1. 4.3 Photometry of Elliptical Galaxy Skarma Kim

2. Contents Radial surface-brightness profile - de Vaucouleurs R 1/4 law - cD galaxies - Dwarf elliptical galaxies - Centers of elliptical galaxies

3. Radial surface-brightness profile de Vaucouleurs R 1/4 law

4. The numerical factor 3.33 is chosen such that, if the galaxy image were circularly symmetric and if the formula were valid all radii, both large and small, then one-half of the total light of the system would be emitted interior to R e.

5. de Vaucouleurs R 1/4 law The Parameter I e is clearly the surface brightness at R=R e, and, according to the R 1/4 law, the central brightness of the galaxy is 10 3.33 I e ~2000 I e.

6. Box 4.1 Three-Parameter Fitting Function - generalized de Vaucouleurs law - Hubble-Oemler law - Hubble law Figure 4.27

7. de Vaucouleurs R 1/4 law To some extent the deviations of galaxies from the R1/4 law depend systematically on the galaxies’ luminosities.

8. cD galaxies

9. Galaxies whose surface-brightness profiles turn strongly upwards in a plot are called cD galaxies.

10. Dwarf elliptical galaxies Two classes Fig 4.30

11. Compact dwarf elliptical

12. Centers of elliptical galaxies Fig 4.31 Fig 4.32