Spectroscopic detection of multiple populations in the similar to 2 Gyr old cluster Hodge 6 in the LMC

We report the spectroscopic discovery of abundance spreads (i.e. multiple populations) in the similar to 2 Gyr old cluster in the LMC, Hodge 6. We use low-resolution VLT FORS2 spectra of 15 member stars in the cluster to measure their CN and CH band strengths at similar or equal to 3883 and 4300 angstrom, respectively, as well as [C/Fe] and [N/Fe] abundances. We find a subpopulation of two stars that are enriched in nitrogen, and we conclude that this subpopulation is evidence of multiple populations in Hodge 6. This is the second similar to 2 Gyr old cluster (the first being NGC 1978 in the LMC) to show multiple populations and the first spectroscopic detection of MPs in a cluster of this age. This result is interesting as it hints at a possible relationship between the disappearance of extended main sequence turn-offs in clusters younger than similar to 2 Gyr and the onset of multiple populations at similar to 2 Gyr, which should be explored further.


Published in:
Monthly Notices Of The Royal Astronomical Society, 484, 4, 4718-4725
Year:
Apr 01 2019
Publisher:
Oxford, OXFORD UNIV PRESS
ISSN:
0035-8711
1365-2966
Keywords:
Laboratories:




 Record created 2019-06-18, last modified 2019-06-25


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