Abstract

The two brightest elliptical galaxies in the Eridanus A group, NGC 1400 and NGC 1407, have been observed in both the Washington T-1 and Kron-Cousins I filters to obtain photometry of their globular cluster systems (GCSs). This group of galaxies is of particular interest due to its exceptionally high M/L value, previously estimated at similar to 3000h, making this cluster highly dark-matter-dominated [Gould, ApJ. 403, 37 (1993)]. NGC 1400's radial velocity (549 km/s) is extremely low compared to that of the central galaxy of Eridanus A (NGC 1407 with upsilon(circle dot)=1766 km/s) and the other members of the system, suggesting that it is a foreground galaxy projected by chance onto the cluster. Using the shapes of the globular cluster luminosity functions, however, we derive distances of 17.6+/-3.1 Mpc to NGC 1407 and 25.4+/-7.0 Mpc to NGC 1400. These results support earlier conclusions that NGC 1400 is at the distance of Eridanus A and therefore has a large peculiar velocity. Specific frequencies are also derived for these galaxies, yielding values of S-N=4.0+/-1.3 for NGC 1407 and S-N=5.2+/-2.0 for NGC 1400. In this and other respects, these two galaxies have GCSs which are consistent with those observed in other galaxies. (C) 1997 American Astronomical Society.