Intermediate-age Globular Clusters in Four Galaxy Merger Remnants

Abstract

We present the results of combining Hubble Space Telescope optical photometry with ground-based Ks-band photometry from the Gemini imagers NIRI and FLAMINGOS-I to study the globular-cluster populations in four early-type galaxies that are candidate remnants of recent mergers (NGC1700, NGC2865, NGC4382, and NGC7727). These galaxies were chosen based on their blue colors and fine structure, such as shells and ripples that are indicative of past interactions. We fit the combined VIKs globular-cluster data with simple toy models of mixed cluster populations that contain three subpopulations of different age and metallicity. The fits, done via Chi-square mapping of the parameter space, yield clear evidence for the presence of intermediate-age clusters in each galaxy. We find that the ages of 1-2 Gyr for these globular-cluster subpopulations are consistent with the previously estimated merger ages for the host galaxies.

11 pages, 12 figures and 4 tables

References in corpus (3)

• The GALEX UV emission in shell galaxies: tracing galaxy "rejuvenation" episodes
• Globular cluster systems of six shell galaxies
• X-ray observations of three young, early-type galaxies

Cited by in corpus (4)

• Isolated ellipticals and their globular cluster systems III. NGC 2271, NGC 2865, NGC 3962, NGC 4240 and IC 4889
• Globular Clusters As Tracers of Fine Structure in the Dramatic Shell Galaxy NGC 474
• A Wide-field Photometric Survey of Globular Clusters in the Peculiar Early-type Galaxy M85
• Star formation in low density HI gas around the Elliptical Galaxy NGC2865