Washington Photometry of the Globular Cluster System of NGC 4472. II. The Luminosity Function and Spatial Structure

We present a comprehensive study of the luminosity function and spatialstructure of the globular cluster system of NGC 4472, based on deep wide fieldWashington CT1 CCD images. The globular cluster luminosity function shows apeak at T1=23.3 +/- 0.1 mag, about 1.5 mags brighter than our 50% completenesslimit. We estimate the true distance modulus to NGC 4472 to be (m-M)o = 31.2+/- 0.2. With our large sample (~ 2000) of bright globular clusters over a widefield, we make a definitive investigation of the spatial structures of themetal-poor and metal-rich cluster populations and find that they aresystematically different: (1) The metal-rich clusters are more centrallyconcentrated than the metal-poor clusters; and (2) The metal-rich clusters areelongated roughly along the major axis of the parent galaxy, while themetal-poor clusters are essentially spherically distributed. In general, themetal-rich clusters closely follow the underlying halo starlight of NGC 4472 interms of spatial structure and metallicity, while the metal-poor clusters donot. The global value of the specific frequency of the globular clusters in NGC4472 is estimated to be S_N = 4.7 +/- 0.6. The local specific frequencyincreases linearly outward from the center of NGC 4472 until ~ 5'.5, beyondwhich it levels off at S_N ~ 8.5 until the limit of our data at 7'. Thespecific frequency of both the metal-rich and metal-poor populations showssimilar behavior. However, S_N of the metal-poor clusters is about a factor 2larger than that of the metal-rich clusters in the outer regions. Implicationsof these results for the origin of the globular clusters in NGC 4472 arediscussed.Comment: 28 Pages (AASLaTeX), 9 Postscript figures, Accepted for publicaion in the Astronomical Journal, Mar. 31st, 199