|
Description
Using 3.6 and 4.5{mu}m images of 73 late-type, edge-on galaxies from the S^4^G survey, we compare the richness of the globular cluster populations of these galaxies to those of early-type galaxies that we measured previously. In general, the galaxies presented here fill in the distribution for galaxies with lower stellar mass, M_*_, specifically log(M_{star}_/M_{sun})<10, overlap the results for early-type galaxies of similar masses, and, by doing so, strengthen the case for a dependence of the number of globular clusters per 10^9^M_{sun}_ of galaxy stellar mass, T_N_, on M_*_. For 8.5<log(M_{star}_/M_{sun})<10.5 we find the relationship can be satisfactorily described as T_N_=(M_{star}_/10^6.7^)^-0.56^ when M_*_ is expressed in solar masses. The functional form of the relationship is only weakly constrained, and extrapolation outside this range is not advised. Our late-type galaxies, in contrast to our early types, do not show the tendency for low-mass galaxies to split into two T_N_ families. Using these results and a galaxy stellar mass function from the literature, we calculate that, in a volume-limited, local universe sample, clusters are most likely to be found around fairly massive galaxies (M_*_~10^10.8^M_{sun}_) and present a fitting function for the volume number density of clusters as a function of parent-galaxy stellar mass. We find no correlation between T_N_ and large-scale environment, but we do find a tendency for galaxies of fixed M_*_ to have larger T_N_ if they have converted a larger proportion of their baryons into stars.
|
