Cores of Early-Type Galaxies

摘要: Systematic study of galaxy cores has become possible through improved understanding seeing and the reduction photometric errors by use CCDs. Many are well resolved in a photometry program with Canada-France- Hawaii Telescope (median stellar FWHM =0.″80). Core profile shape correlates luminosity L: brightest galaxies have isothermal profiles; fainter ellipticals bulges profiles that do not completely flatten inward into core. This may be due to velocity anisotropics. parameters correlated: more luminous larger core radii central surface brightnesses. Large deviations suggest special events: Fornax A too small bright for its luminosity; it remnant merger smaller galaxy. mass- to-light ratio M/L ∝ L 0.2 , as expected from metallicity-luminosity relation. kinematic search shows strong evidence black hole M31 weaker M32 NGC 3115. The nucleus rotates very rapidly but an outer dispersion only 107 km s-1. implies is disk; formed gas falling center. Rapid rotation > 241 ±7 s-1 imply v ≳ 20 – 35. Velocity anisotropics major uncertainty because rapid rotation. Therefore there nuclear point mass ∼ 2 x M ⊙.