Chantereau, W, Salaris, M, Bastian, N and Martocchia, S (2019) Helium enrichment in intermediate-age Magellanic Clouds clusters: towards an ubiquity of multiple stellar populations? Monthly Notices of the Royal Astronomical Society, 484 (4). pp. 5236-5244. ISSN 0035-8711

Text Helium enrichment in intermediate-age Magellanic Clouds clusters towards an ubiquity of multiple stellar populations - Published Version Download (3MB)

Abstract

Intermediate-age star clusters in the Magellanic Clouds harbour signatures of the multiple stellar populations long thought to be restricted to old globular clusters. We compare synthetic horizontal branch models with Hubble Space Telescope photometry of clusters in the Magellanic Clouds, with age between ~2 and ~10 Gyr, namely NGC 121, Lindsay 1, NGC 339, NGC 416, Lindsay 38, Lindsay 113, Hodge 6 and NGC 1978. We find a clear signature of initial helium abundance spreads (delta(Y)) in four out of these eight clusters (NGC 121, Lindsay 1, NGC 339, NGC 416) and we quantify the value of delta(Y). For two clusters (Lindsay 38, Lindsay 113) we can only determine an upper limit for delta(Y), whilst for the two youngest clusters in our sample (Hodge 6 and NGC 1978) no conclusion about the existence of an initial He spread can be reached. Our delta(Y) estimates are consistent with the correlation between maximum He abundance spread and mass of the host cluster found in Galactic globular clusters. This result strengthens the emerging view that the formation of multiple stellar populations is a standard process in massive star clusters, not limited to a high redshift environment.

Item Type:	Article
Additional Information:	This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2019 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords:	0201 Astronomical and Space Sciences
Subjects:	Q Science > QB Astronomy Q Science > QC Physics
Divisions:	Astrophysics Research Institute
Publisher:	Oxford University Press
Related URLs:	http://arxiv.org/abs/1902.01806v1
Date Deposited:	19 Feb 2019 12:26
Last Modified:	04 Sep 2021 01:58
DOI or ID number:	10.1093/mnras/stz378
URI:	https://researchonline.ljmu.ac.uk/id/eprint/10187

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