The Galaxy Luminosity Function at z</=0.05: Dependence on Color
Abstract
We examine the dependence of the galaxy luminosity function on color using a sample of 1513 galaxies from the Southern-Sky Redshift Survey (SSRS2). This subsample of the SSRS2 covers the range δ≤-17.5°, bII≤-4O°, 0≤ζ≤.05 and is based on B - R colors from the ESO-Uppsala Surface Photometry Catalog (Lauberts & Valentijn 1989). Our large sample allows us to measure the shapes of the color-dependent luminosity functions directly. The faint end of the luminosity function of blue galaxies (B26-RB26≤1.3) is significantly steeper than it is for red galaxies, confirming the results of Metcalfe et al. (1991). Using a complete, magnitude-limited subsample of 831 galaxies with B26≤14.5, we find that the luminosity functions are well fitted by Schechter functions with parameters M*=-19.43±O.23, α=-1.46±0.18 for blue galaxies and M*=-19.25±0.25, α=-0.73±0.24 for red galaxies. We also develop incompleteness corrections for the maximum-likelihood techniques of Sandage et al (1979) and Efstathiou et al (1988) and apply them to the deeper sample (B26≤15.5). Although the color dependence of the incompleteness is uncertain, the bluest quartile of the deeper sample has a luminosity function which is at least as steep as α=-1.35 (2σ lower limit) and may be as steep as α=-1.69.
- Publication:
-
The Astronomical Journal
- Pub Date:
- January 1997
- DOI:
- 10.1086/118243
- Bibcode:
- 1997AJ....113..185M
- Keywords:
-
- GALAXIES: LUMINOSITY FUNCTION;
- GALAXIES: EVOLUTION