The Spatial Distribution of Globular Cluster Systems in Early-type Galaxies: Estimation Procedure and Catalog of Properties for Globular Cluster Systems Observed with Deep Imaging Surveys
Résumé
We present an analysis of the spatial distribution of globular cluster (GC) systems of 118 nearby early-type galaxies in the Next Generation Virgo Cluster Survey and Mass Assembly of early-Type GaLAxies with their fine Structures survey programs, which both used MegaCam on the Canada-France-Hawaii Telescope. We describe the procedure used to select GC candidates and fit the spatial distributions of GCs to a two-dimensional Sérsic function, which provides effective radii (half number radii) and Sérsic indices, and estimate background contamination by adding a constant term to the Sérsic function. In cases where a neighboring galaxy affects the estimation of the GC spatial distribution in the target galaxy, we fit two two-dimensional Sérsic functions, simultaneously. We also investigate the color distributions of GCs in our sample by using Gaussian mixture modeling. For GC systems with bimodal color distributions, we divide the GCs into blue and red subgroups and fit their respective spatial distributions with Sérsic functions. Finally, we measure the total number of GCs based on our fitted Sérsic function, and calculate the GC specific frequency.
Unified Astronomy Thesaurus concepts: Early-type galaxies (429); Virgo Cluster (1772); Globular star clusters (656); Field galaxies (533); Galaxy evolution (594) Materials only available in the online version of record: figure sets
Globular clusters (GCs) have long been used as probes of galaxy formation and evolution. While studies of GCs belonging to individual galaxies have provided many insights into galaxy evolution, it is the systematic study of GCs in large surveys (e.g.,
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Planète et Univers [physics]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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