| Title | An Extended Star Cluster at the Outer Edge of the Spiral Galaxy M 33 |
| Authors | StonkutÄ, Rima; VanseviÄius, Vladas; Arimoto, Nobuo; Hasegawa, Takashi; Narbutis, Donatas; Tamura, Naoyuki; Jablonka, Pascale; Ohta, Kouji; Yamada, Yoshihiko |
| Bibcode | 2008AJ....135.1482S Search ADS ↗ |
| Abstract | We report the discovery of an extended globular-like star cluster, M 33-EC1, at the outer edge of the spiral galaxy M 33. The distance to the cluster is 890 kpc, and it lies at a projected distance of 12.5 kpc from the center of M 33. Old age (gsim7 Gyr) and low metallicity ([M/H] lsim 1.4) are estimated on the basis of isochrone fits. Color-magnitude diagrams of stars, located in the cluster's area, and photometric and structural parameters of the cluster are presented. The cluster's luminosity (MV = 6.6) and half-light radius (r h = 20.3 pc) are comparable to those of the extended globular clusters, discovered in more luminous Local Group galaxies, the Milky Way and M 31. Extended globular clusters are suspected to be remnants of accreted dwarf galaxies, and the finding of such a cluster in the late-type dwarf spiral galaxy M 33 would imply a complex merging history in the past. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. |
| Objects | 1 Objects Search NED ↙ |
