We present wide-field Keck telescope imaging of the globular cluster ( GC ) systems around NGC 1407 and NGC 1400 in the Eridanus galaxy cloud .
This is complemented by Hubble Space Telescope images from the Advanced Camera for Surveys of NGC 1407 and Wide Field and Planetary Camera 2 images of NGC 1400 .
We clearly detect bimodality in the GC colour distribution of NGC 1407 .
The blue GC subpopulation has a mean colour of B - I = 1.61 and a relative contribution of around 40 % , whereas the red subpopulation with B - I = 2.06 contributes 60 % to the overall GC system .
Assuming old ages , this corresponds to [ Fe/H ] = –1.45 and –0.19 .
Both subpopulations are intrinsically broad in colour ( indicating a range in ages and/or metallicities ) , with the red subpopulation being broader than the blue .
The GC colour distribution for NGC 1400 is less clear cut than for NGC 1407 , however , we also find evidence for a bimodal distribution .
We find the NGC 1407 red GCs to be 20 % smaller in size than the blue ones .
This is consistent with the expectations of mass segregation in an old coeval GC system .
Half a dozen large objects ( 20–40 pc ) , with GC-like colours are identified , which are probably background galaxies .

The HST data sets allow us to probe to small galactocentric radii .
Here we find both GC systems to possess a GC surface density distribution which is largely constant in these inner galaxy regions .
We fit isothermal-like profiles and derive GC system core radii of 9.4 kpc for NGC 1407 and 5.8 kpc for NGC 1400 .
For NGC 1407 we are able to separate the surface density distribution into blue and red subpopulations , giving 17.8 and 7.6 kpc respectively .
Outside this central region , the radial profile of the GC surface density is similar to that of the galaxy light for NGC 1407 but it is flatter for NGC 1400 .
The mean GC magnitude appears to be constant with galactocentric radius .
We find that for both galaxies , the GC systems have a similar ellipticity and azimuthal distribution as the underlying galaxy starlight .
A fit to the GC luminosity function gives a distance modulus of 31.6 , which is in good agreement with distances based on the Faber-Jackson relation and the Virgo infall corrected velocity .
This distance lies at the midpoint of recent surface brightness fluctuation distance measurements .