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

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.

5 pages, 2 figures, to appear in Young Massive Star Clusters, eds. E. Perez, R. de Grijs, R. Gonzalez Delgado

References in corpus (3)

• Extragalactic Globular Clusters and Galaxy Formation
• Near-Infrared Observations of Globular Clusters in NGC 4472, NGC 4594, NGC 3585 and NGC 5813 and Implications for their Ages and Metallicities
• Young Globular Clusters in an old S0: Clues to the Formation History of NGC 4570

Cited by in corpus (3)

• Photometric Redshifts for Hyper Suprime-Cam Subaru Strategic Program Data Release 1
• The Next Generation Virgo cluster Survey (NGVS). XXVI. The issues of photometric age and metallicity estimates for globular clusters
• Star Cluster Formation and Star Formation: The Role of Environment and Star Formation Efficiencies