AAS 195th Meeting, January 2000
Session 129. Formation and Distribution of Galaxies
Oral, Saturday, January 15, 2000, 2:00-3:30pm, Regency VI

## [129.03] The Space Density of Galaxies in the Local Universe

K. O'Neil (Arecibo Observatory), G. D. Bothun (University of Oregon)

Using the catalog of O'Neil, Bothun, & Schombert (1999), we examine the central surface brightness distribution (\phi(\muB(0))) of galaxies in the 22.0 \leq \muB(0) \leq 25.0 mag arcsec-2 range. Taking advantage of having a catalog in which each galaxy has a known central surface brightness, scale length, and redshift, we apply a bi-variate volume correction to the data and extend the surface brightness distribution function by one magnitude, to 25.0 B mag arcsec-2. The result is a flat (slope = 0) surface brightness distribution function from the Freeman value of 21.65 ± 0.30 to the survey limit of 25.0 mag arcsec-2, more than 11\sigma away. This indicates that a significant percentage of the baryonic content of the universe is likely in potentials only dimly lit by the embedded galaxy.