • Source variation (PNe in recombination) • Short gas-flow time scales • Cloudy (Henney et al., 2005 ApJ, 621,328) (Henney et al., 2005 ApJ, 621,328) New advances in photoionization codes, how and what for?

  10. New advances – How ? • Atomic data updates • Time-dependence effects • Inclusion of dust RT • Expansion to PDR • Development of 3-D Codes New advances in photoionization codes, how and what for?

  11. Gas and Dust Interactions: the dust thermal balance Dust Cooling Photoelectric emission from grains Absorption of resonance emission lines Radiation from grains Absorption of UV photons Dust Heating Dust-gas collisions • Cloudy (Van Hoof et al., 2004, MNRAS 350, 1330) • Mocassin (Ercolano et al., 2005, MNRAS submitted) New advances in photoionization codes, how and what for?

  12. Effects of dust grains on emission lines ratios • Cloudy (Van Hoof et al., 2004, MNRAS 350, 1330) New advances in photoionization codes, how and what for?

  13. New advances – How ? • Atomic data updates • Time-dependence effects • Inclusion of dust RT • Expansion to PDR • Development of 3-D Codes New advances in photoionization codes, how and what for?

  14. Self-consistent Photoionization+PDR • PNe emission line spectra modified by PDRs • Radiation field on PDR comes from ionised region • Dust dominates the opacity in the PDR • Must include a chemical network • Cloudy • (Shaw et al., 2005, ApJ 624, 794;Abel et al., 2005, ApJ 609, 247) • Mocassin+UCL_PDR (Ercolano et al., in prep.) New advances in photoionization codes, how and what for?

  15. New advances – How ? • Atomic data updates • Time-dependence effects • Inclusion of dust RT • Expansion to PDR • Development of 3-D Codes New advances in photoionization codes, how and what for?

  16. 3D codes: What for? NGC6543 – The Cat’s eye Nebula NGC2392 – The Eskimo Nebula MyCn18 – The etched hourglass nebula NGC7009 – The Saturn Nebula Central region of Abell 30 Images from www.hubblesite.org New advances in photoionization codes, how and what for?

  17. Projected model images of NGC 3918 in three infrared fine-structure lines observed by the ISO SWS Ercolano et al., 2003, MNRAS 340, 1153 New advances in photoionization codes, how and what for?

  18. 3D photoionization codes chronology • 1990 Baessgen et al., A&A, 201, 237 • Fixed grid resolution, 6 most abundant elements included, OTS diffuse field • 1997 São Paolo, Gruenwald et al., ApJ, 480, 283 • More flexible grid, 12 elements included, iterative techniques for the diffuse field • 2003 MOCASSIN, Ercolano et al., MNRAS, 340, 1136 • Flexible grids, 30 elements included, Monte Carlo RT, diffuse field treated self-consistently • 2004 Wood, Mathis & Ercolano, MNRAS 348, 1337 • Monte Carlo RT - tailored for the study of Galactic HII regions • (2004 Nebu-3D, Morisset et al., MNRAS, 360, 499) • A quick pseudo-3D photoionization code New advances in photoionization codes, how and what for?

  19. 2D Projections • Ha • [NII] Sahai et al., 1999, AJ 118,468 • [OIII] • [OI] Neal et al. (in prep) New advances in photoionization codes, how and what for?

  20. 2D Projections • Ha • [NII] Sahai et al., 1999, AJ, 118, 468 • [OIII] • [OI] Neal et al. (in prep) New advances in photoionization codes, how and what for?

  21. The future for 3D photoionization • Study of diffuse field dominated regions – the Helix knots and tails? • Chemical inhomogeneities – ORL/CEL discrepancy? (Y. Tsamis) • Realistic models of spatially resolved objects • Interface with hydro-codes New advances in photoionization codes, how and what for?

  22. CAVEAT: Horses for courses!!! “Never use a sledge-hammer to squash a fly!!!“ (Anonymous referee) • 1D codes allow faster computations • Parameter space explored more efficiently • Large grids of models can be produced quickly • 1D codes can be used in the case of • Spatially unresolved objects • Diffuse field unimportant (Nebu 3D) … Moores law on the other hand…. New advances in photoionization codes, how and what for?

  23. Overview • Photoionization Codes: What for? • Photoionization Codes: How? • New Advances: How? • 3D codes: How & What for? • Near & near-ish future New advances in photoionization codes, how and what for?

  24. Photoionization models – What for? • Interpretation of spectroscopic observations to determine • Properties of ionizing star(s) • Gas density and elemental abundances • Electron temperature and ionization structure • Testing physical assumptions, atomic physics and astrophysical knowledge • e.g. charge exchange process, low temperature dielectronic recombination New advances in photoionization codes, how and what for?

  25. 3D (analytical) photoionization: How? • São Paolo code: • Descendent of 1D Aangaba (Gruenwald & Viegas, 1992), descendant of ‘early NEBU’ (Pèquignot et al, 1988) • Stellar and diffuse fields accounted for • Local radiation field is calculated taking into account attenuation from intervening cells • Several PNe modelled (Monteiro et al., 2000,2004,2005) • Distance determinations New advances in photoionization codes, how and what for?

  26. 3D (MonteCarlo) photoionisation: How? • Discrete description of radiation field (energy packets) • Simulating the individual absorption/emission/scattering events • Packets trajectories determined stochastically according to the local opacities and emissivities. • Gas properties determined by imposing ionisation balance and thermal equilibrium New advances in photoionization codes, how and what for?

  27. Gas and Dust Interactions: the dust thermal balance Photoelectric emission from grains Dust Cooling Gas Heating Radiation from grains Absorption of resonance emission lines Absorption of UV photons Dust Heating Gas Cooling Dust-gas collisions • Cloudy (Van Hoof et al., 2004); Mocassin (Ercolano et al., submitted) New advances in photoionization codes, how and what for?

  28. MOnteCArloSimulationSofIonisedNebulae(Version 2.01.16) … can treat … • Bipolar, irregular geometries etc.. • Density &/or chemical inhomogeneities • Multiple ionising sources • 3D gas &/or dust radiative transfer • … can provide … • Emission line intensity tables • Spectral energy distributions (SEDs) • 3D (gas &/or dust) temperature distributions • 3D ionization structures • Emission line(s), continuum band projections through any line of sight New advances in photoionization codes, how and what for?

  29. Heating and cooling contributions in knot J3 of Abell 30 Positive x Positive z Negative x Ercolano et al., 2003 MNRAS 344, 1145 photo: heating by photoionization dust: heating by photoelectric emission from dust grains coll: cooling by collisionally excited lines rec: cooling by recombination ff: cooling by free-free radiation rd/rg(core)= 0.077 rd/rg(env)= 0.107 New advances in photoionization codes, how and what for?

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