A search for ultra-compact dwarf galaxies in the Centaurus galaxy cluster

Abstract

Aims. Our aim is to extend the investigations of ultra-compact dwarf galaxies (UCD) beyond the well studied Fornax and Virgo clusters. Methods. We measured spectroscopic redshifts of about 400 compact object candidates with 19.2 < V < 22.4 mag in the central region of the Centaurus galaxy cluster (d = 43 Mpc), using 3 pointings with VIMOS@VLT. The luminosity range of the candidates covers the bright end of the globular cluster (GC) luminosity function and the luminosity regime of UCDs in Fornax and Virgo. Within the area surveyed, our completeness in terms of slit allocation is ≈30%. Results. We find 27 compact objects with radial velocities consistent with them being members of Centaurus, covering an absolute magnitude range -12.2 < M v