We present the first survey of resolved stellar populations in the remote outer halo of our nearest giant elliptical ( gE ) , Centaurus A ( D = 3.8 Mpc ) .
Using the VIMOS/VLT optical camera , we obtained deep photometry for four fields along the major and minor axes at projected elliptical radii of \sim 30 - 85 kpc ( corresponding to \sim 5 - 14 R _ { eff } ) .
We use resolved star counts to map the spatial and colour distribution of red giant branch ( RGB ) stars down to \sim 2 magnitudes below the RGB tip .
We detect an extended halo out to the furthermost elliptical radius probed ( \sim 85 kpc or \sim 14 R _ { eff } ) , demonstrating the vast extent of this system .
We detect localised substructure in these parts , visible in both ( old ) RGB and ( intermediate-age ) luminous asymptotic giant branch stars , and there is some evidence that the outer halo becomes more elliptical and has a shallower surface brightness profile .
We derive photometric metallicity distribution functions for halo RGB stars and find relatively high median metallicity values ( < [ Fe/H ] > _ { med } \sim - 0.9 to -1.0 dex ) that change very little with radius over the extent of our survey .
Radial metallicity gradients are measured to be \approx - 0.002 - 0.004 dex/kpc and the fraction of metal-poor stars ( defined as [ Fe/H ] < -1.0 ) is \approx 40 - 50 % at all radii .
We discuss these findings in the context of galaxy formation models for the buildup of gE haloes .