Detecting metal-rich intermediate-age Globular Clusters in NGC 4570 using K-band photometry

R. Kotulla; U. Fritze; P. Anders

doi:10.1007/s10509-009-0093-8

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arXiv · 0801.2318

Detecting metal-rich intermediate-age Globular Clusters in NGC 4570 using K-band photometry

R. Kotulla·U. Fritze·P. Anders

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Abstract

Globular Cluster Systems (GCSs) of most early-type galaxies feature two peaks in their optical colour distributions. Blue-peak GCs are believed to be old and metal-poor, whereas the ages, metallicities, and the origin of the red-peak GCs are still being debated. We obtained deep K-band photometry and combined it with HST observations in g and z to yield a full SED from optical to near-infrared. This now allows us to break the age-metallicity degeneracy. We used our evolutionary synthesis models GALEV for star clusters to compute a large grid of models with different metallicities and a wide range of ages. Comparing these models to our observations revealed a large population of intermediate-age (1-3 Gyr) and metalrich (~ solar metallicity) globular clusters, that will give us further insights into the formation history of this galaxy.

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R. Kotulla, U. Fritze, P. Anders. 2008-01-15. Detecting metal-rich intermediate-age Globular Clusters in NGC 4570 using K-band photometry. https://doi.org/10.1007/s10509-009-0093-8

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