We present wide-field multiband photometry of globular cluster ( GC ) systems in NGC 1399 , NGC 1404 , and NGC 1387 located at the central region of the Fornax galaxy cluster .
Observation was carried out through U , B , V , and I bands , which marks one of the widest and deepest U -band studies on extragalactic GC systems .
The present U -band photometry enables us to significantly reduce the contamination by a factor of two for faint sources ( V _ { 0 } \sim 23.5 ) .
The main results based on some 2000 GC candidates around NGC 1399 , NGC 1404 , and NGC 1387 are as follows : ( 1 ) the GC system in each galaxy exhibits bimodal color distributions in all colors examined , but the shape of color histograms varies systematically depending on colors ; ( 2 ) NGC 1399 shows that the mean colors of both blue and red GCs become bluer with increasing galactocentric radius ; ( 3 ) NGC 1399 shows overabundance of GCs in the directions of NGC 1404 and NGC 1387 , indicating their ongoing interactions ; and ( 4 ) NGC 1399 also exhibits a \sim 0 \farcm 5 offset between the center of the inner GC distribution and the galaxy ’ s optical center , suggesting that NGC 1399 is not yet dynamically relaxed and may be undergoing merger events .