The VMC survey - XV. The Small Magellanic Cloud--Bridge connection history as traced by their star cluster populations

A.E. PIATTI; R. DE GRIJS, S. RUBELE, M.R. CIONI, V. RIPEPI, L. KERBER

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 450 p. 552 - 563

0035-8711

We present results based on Y JKs photometry of star clusters located in the outer-most, eastern region of the Small Magellanic Cloud (SMC). We analysed a total of 51catalogued clusters whose colour{magnitude diagrams (CMDs), having been cleanedfrom eld-star contamination, were used to assess the clusters´ reality and estimateages of the genuine systems. Based on CMD analysis, 15 catalogued clusters were foundto be possible non-genuine aggregates. We investigated the properties of 80% of thecatalogued clusters in this part of the SMC by enlarging our sample with previouslyobtained cluster ages, adopting a homogeneous scale for all. Their spatial distributionsuggests that the oldest clusters, log(t yr􀀀1) > 9.6, are in general located at greaterdistances to the galaxy´s centre than their younger counterparts { 9.0 6 log(t yr􀀀1)6 9.4 { while two excesses of clusters are seen at log(t yr􀀀1) 9.2 and log(t yr􀀀1) 9.7. We found a trail of younger clusters which follow the Wing/Bridge components.This long spatial sequence does not only harbour very young clusters, log(t yr􀀀1) 7.3, but it also hosts some of intermediate ages, log(t yr􀀀1) 9.1. The derived clusterand eld-star formation frequencies as a function of age are dierent. The mostsurprising feature is an observed excess of clusters with ages of log(t yr􀀀1) < 9.0,which could have been induced by interactions with the LMC.