We have undertaken a study of the globular cluster ( GC ) systems of a large sample of elliptical and spiral galaxies in order to test specific predictions of galaxy formation models .
Here we present results for the first elliptical in the study , the giant Virgo cluster galaxy NGC 4472 ( M49 ) .
The galaxy was observed in three filters ( BV R ) using the wide-field Mosaic Imager on the Kitt Peak 4-meter telescope .
The Mosaic images roughly double the radial coverage of previous CCD observations of NGC 4472 .
We have combined the Mosaic data with published spectroscopic data and archival HST observations in order to study NGC 4472 ’ s GC system in detail , and to fully characterize the amount of contamination in our sample of GC candidates .
We find that the radial profile of the GC system is fit fairly well by a de Vaucouleurs law of the form log \sigma _ { GC } = ( 3.38 \pm 0.08 ) - ( 1.56 \pm 0.05 ) r ^ { 1 / 4 } out to 17 \arcmin ( \sim 80 kpc ) , but that the observed profile falls slightly below the de Vaucouleurs law between 17 \arcmin and 23 \arcmin , the limit of the data .
The bimodal color distribution observed in previous studies is apparent in our data .
We find a small metallicity gradient in the inner 8 \arcmin of the total GC system due to the increasing ratio of blue to red clusters , consistent with results from past studies .
The gradient vanishes , however , when the entire radial extent of the data is taken into account .
We estimate a total of \sim 5,900 GCs in NGC 4472 out to 23 \arcmin , yielding a specific frequency of 3.6 \pm 0.6 within this radius .
This specific frequency value is smaller than that found by previous studies of NGC 4472 .
We examine the implications of these results with regard to predictions made by four different galaxy formation models , and find that all four models have at least one inconsistency with the data .