EDP Sciences
Free access
Volume 485, Number 1, July I 2008
Page(s) 71 - 80
Section Galactic structure, stellar clusters, and populations
DOI http://dx.doi.org/10.1051/0004-6361:20079298
Published online 06 May 2008

A&A 485, 71-80 (2008)
DOI: 10.1051/0004-6361:20079298

Structures in surface-brightness profiles of LMC and SMC star clusters: evidence of mergers?

L. Carvalho1, T. A. Saurin1, E. Bica1, C. Bonatto1, and A. A. Schmidt2

1  Universidade Federal do Rio Grande do Sul, Departamento de Astronomia, CP 15051, RS, Porto Alegre 91501-970, Brazil
    e-mail: [luziane;bica;charles]@if.ufrgs.br; tiago.saurin@ufrgs.br
2  Universidade Federal de Santa Maria, LANA, RS, Santa Maria 97119-900, Brazil
    e-mail: alex@lana.ccne.ufsm.br

Received 20 December 2007 / Accepted 2 April 2008

Context. The LMC and SMC are rich in binary star clusters, and some mergers are expected. It is thus important to characterise single clusters, binary clusters and candidates for mergers.
Aims. We selected a sample of star clusters in each Cloud with this aim. Surface photometry of 25 SMC and 22 LMC star clusters was carried with the ESO Danish 1.54 m telescope. 23 clusters were observed for the first time for these purposes.
Methods. We fitted Elson, Fall and Freeman (EFF) profiles to the data, deriving structural parameters, luminosities and masses. We also use isophotal maps to constrain candidates for cluster interactions.
Results. The structural parameters, luminosities and masses presented good agreement with those in the literature. Three binary clusters in the sample have a double profile. Four clusters (NGC 376, K 50, K 54 and NGC 1810) do not have companions and present important deviations from EFF profiles.
Conclusions. The present sample contains blue and red Magellanic clusters. Profiles with excess with respect to EFF were detected in some blue clusters. We find evidence that important deviations from the body of EFF profiles might be used as a tool to detect cluster mergers.

Key words: galaxies: Magellanic Clouds -- galaxies: star clusters

© ESO 2008