The central region of the Fornax cluster I. A catalog and photometric properties of galaxies in selected CCD fields

We present a photometric catalog (based on V and I photometry) of galaxies in the central regions of the Fornax galaxy cluster. Our 11 CCD fields cove r 0.17 square degrees in total. The limiting surface brightness is around 2 4 mag arcsec(-2), similar to that of Ferguson's (1989) catalog, whereas our limiting total magnitude is around V similar or equal to 22 mag, about two magnitudes fainter. It is the surface brightness limit, however. that prev ents us from detecting the counterparts of the faintest Local Group dwarf s pheroidals. The photometric properties of all objects are presented as a ca talog (Appendix A)(1). The properties and fit parameters of the surface bri ghtness profiles for a sub-sample are presented as a second catalog (Append ix B)(1). We can only add 4 new dwarf galaxies to Ferguson's catalog. However, we con firm that the dwarf galaxies in Fornax follow a similar surface brightness - magnitude relation as the Local Group dwarfs. They also follow the color (metallicity) - magnitude relation seen in other galaxy clusters. A formerl y suspected excess of dwarf galaxies surrounding the central giant cD galax y NGC 1399 can finally be ruled out. An enhanced density of objects around NGC 1399 can indeed be seen, but it a ppears displaced With respect to the central galaxy and is identified as a background cluster at z = 0.11 in Paper II of these series, which will disc uss spectroscopic results for our sample.