Abstract

Deep R-band CFHT images for 8 dE,N and 3 dE galaxies in the Virgo Cluster have been used to search for globular cluster systems (GCSs) around these galaxies. Almost every galaxy studied shows an excess of stellar-like objects that indicate the presence of a GCS. The specific frequencies of the GCSs cover a wide range in values, but most appear to have S-N of about 3-8, which is similar to the range found in dEs in the Local Group, as well as in giant ellipticals. The mean values of S-N for dE and dE,N galaxies are similar within the errors, suggesting that they are basically similar types of objects, with minor differences due to environment. In addition, the dwarfs near M87 do not share the large S-N(similar to 15) of M87 itself. A few low-luminosity dEs do have high S-N values, which we attribute to significant gaseous mass loss at an early epoch. A mean value of [Fe/H]=-1.45+/-0.2 has been derived for the GCSs around the two dwarfs for which we have (C-T1) photometry, VCC 1254 and VCC 1386. These are 0.4 to 0.6 dex more metal-poor than the galaxy light, following the pattern observed in both giant and dwarf elliptical galaxies. The observed GC (and any possible fainter GCs that have since dissolved) could not have been wholly responsible for producing enough heavy element enrichment to create this metallicity offset; there must have been a large contribution of heavy elements from other early sites of star formation. The globular cluster luminosity function (GCLF) for the combined dataset shows a turnover at T1 similar or equal to R similar or equal to 23.6+/-0.3, only slightly fainter than in the Virgo giant galaxies. However, the corresponding mass spectrum has a slope of -1.9+/-0.5, similar to that found in both giant and dwarf galaxies. This is evidence that the general mechanism of globular cluster formation (formation from dense cores within supergiant molecular clouds) is similar in all types of galaxies. (C) 1996 American Astronomical Society.