Surface Brightness Profile - NGC 3379 (giant elliptical) Surface Brightness (mags/arcsec2) Dashed line is a deV law r1/4

King Models - A Family of Curves deV law would be a straight line on this plot Note: “Isothermal” sphere is classic model where density is r( r ) ~ 1/r2 Surface Brightness r1/4

Error Function

King Models and Observed Objects NGC 6388 Circles: globular cluster NGC 6388 Squares: globular cluster NGC 5053 Triangles: Sculptor dwarf galaxy NGC 5053 Sculptor Dwarf Galaxy

Giant Elliptical NGC 4472 (c = 2.35) SDSS image Solid line is King Model with c = 2.35

deV vs. King: NGC 3379 Dots: observations Dashed line: deV law Solid line: King model, c = 2.2

Two Galaxies in Same Cluster: Dwarf E and Giant E Dashed - Giant E, r1/4 Solid - Dwarf E, exp[-r/rs]

cD Galaxy - The Biggest of the Big Line: deV Line: deV law ?

Schechter Luminosity Function The most intrinsically luminous galaxies are primarily red in color and are rare The most intrinsically faint galaxies are the most numerous and are primarily blue in color (irregulars vastly outnumber dwarf E) blue red

“Violent Relaxation” of Star Cluster “cold” start minimum size maximum size end

Density Profile: Before and After Violent Relaxation Uniform density sphere (dashed line) at start R1/4 law at end (squares + solid line)

Distribution of Stellar Energies: Before, During, and after Violent Relaxation start end