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AGN10-dall ’ orizzonte degli eventi all ’ orizzonte cosmologico Roma 11/09/2012

Phisical properties of dense molecular gas in centres of Seyfert galaxies. Eleonora Sani. Co-Is: Davies, Sternberg, Gracia-Carpio, Hicks, Tacconi, Genzel, Engel, Vollmer, Schinnerer, Garcia-Burrillo Usero, Orban de Xivry.

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AGN10-dall ’ orizzonte degli eventi all ’ orizzonte cosmologico Roma 11/09/2012

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  1. Phisical properties of dense molecular gas in centres of Seyfert galaxies Eleonora Sani Co-Is: Davies, Sternberg, Gracia-Carpio, Hicks, Tacconi, Genzel, Engel, Vollmer, Schinnerer, Garcia-Burrillo Usero, Orban de Xivry AGN10-dall’orizzonte degli eventi all’orizzonte cosmologico Roma 11/09/2012

  2. Outline • Introduction • Torus structure • AGN-SF connection • Stellar and molecular gas kinematics • Motivation: • Trace the dense molecular gas • The origin of huge velocity dispersion • Results: • - PdBI data cubes and observables • - DYSMAL • - Can the torus form stars? E. Sani AGN10 Roma 11/09/2012

  3. Torus structure • Smooth (continuous) • Clumpy (discrete) Dust distribution: Pier & Krolik 1992; Granato & Danese 1994 Efstathiou & Rowan-Robinson 1995; Shartmann+05; Fritz+06 Nenkova+02, +08; Honig+06; Schartmann+08 • Stellar radiation pressure(Thompson+05; Ballantyne 2008) • Supernovae explosions(Wada & Norman 2002) • Stellar winds(Nayakshin & Cuadra 2007) • External gas accretion (Vollmer+08) Nuclear star formation can play an important role E. Sani AGN10 Roma 11/09/2012

  4. AGN-SF connection SF happens in all types of AGN (Schweitzer+06, Veilleux+09) even in the nuclear region (R < 200 pc) (Cid Fernandes +04) SF enhanced for MBH < 107 M L/Ledd > 0.5 BH growth and SF happens simultaneously Sani+10 E. Sani AGN10 Roma 11/09/2012

  5. AGN-SF with high spatial resolution Davies+07 Recent (~40 Myr ago) but no longer starburst in the inner 100 pc (with spatial resolution ~10 pc) • H2 1-0(S1) traces warm molecular gas • at centres v/σ < 1 with σgas~50-100 km/s • distribution must be vertically extended with gas & stars spatially mixed • random bulk motions must account for σgas in AGN v. dispersion H2 flux velocity Hicks+09 E. Sani AGN10 Roma 11/09/2012

  6. Molecular gas tracers • 1-0S(1) H2 traces hot component of the gas (~1000 K) at the edges of clouds • 1-0S(1) H2 accounts for 10-6-10-5 of the total gas mass • it is not straightforward to derive the vertical extent of the torus • and the origin of the huge σgas Sani+12 • HCN(1-0), HCO+(1-0) probe cold (~10-100 K) and dense (n >3x104 cm-3) molecular gas(i.e. ~100-500 times the density traced by CO rotational transitions) • Close to the AGN HCN, HCO+ are stronger than CO • Chemistry modified by the AGN radion has little impact on the gas kinematcs <1” resolution with PdBI E. Sani AGN10 Roma 11/09/2012

  7. Kinematics of the dense gas ~1” resolution from PdBI – NGC 3227, 2273, 4051, 6951 (now also NGC 3079, 5033, 6764) Directly observable constraints: • major & minor axis size • Integrated line width FWHM~70-210 km/s • Separation + PA of the red/blue channels Sani+12

  8. Modelling the kinematics Use DYSMAL (Cresci +09, Davies +11) -Gaussian distribution for the luminosity and mass profiles -Fixed parameters: ϑ and PA • -Elliptical beam (beam smearing is a key aspect of dynamical modeling) • -Free parameters: R, H, MR • Thin disk • -Line width is only ~2/3 of that observed • Thick disk • -Can reproduce all observed characteristics • -Intrinsic dispersion is 25-50 km/s for HCN and HCO+ • (about ~50% of H2 1-0S(1) reported by Hicks+09) • -Dispersion is due to a combination of beam smearing of velocity • gradients as well as V/σ~R/H~3-4 Q = √3 H 1 R (1+3*H2/R2) fgas • Toomre Q parameter: • Q/Qc>1 always, i.e. dense gas is turbulent with NO ongoing SF

  9. SF within the Torus? SF within 450 pc 305 pc 180 pc 370 pc NGC 6951 PdBI • NGC 3227: nuclear (<30 pc) SF is no more occurring (Davies +06) • NGC 2273, NGC 3227, NGC 6951 show a circumnuclear stellar ring (Martini +03, Davies +06, Krips +07) with a decreasing stellar dispersion comp. to the nucleus (Barbosa +06) • NGC 4051: PAH3.3 not detected within the central 50 pc (Rodrguez-Ardila & Viegas 2003) NGC 2273 K-band LBT Pisces+Flao SF located in a circumnuclear ring

  10. Phase III: the mass acc. rate decrease significantly. The collisional disk become thin and transparent. Phase II: SN explosions clear the intracloud medium leaving a massive, geometrically thick collisional disk of dense gas clouds The model: starburst & torus evolution Phase I: short, massive gas infall generates a massive turbulent disk (Q~Qc) where SF occurs. Thick disk Q > Qc Vollmer, Beckert, & Davies 08

  11. Conclusion & Future Work • We observed 4 Seyfert galaxies with the PdBI tracing HCN and HCO+ molecular lines. The line emission is (marginally) resolved. • We measured morphological (dimension & position angle) and kinematical (channel separation & integrated line width) parameters. The most remarkable feature is the line width FWHM ~ 70-210 km/s • Observed parameters are well reproduced by a thick (R/H = V/σ) taking into account the beam smearing. • Increase the statistics: now available data for 3 more sources. • Add other AGN types to trace the torus structure in different environments and its evolution. • Use tracers at 1.3mm, e.g. HCN(3-2), to constrain the chemistry

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