LARGE-SCALE PHOTOGRAPHIC SURVEY OF FORNAX

Two pairs of CTIO 4 m prime-focus plates, measured by the APM, are use d to investigate the structure of Fornax and its globular clusters. Th e surface distribution of stars reveals that the inner isopleths of Fo rnax are asymmetric. The position of highest density corresponds to cl uster 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 i tself. Estimates of the r(c),r(t) for Fornax confirm the recent result s of Irwin and Hatzidimitriou [ASP Conf. Ser., 48, 322 (1993)]. A glob al color-magnitude diagram reveals a well defined red clump and a weak blue horizontal branch. The oldest stars represent barely 4% of the F ornax populations. There is a slight indication that these older stars are more concentrated near the center than the bulk of Fornax. The ag e 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.