Structural Parameters of Seven Small Magellanic Cloud Intermediate-Age and Old Star Clusters

Date

2009

Authors

Glatt, Katharina
Grebel, E K
Gallagher, John S
Nota, Antonella
Sabbi, Elena
Sirianni, Marco
Clementini, G
Da Costa, Gary
Tosi, Monica
Harbeck, Daniel

Journal Title

Journal ISSN

Volume Title

Publisher

University of Chicago Press

Abstract

We present structural parameters for the seven intermediate-age and old star clusters NGC121, Lindsay1, Kron3, NGC339, NGC416, Lindsay38, and NGC419 in the Small Magellanic Cloud (SMC). We fit King profiles and Elson, Fall, and Freeman profiles to both surface-brightness and star-count data taken with the Advanced Camera for Surveys aboard the Hubble Space Telescope. Clusters older than ∼ 1Gyr show a spread in cluster core radii that increases with age, while the youngest clusters have relatively compact cores. No evidence for post-core-collapse clusters was found. We find no correlation between core radius and distance from the SMC center, although consistent with other studies of dwarf galaxies, some relatively old and massive clusters have low densities. The oldest SMC star cluster, the only globular NGC121, is the most elliptical object of the studied clusters. No correlation is seen between ellipticity and distance from the SMC center. The structures of these massive intermediate-age (1-8 Gyr) SMC star clusters thus appear to primarily result from internal evolutionary processes.

Description

Keywords

Keywords: Galaxies; Star clusters Magellanic Clouds

Citation

Source

Astronomical Journal

Type

Journal article

Book Title

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Access Statement

License Rights

Restricted until

2037-12-31