Gemini Spectroscopy of Ultra-Compact Dwarfs in the Fossil Group NGC 1132
  A spectroscopic follow up of Ultra-Compact Dwarf (UCD) candidates in the
fossil group NGC 1132 is undertaken with the Gemini Multi Object Spectrograph
(GMOS). These new Gemini spectra prove the presence of six UCDs in the fossil
group NGC 1132 at a distance of D~100 Mpc and a recessional velocity of v_r =
6935 +/- 11 km/s. The brightest and largest member of the UCD population is an
M32 analog with a size of 77.1 pc and a magnitude of M_V=-14.8 mag with the
characteristics in between those of the brightest UCDs and compact elliptical
galaxies. The ensemble of UCDs have an average radial velocity of <v_r> = 6966
+/- 208 km/s and a velocity dispersion of sigma_v = 169 +/-18 km/s similar to
the one of poor galaxy groups. This work shows that UCDs can be used as test
particles to determine the dynamical properties of galaxy groups. The presence
of UCDs in the fossil group environment is confirmed and thus the fact that
UCDs can form across diverse evolutionary conditions.
