Letter to the Editor
Intra-cluster globular clusters around NGC 1399 in Fornax? *
Universidad de Concepción, Departamento de Física, Casilla 160-C, Concepción, Chile
2 Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany e-mail: email@example.com
3 Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, 1900-La Plata, Argentina and IALP-CONICET
4 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
Accepted: 16 October 2007
Aims. We investigate whether the globular clusters (GCs) in the recently published sample of GCs in the Fornax cluster by Bergond and coworkers are indeed intra-cluster objects.
Methods.We combine their catalogue of radial velocity measurements with our CTIO MOSAIC photometry in the Washington system and analyse the relation of metal-poor and metal-rich GCs with their host galaxies.
Results.The metal-rich GCs appear to be kinematically associated with their respective host galaxies. The vast majority of the metal-poor GCs found in between the galaxies of the Fornax cluster have velocities that are consistent with their being members of the very extended NGC 1399 GC system. We find that when the sample is restricted to the most accurate velocity measurements, the GC velocity dispersion profile can be described with a mass model derived for the NGC 1399 GC system within 80 kpc. We identify one “vagrant” GC whose radial velocity suggests that it is not bound to any galaxy unless its orbit has a very large apogalactic distance.
Key words: galaxies: star clusters / galaxies: kinematics and dynamics / galaxies: elliptical and lenticular, cD / galaxies: clusters: individual: Fornax cluster / galaxies: individual: NGC 1399
© ESO, 2007