LARGE-SCALE PHOTOGRAPHIC SURVEY OF FORNAX

Two pairs of CTIO 4 m prime-focus plates, measured by the APM, are used to investigate the structure of Fornax and its globular clusters. The surface distribution of stars reveals that the inner isopleths of Fornax are asymmetric. The position of highest density corresponds to cluster 4, 3' off from the geometrical center. Core and tidal radii (r(c),r(t)) are determined for the five globular clusters and for Fornax itself. Estimates of the r(c),r(t) for Fornax confirm the recent results of Irwin and Hatzidimitriou [ASP Conf. Ser., 48, 322 (1993)]. A global color-magnitude diagram reveals a well defined red clump and a weak blue horizontal branch. The oldest stars represent barely 4% of the Fornax populations. There is a slight indication that these older stars are more concentrated near the center than the bulk of Fornax. The age of the bulk of Fornax is found to be similar to 2 Gyr when applying the d(B-R) parameter of Hatzidimitriou [MNRAS, 251, 545 (1991)]. From a comparison of the number of giants in Fornax and in M3 we derive a M(upsilon) = -13.1 for Fornax.