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3D spectrography V – Density waves in the inner regions of galaxies

3D spectrography V – Density waves in the inner regions of galaxies. D ensity W aves in galaxies. Warps. Spirals. > 50% of grand-design. All disk galaxies?. Lindblad, Lin & Shu (60’s). (Sancisi 76). Lopsidedness. Bars. > 70% of spirals?. Very common. (Kamphuis et al. 91).

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3D spectrography V – Density waves in the inner regions of galaxies

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  1. 3D spectrographyV – Density waves in the inner regions of galaxies

  2. Density Waves in galaxies Warps Spirals > 50% of grand-design All disk galaxies? Lindblad, Lin & Shu (60’s) (Sancisi 76) Lopsidedness Bars > 70% of spirals? Very common (Kamphuis et al. 91)

  3. Role of Density Waves • Torques • Local density enhancements crowding, shocks • Angular momentum transfer • Dynamical diffusion / heating • Link with: Secular evolution? Star formation, starbursts? • AGN? NGC 4314

  4. IDW: Towards the centre • Shorter dynamical timescales !! • Peaked density distributions (cusps, BHs) • A priori lower fraction of dark matter (besides the BH), • Axisymmetrisation? • Importance of self-gravity A few numbers: 100 pc  106 yrs at 100 km/s • Duty cycle of an AGN? 107– 108yr • Average Fueling rate? 0.001 – 1 Msun / yr • Total mass used? 104-108 Msun

  5. Epicycles and resonances For a disk (potentialF): W 0th Ordre Natural frequency of the system W: angular frequency

  6. Epicycles and resonances For a disk (potentialF): W 0th Order k Natural frequencies of the system: W: circular frequency k : radial epicyclic frequency

  7. Epicycles and resonances For a disk (potentialF): W Rotating with an angular velocity k Natural frequencies of the system: W: circular frequency k : radial epicyclic frequency

  8. W k Epicycles and resonances For a disk (potentialF): Natural frequencies of the system: W: circular frequency k : radial epicyclic frequency

  9. Precession • Precession of elliptical orbits:W -k / 2 Alignement Non Alignement Structure with rigid rotation Wp if: Wp =W -k / 2 = CTE

  10. Propagation, amplification • Potential is a superposition of spiral perturbations CR ILR If Q > 1: evanescent waves

  11. Bars and angular momentum • Gas outside the CR • Gas between the CR and l’ILR OLR ILR Change of orientation of the orbits at the resonances : gradual change for the gas

  12. E N NGC 1068 Lai (CFHT, I + K + Brg)

  13. NGC 1068 with SAURON E N Coll.: K. Fathi, H. Wozniak, P. Ferruit, R. Peletier & the SAURON team

  14. Modelling NGC 1068 • Mass model: NIR Photometry and Velocity curve • Stars and gas: ‘’Ringberg standards’’ Coll.: K. Fathi, H. Wozniak, P. Ferruit, R. Peletier & the SAURON team

  15. Gas… E N Model SAURON Coll.: K. Fathi, H. Wozniak, P. Ferruit, R. Peletier & the SAURON team

  16. And stars… E N SAURON Model Coll.: K. Fathi, H. Wozniak, P. Ferruit, R. Peletier & the SAURON team

  17. IDW: Inner bars versus AGN? CO bandhead (2.3 mm) ISAAC / VLT The DEBCA project SDD H band NGC 1808 (starburst) minor major Emsellem, Greusard, Combes et al. 01, A&A 368, 52

  18. StellarDispersion Drops in 2D Gnd based Image 7' x 7' Stars NGC 3623(Sa) SAURON / WHT

  19. Nuclear spirals Regan & Mulchaey 99, AJ 117, 2676 (HST, WFPC2 / NICMOS) 100 pc 1.6 mm

  20. IDW: Inner spirals DSS 4’x4’ NGC 2974 E4 Vs = 1866 km/s D ~ 25 Mpc Mdust ~ 1.5 106 Msun (IRAS) MHI ~ 8 108 Msun (Kim et al. 1988) MHII ~ 3 104 Msun (Buson et al. 1993) Emsellem & Goudfrooij 03, MNRAS

  21. LRF 240 pc [NII]+Ha IDW: Inner spirals NGC 2974 WFPC2 E(V - I) Emsellem & Goudfrooij 03, MNRAS

  22. And the winner is … Emsellem & Goudfrooij 03, MNRAS

  23. The inner bar: Integral Field data V NGC 2974 s TIGER – CFHT (3D Deconvolution) Emsellem & Goudfrooij 03, MNRAS

  24. Optical NIR NGC 3504: m=1 modes WFPC2 / HST OASIS / CFHT NGC 3504 PUEO / CFHT I band arcsec Combes et al. Coll.: Didier Greusard, Françoise Combes

  25. Ha OASIS / CFHT NGC 3504: m=1 modes [NII] WFPC2/HST F606W NGC 3504 [OI] Vgas PUEO/CFHT K Coll.: Didier Greusard, Françoise Combes

  26. F814W STIS Berman 01, A&A 371, 476 UV peak arcsec Bulge & Nucleus 5 pc arcsec gas flow model kpc HRCAM Absorption map model kpc IDW: Towards the BH M 31 Bacon, Emsellem, Monnet, et al. 1994, Emsellem & Combes 1997: Mbh = 7 107 Msun

  27. M31 – Kepleri an m=1 N body simulation OASIS / CFHT V s I Bacon, Emsellem, Combes, et al. 01, A&A 371, 409

  28. Summary - Conclusions • Density waves have an important role in redistributing the dissipative component and reshaping the galaxy (nuclear disks) Resonances!! • Density waves are present in the central regions of galaxies. • nuclear bars versus central starbursts (cold system) • nuclear spirals are common but have low amplitudes … • nuclear m=1 modes may be common • keplerian m=1 (M 31) • The presence of gas is critical • 3D spectrography is required (again…) • Central starburst – AGN: evolution sequence? • Time-scales! (fueling the nucleus, starburst, AGN, dynamical heating …)

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