Chapter 6. The Distribution of Baryons in the Universe

6.1. Extragalactic Backgrounds

6.1.1. The Radio Background

6.1.2. The Infrared Background

6.1.3. The UV Background

6.1.4. The X-ray Background

6.1.5. The Gamma Ray Background

6.1.6. A Possible Decaying Particle Background

6.2. The Space Density of Galaxies

6.2.1. The Luminosity Function of Galaxies

6.2.2. Deep Galaxy Counts: The Mystery of the Faint Blue Galaxies

6.2.3. A New Population of Galaxies at z = 0

6.3. Surface Brightness Selection Effects

6.3.1. Diameter Limited catalogs

6.3.2. Flux Limited Catalogs

6.4. Discovering Low Surface Brightness Galaxies

6.4.1. The Space Density of Galaxies as a Function of surface brightness

6.4.2. The Properties of LSB Galaxies

6.4.3. Cosmological Relevance of Low Surface Brightness Galaxies

6.5. Summary