The ages and metallicities of the globular clusters in the Fornax dwarf spheroidal galaxy

Abstract

view Abstract Citations (40) References (47) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The ages and metallicities of the globular clusters in the Fornax dwarf spheroidal galaxy Zinn, R. ; Persson, S. E. Abstract The ages and metallicities of the four brightest clusters (2, 3, 4, and 5) in the Fornax dwarf spherical galaxy are estimated from new optical and near-infrared photometry and optical spectroscopy of their integrated light. The Fornax clusters are shown to have ages not less than 10 to the 10th years, and are ranked 3, 5, 2, and 4 in order of increasing metal abundance. Cluster 3 appears to be more metal poor than the galactic globular cluster M15, while cluster 4 appears to be slightly more metal rich than the galactic globulars NGC 1261 and NGC 1851; clusters 3 and 4 differ in metallicity by a factor of ten. Near-infrared data confirm that the J-K, H-K, and V-K colors of cluster 2 are too red for its visual colors, because it contains carbon stars. Excess light in the near-infrared is explained by the presence of only one carbon star, similar to those in the general field of Fornax, within 15 sec of its center; this carbon star is believed to be a superposed member of the field carbon star population. The metallicity range and ages of the Fornax clusters are similar to those of the oldest star clusters in the Magellanic Clouds and the globular clusters in the outer halo of the Galaxy. Publication: The Astrophysical Journal Pub Date: August 1981 DOI: 10.1086/159095 Bibcode: 1981ApJ...247..849Z Keywords: Astronomical Spectroscopy; Galactic Evolution; Galactic Structure; Globular Clusters; Infrared Astronomy; Metallic Stars; Astronomical Photometry; Hertzsprung-Russell Diagram; Infrared Photometry; Magellanic Clouds; Near Infrared Radiation; Red Giant Stars; Astrophysics full text sources ADS | data products NED (5)