Thursday, 18th May at 2.00pm @ the JAC
Maren Hempel
Michigan State University
"Globular Cluster Populations in Early-Type Galaxies"
ABSTRACT:
The formation and evolution of early-type galaxies is still under
debate, the wealth of available data drawing a more and more diverse
picture. In order to assign the underlying formation scenario to a
given galaxy we need to know the age structure of the stellar content.
We have developed a semi-numerical method to probe the age structure
in globular cluster systems, based on combined optical and
near-infrared photometry. The goal is to detect possible age
populations, to set some constraints on the relative age and size, and
if possible, find correlations between the age structure and various
galaxy parameters, e.g. environment, size and color. Here we present
the results for early-type galaxies found in clusters/groups as well
as for rather isolated galaxies, which so far revealed the coexistence
of age-subpopulation in three early-type galaxies. The study is based
on the determination of the cumulative age distribution in the
observed and in simulated globular cluster systems with a known age
structure.
Relevant publications:
Extragalactic Globular
Clusters in the Near Infrared: IV. Quantifying the Age Structure using
Monte-Carlo Simulations, Hempel & Kissler-Patig, 2004, A&A, 419, 863
The Ages of Globular Clusters in NGC 4365 Revisited with Deep HST
Observations,
Kundu et al., 2005, ApJ, 634, L41
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