An optical/NIR survey of globular clusters in early-type galaxies. I. Introduction and data reduction procedures
Abstract
Context: The combination of optical and near-infrared (NIR) colours has the potential to break the age/metallicity degeneracy and offers a better metallicity sensitivity than optical colours alone. Previous studies of extragalactic globular clusters (GCs) with this colour combination, however, have suffered from small samples or have been restricted to a few galaxies. Aims: We compile a homogeneous and representative sample of GC systems with multi-band photometry to be used in subsequent papers where ages and metallicity distributions will be studied. Methods: We acquired deep K-band images of 14 bright nearby early-type galaxies. The images were obtained with the LIRIS near-infrared spectrograph and imager at the William Herschel Telescope (WHT) and combined with optical ACS g and z images from the Hubble Space Telescope public archive. Results: For the first time GC photometry of 14 galaxies are observed and reduced homogeneously in this wavelength regime. We achieved a limiting magnitude of K~20-21. For the majority of the galaxies we detect about 70 GCs each. NGC4486 and NGC4649, the cluster-richest galaxies in the sample contain 301 and 167 GCs, respectively. We present tables containing coordinates, photometry and sizes of the GCs available.
Keywords
Cite
@article{arxiv.1010.0687,
title = {An optical/NIR survey of globular clusters in early-type galaxies. I. Introduction and data reduction procedures},
author = {A. L. Chies-Santos and S. S. Larsen and E. M. Wehner and H. Kuntschner and J. Strader and J. P. Brodie},
journal= {arXiv preprint arXiv:1010.0687},
year = {2015}
}
Comments
A&A accepted, 18 pages, 13 figures