We have determined the composite luminosity function ( LF ) for galaxies in 60 clusters from the 2dF Galaxy Redshift Survey .
The LF spans the range -22.5 < M _ { b _ { J } } < -15 , and is well-fitted by a Schechter function with { M _ { b _ { J } } } ^ { * } = -20.07 \pm 0.07 and \alpha = -1.28 \pm 0.03 ( H _ { 0 } =100 km s ^ { -1 } Mpc ^ { -1 } , \Omega _ { M } =0.3 , \Omega _ { \Lambda } =0.7 ) .
It differs significantly from the field LF of ( 35 ) , having a characteristic magnitude that is approximately 0.3 mag brighter and a faint-end slope that is approximately 0.1 steeper .
There is no evidence for variations in the LF across a wide range of cluster properties : the LF is similar for clusters with high and low velocity dispersions , for rich and poor clusters , for clusters with different Bautz-Morgan types , and for clusters with and without substructure .
The core regions of clusters differ from the outer parts , however , in having an excess of very bright galaxies .
We also construct the LFs for early ( quiescent ) , intermediate and late ( star-forming ) spectral types .
We find that , as in the field , the LFs of earlier-type galaxies have brighter characteristic magnitudes and shallower faint-end slopes .
However the LF of early-type galaxies in clusters is both brighter and steeper than its field counterpart , although the LF of late-type galaxies is very similar .
The trend of faint-end slope with spectral type is therefore much less pronounced in clusters than in the field , explaining why variations in the mixture of types do not lead to significant differences in the cluster LFs .
The differences between the field and cluster LFs for the various spectral types can be qualitatively explained by the suppression of star formation in the dense cluster environment , together with mergers to produce the brightest early-type galaxies . Key words : galaxies : luminosity function , mass function – galaxies : formation