1. SMP: Supermassive Black Holes Faber-Jackson vs. Tully-Fisher
ASTC22. Lectures L20
SMP: Supermassive Black Holes
Faber-Jackson vs. Tully-Fisher
SMP on SMBH
Are these two empirical laws similar? The same?
Isothermal spheres
Isothermal distribution functions
Isothermal singular sphere
Isothermal non-singular sphere
Conclusions for the magnitude of dynamical friction in
dark halos: the reason for efficient mergers
Rotation and flattening of elliptical galaxies: only a weak
connection

3. Even the fantastic resolution of
the VLBI radio interferometry
cannot resolve the central engine.
The dot in the lower left corner is
of order 6 Schwarzschild radii,
i.e. several times the size of the
black hole event horizon, from
within which light or information
cannot escape.

6. Empirical correlation exists between the supermassive black hole mass
and the luminosity (and thus mass) of the bulge of the host galaxy, M87 is
shown in a red circle

7. SMP on SMBHs

8. Tully-Fisher relationship, a correlation between the luminosity
and rotation for disk
galaxies
Log Vc
-2.5 log L

9. Faber-Jackson relationship:
Luminosity ~ sigma^4
applies to ellipticals
Tully-Fisher relationship
Luminosity ~ (Vc)^3.85
applies to disk galaxies
but the two are almost identical:
both the disks and the ellipticals
are immersed in the same type
of dark halos which determines
the maximum Vc via potential
well depth.

12. (sorry, that’s
my teenage
daughter)

13. Good for modeling
flat-Vc galaxies
in dark halos

16. ...so this is one major reason why
mergers of galactic systems are
so rapid (a few to a few dozen periods)

17. One more empirical correlation: between rotation and flattening of ellipticals,
which can be understood based on stellar dynamics
Fastest rotation
according to theory
But remember: theory gives the upper envelope only. Most ellipticals are
NOT supported or flattened by rotation. They simply are not relaxed; flattening
comes from initial conditions, including geometry of encounter.