3d spectrography iv – the search for supermassive black holes

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Padova 03 3D Spectrography 3D Spectrography 3D Spectrography IV – The search for IV – The search for supermassive supermassive black holes black holes

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3D Spectrography IV – The search for supermassive black holes. The search for supermassive black holes. Most (present day) galaxies should contain a central massive dark object with a mass M ● of 10 6 to a few 10 9 M sun. Ferrarese & Merritt 2000 (see also Gebhardt et al. 2000, 2003). - PowerPoint PPT Presentation

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Diapositive 1black holes
Padova 03
3D Spectrography
The search for supermassive black holes
Most (present day) galaxies should contain a central massive dark object with a mass M of 106 to a few 109 Msun
Ferrarese & Merritt 2000 (see also Gebhardt et al. 2000, 2003)
Padova 03
3D Spectrography
The holy grail for dynamicists:
The distribution function: f
(x, y, z, vx, vy, vz, t)
Padova 03
3D Spectrography
Disks
Energy E
Radial range large enough to include all of the mass
Jeans’ theorem
Padova 03
3D Spectrography
Angular momentum Lz
Linear grid from the minimum Lz (=0, radial orbit) to the maximum Lz (circular orbit) at this Energy
Orbital initial conditions:
The angular momentum
Third integral I3
Parametrized with starting angle atan(zzvc/Rzvc) on the ZVC, from the minimum I3 (=0, planar orbit) to maximum I3 (thin tube orbit) at these E and Lz
Cretton et al. 1999
Integrate nE x nLz x nI3 orbits and store on
Intrinsic, polar grid:
Store fractional contributions in …..
Photometric:
Mass model integrated over grid cells, normalized by total galaxy mass
Kinematic:
Orbital Weights
Least squares problem:
Solve for orbital weights vector j>0 that gives superposition i j Oij closest to Dj
NNLS or other least-squares methods
Quality of fit determined by
Padova 03
3D Spectrography
Mbh
M/L
Derive orbital libraries for different values of MBH and M/L …
Solve the matrix problem for each library (NNLS)
Draw χ2 contours, and find best fit
3s
Padova 03
3D Spectrography
M 32
Evidences for the presence of a massive black hole
Best study so far?: Schwarzschild model on long-slit data and HST/FOS spectrography (van der Marel et al. 1997, 1998)
Results:
STIS/HST data have been published by Joseph et al. (2001)
Padova 03
3D Spectrography
New dataset:
SAURON maps in the central 9”x11” (de Zeeuw et al. 2001)
STIS data along the major-axis (Joseph et al. 2001)
V
MBH in agreement with van der Marel et al. 1998
(Verolme, Cappellari et al. 2002)
3 level
Padova 03
3D Spectrography
3
level
Padova 03
3D Spectrography
M 32
regularized
Padova 03
3D Spectrography
Vitesse (km/s)
Dispersion (km/s)
Padova 03
3D Spectrography
Consistent with photometric disk
Comparison of Ca / Hb kinematics implies that disk > 6 Gyrs old
Slow rotator =1:3 dissipationless merger?
Mc Dermid et al. 2002
Padova 03
3D Spectrography
There exists an infinity of models having a given F(r)
Axisymmetric case:
General situation: f(E, Lz, I3)
????
Which minimum ??
Padova 03
3D Spectrography
Summary - Conclusions
3D spectrography is required to probe the morphology and dynamics of nearby galaxies :
Mapping of the gas/stellar kinematics and populations
Probing the full complexity of these objects
Internal structures
More specifically :
What structures should we expect at the 10 pc scale ?
Need for a general tool to model the dynamics of galaxies
Need to break the degeneracy which may exists in models
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