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DARK MATTER IN GALAXIES Paolo Salucci (SISSA). Dennis: Rotation Curves, Dark Matter, Nature of, Role of Baryons. Importance of the topics but low interest.

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Presentation on theme: "DARK MATTER IN GALAXIES Paolo Salucci (SISSA). Dennis: Rotation Curves, Dark Matter, Nature of, Role of Baryons. Importance of the topics but low interest."— Presentation transcript:

1 DARK MATTER IN GALAXIES Paolo Salucci (SISSA)

2 Dennis: Rotation Curves, Dark Matter, Nature of, Role of Baryons. Importance of the topics but low interest from Scientific Community

3 Persic, M., S. P. 1988, MNRAS, Dark and visible matter in spiral galaxi Persic, M.; S.P.; Stel, F MNRAS, 281, 27 The universal rotation curve of spiral galaxies - I. The dark matter connection Gentile, G.; S. P.; Klein, U MNRAS, 351, 903 The cored distribution of dark matter in spiral galaxies S.P MNRAS The universal rotation curve of spiral galaxies out the virial radius II Persic, M., S. P., 1988, MNRAS, Dark and visible matter in spiral galaxies Persic, M.; S. P., Stel, F MNRAS, 281, 27 The universal rotation curve of spiral galaxies - I. The dark matter connection Gentile, G.; S. P., Klein, U MNRAS, 351, 903 The cored distribution of dark matter in spiral galaxies S.P MNRAS The universal rotation curve of spiral galaxies out the virial radius II S.P ADS reviews

4 Central surface brightness vs magnitude The Realm of Galaxies 15 mag range, 4 types, 16 mag arsec -2.range The Realm of Galaxies 15 mag range, 4 types, 16 mag arsec -2.range

5 Stellar distribution L(R/R D )/L T is independent of luminosity The light surface profile I(r) = I 0 exp (-R/R D ). A mass lenght-scale luminosity independent? 1000 objects Colors are radially constant 3R D

6 RTF: magnitude vs log different radii x i R D, [ x i =0.5,1,…5] 3 samples (600, 89, 78) M =a i + b i log V(x i ) No relationship ↔ V does not trace the mass Vmax Does the kinematics probe the mass distribution of galaxies ? Yes. Radial Tully Fisher Inner mass distribution

7 Radial TF

8 Slope and scatter of the TF-relations: M B = a i + b i log V(x i ) The slope increases from -4 to -8. No change in slope ↔ no DM or a constant fraction of DM The minimum scatter 0.2 mag at 2.2 R D

9 MODEL V traces the potential DM emerges at large radii

10 Modelling the very inner circular velocities: light traces the mass

11 Phenomenology of spiral kinematics The rotation curves 3200 coadded individual PSS C+06

12 RC slopes vary among galaxies and within them. They indicate the presence and the amount of dark matter. At 3 disk length scales

13 The URC concept fixed L and x =R/R D, the Cosmic Variance of V( x,L ) is one order of magnitude smaller than the variations that: ➲ in each galaxy, V( x ) shows as x varies. ➲ V( x ) each x, in galaxies of different L

14 3.avi.. /Desktop/3.avi

15 Rotation curve modelling. ➲ : from I-band photometry ➲ : from HI observations ➲ dark halos with constant density cores dark halos with “cusps” (NFW, Moore) HI-scaling MOdified Newtonian Dynamics..t4bt5b

16 NFW Halos Burkert Halos

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18 Modelling the Universal Rotation Curve dark matter contribution Stars

19 DM fraction core radius halo central density luminosity

20 The role of the slope of the RC

21 Halo central density vs core radius scaling r 0 = (r 0 /kpc) -1 g/cm 3 dSph B URC WL

22 Virial halo masses and

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24 Christiane Frigerio Martins Weak lensing With a density profile we model the tangential shear Obtain the structural free parameters. Same results as those obtained from RCs. Burkert profile provides excellent fit, better than NFW. NFW B

25 DM halo density: observations vs simulationsdensity

26 URCL NFW URCH

27 Dark halos from simulations Halos form hierarchically bottom-up via grav. amplifications of initial density flucts. Most evident property: CENTRAL CUSP cuspy NFW density profiles disagree with observed kinematics. cuspy NFW density profiles disagree with observed kinematics. comparison galaxy by galaxy and of coadded kinematics. comparison galaxy by galaxy and of coadded kinematics. The cusp vs core issue NFW HALOS Fit badly the RCs Unphysically too low stellar mass-to-light ratios Unphysically too high halo masses Navarro, Frenk & White, ApJ 462, 563 (1996) Bullock et al., MNRAS 321, 559 (2001)

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29 A test case: ESO 116-G12 gas stars halo Cored halos the best fits

30 50 objects investigated NFW inconsistent

31 Theory Obis ssw Obs Theory decisive DDO 47: a decisive case NFW

32 Results from Trieste: analysis of high quality RCs URC fits to RCs DDO 47 Borriello & Salucci, MNRAS 323, 285 (2001) Gentile, Tonini & Salucci, A&A 467, 925 (2007)Gentile et al., ApJ 634, L145 (2005)

33 DDO 47: non circular motions? R V ( minor axis) Triaxial halos predictions

34 A Universal Mass Profile Walker et al 09

35 L CDM Universal Rotation Curve from NFW profile and MMW theory

36 ➲ AN INTRIGUING PROPERTY

37 A matter enigma

38 DM in early-types: weak+strong lensing 22 bright E/S0s at z ~ 0.2 (SLACS: Gavazzi et al. 2007)

39 DARK MATTER IS PRESENT IN GALAXIES IT IS STRONGLY RELATED TO THE LUMINOUS MATTER THERE IS A SOLID EMPIRICAL SCENARIO

40 We can uniquely mass model a RC disk-halo components, known surf phot, reliable V(R) and dV/dR, resolution ~ 0.3 R D

41 A way out? angular momentum exchange between baryons and DM Tonini Lapi Salucci cusp core


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