We present the results of a Keck/DEIMOS survey of Ultra Compact Dwarfs ( UCDs ) in the Perseus Cluster core .
We confirm cluster membership for 14 UCDs , with radial velocities \sim 5300 km s ^ { -1 } .
Two of these confirmed Perseus UCDs have extremely blue colours ( B - R < 0.6 mag ) , reside in star forming filaments surrounding NGC 1275 , and have likely formed as massive star clusters in the last \sim 100 Myr .
We also measure a central velocity dispersion of a third , UCD13 ( \sigma _ { 0 } = 38 \pm 8 km s ^ { -1 } ) , the most extended UCD in our sample .
We determine it to have radius R _ { e } = 85 \pm 1.1 pc , a dynamical mass of ( 2.3 \pm 0.8 ) \times 10 ^ { 8 } M _ { \sun } , and a metallicity [ Z/H ] = -0.52 ^ { +0.33 } _ { -0.29 } dex .
UCD13 and the cluster ’ s central galaxy , NGC 1275 , have a projected separation of 30 kpc and a radial velocity difference of \sim 20 km s ^ { -1 } .
Based on its size , red colour , internal velocity dispersion , dynamical mass , metallicity and proximity to NGC 1275 , we argue that UCD13 is likely the remnant nucleus of a tidally stripped dE , with this progenitor dE having M _ { B } \approx - 16 mag and mass \sim 10 ^ { 9 } M _ { \odot } .