IALP   13078
INSTITUTO DE ASTROFISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
The globular cluster system of NGC 1316. II - The extraordinary object SH2
Autor/es:
T. RICHTLER; B. KUMAR; L.P. BASSINO; B. DIRSCH; A. J. ROMANOWSKY
Revista:
ASTRONOMY AND ASTROPHYSICS
Editorial:
EDP SCIENCES S A
Referencias:
Lugar: Paris; Año: 2012 vol. 543 p. 1 - 4
ISSN:
0004-6361
Resumen:
Context. SH2 has been described as an isolated HII-region, located about 6.50 south of the nucleus of NGC 1316 (Fornax A), a merger remnant in the the outskirts of the Fornax cluster of galaxies.Aims. We give a first, preliminary description of the stellar content and environment of this remarkable object.Methods. We used photometric data in the Washington system and HST photometry from the Hubble Legacy Archive for a morphological description and preliminary aperture photometry. Low-resolution spectroscopy provides radial velocities of the brightest star cluster in SH2 and a nearby intermediate-age cluster.Results. SH2 is not a normal HII-region, ionized by very young stars. It contains a multitude of star clusters with ages of approximately 10^8 yr. A ring-like morphology is striking. SH2 seems to be connected to an intermediate-age massive globular cluster with a similar radial velocity, which itself is the main object of a group of fainter clusters. Metallicity estimates from emission lines remain ambiguous.Conclusions. The present data do not yet allow firm conclusions about the nature or origin of SH2. It might be a dwarf galaxy that has experienced a burst of extremely clustered star formation. We may witness how globular clusters are donated to a parent galaxy.