2.1.2. The Mean Luminosity Density
Recent measurements of the mean luminosity density contributed by
high surface brightness galaxies at moderately low
redshift are summarized in Table 2. There is a
substantial spread of estimates of the parameters
* and
M* in the Schechter function,
but the total luminosity density,
= * L* 
(
+ 2), is better
defined:
most values are in the range
B =
(1.8-2.2) x 108h L
Mpc-3.
The exception is the significantly lower number from the APM-Stromlo
survey
(Loveday et al. 1992).
We adopt
The second expression is the corresponding value of the
mass-to-light ratio in the Einstein-de Sitter model.
Luminosity Function
Parameters
*
(B)
Author
M*(B)
(0.01 h3 Mpc-3)
(108 h L Mpc-3)
Efstathiou et
al. (1988)
-19.68 -1.1 1.56 1.93
Loveday et al. (1992)
-19.50 -0.97 1.40 1.35
da Costa et al. (1994)
-19.5 -1.20 1.5 1.71
Marzke et al. (1994)
-18.8 -1.0 4.0
2.1
Lilly et al. (1995)
-19.36 -1.03 2.48
2.18
Ellis et al. (1996)
-19.20 -1.09 2.6
2.05
Zucca et al. (1997)
-19.61 -1.22 2.0
2.2