3. ELLIPSOIDS: BULGES, ELLIPTICAL GALAXIES, AND GLOBULAR CLUSTERS
3.1 Surface Photometry
 Review of techniques (photographic,CDD)
 Radial brightness profiles:
 Systematics
 Analytic fitting functions
 D galaxies: properties of cD halos
 Cores: groundbased and HST observations
3.2 Families of Ellipsoidal Stellar Systems
 Global and core parameter correlations
 Three kinds of stellar systems: bulges + ellipticals, Sphs, globulars
 Relationship between Sph and S + I galaxies: Introduction
3.3 The Fundamental Plane of Elliptical Galaxies
 Global and core parameter correlations
 Scalar virial theorem; derivation of the fundamental plane equations
 Implications for galaxy formation; M/L (L )
3.4 Stellar Dynamics:Observations
 Measurement techniques:
 crosscorrelation,Fourier quotient,Fourier correlation quotient,...
 Lineofsight velocity distributions (LOSVDs)
 Observations of rotation and velocity dispersion pro •les
 Velocity anisotropy: the _{ } diagram
 Observational confirmation of triaxiality and anisotropy:
 Minoraxis rotation
 Shapes of E galaxies:statistics of apparent shapes
 Isophote twists
 Dust rings:implications for E shapes
3.5 Isophote Shapes:Boxy and Disky Es
 Measurements of isophote shapes: a (4)/a
 Correlations of a (4)/a with physical properties
 Physical dichotomy of E galaxies into
 (1)HighL , nonrotating, boxy, anisotropic Es with cuspy cores, and
 (2)Mediumand lowL , rotating, disky, approximately isotropic and coreless Es
 Proposed revision of the Hubble sequence: boxy E –disky E –S0 –Sa –Sb –Sc –...–Im
 Exceptions: Boxy bulges and lowL boxy Es: origin
3.6 Collisionless Dynamics: Theory
 Stellar systems are fundamentally more complicated than gases:
 Characteristic times: crossing time; relaxation time
 Distribution function
 Fundamental equations of macroscopic stellar dynamics:
 Collisionless Boltzmann equation
 Poisson equation
 First moment equations =basic equations of stellar hydrodynamics:
 Second moment equations: tensor virial theorem
 Application to _{} diagram ==> anisotropy
3.7 Galaxy Models. I. f =f (E, L_{z} )
 Jeans Theorem
 Models with f =f (E ):polytropes,isothermals,King models
 Emphasize:similarities between stellar dynamical and gas case (i.e.,stars)
 _{}
 Core masstolight ratios
 Models with f =f (E,L_{z} )
3.8 Globular Cluster Observations and Models
 Density distributions
 Velocity dispersion profiles
 Models with a range of stellar masses m
3.9 Stellar Orbits in Ellipsoidal Stellar Systems
 Orbits in a spherical potential
 Orbits in axisymmetric potentials: classical integrals
 Orbits in triaxial potentials
3.10 Galaxy Models.II.Galaxy =_{} weight_{i} orbit_{i}
 Schwarzschild ’s method; examples
 Spherical maximum entropy models; examples
 Axisymmetric maximum entropy models; examples
3.11 Dynamical Evolution of Ellipticals and Globular Clusters: Theory
 Phase mixing and violent relaxation
 Origin of the _{}density distribution
 Twobody encounters and relaxation
 Heat capacity of a selfgravitating stellar system is negative
 Core collapse: single_{} simulations
 Stopping core collapse via binaries
 Gravothermal oscillations
 Complications: range of _{}, primordial binaries, stellar evolution, physical stellar collisions, stellar coalescence, runaway stellar mergers,...
 External influences:
 Tidal effects
 Disruption of globular clusters by galactic disk shocking
 Relation between present and primordial globular cluster population
3.12 Dynamical Evolution of Ellipticals and Globular Clusters: Observations
 Postcorecollapse density distributions in globulars
 Mass segregation
 Stellar population gradients:blue stragglers
 Stellar population gradients in bulges and Es <== effects of high stellar density
3.13 Supermassive Black Holes (BHs)in Galactic Nuclei
 Brief motivation: nucelar activity (see §9)
 Origin of seed BHs via evolution of dense stellar systems
 Stellardynamical search for BHs
 Gasdynamical search for BHs
 BH demographics
 Flashes when stars are accreted by BHs
