Abstract
We present the largest spectroscopic investigation of one of the faintest and least studied stellar clusters of the MilkyWay, ESO 452-SC11. Using the Anglo-Australian Telescope AAOmega and Keck High Resolution Echelle Spectrometer spectrographs we have identified 11 members of the cluster and found indications of star-to-star light element abundance variation, primarily using the blue cyanogen absorption features. From a stellar density profile, we estimate a total cluster mass of (6.8 +/- 3.4) x 10³M⊙. This would make ESO 452-SC11 the lowest mass cluster with evidence for multiple populations. These data were also used to measure the radial velocity of the cluster (16.7 +/- 0.3 kms¯¹) and confirm that ESO 452-SC11 is relatively metal rich for a globular cluster ([Fe/H]= -0.81 +/- 0.13). All known massive clusters studied in detail show multiple populations of stars each with a different chemical composition, but many low-mass globular clusters appear to be chemically homogeneous. ESO 452-SC11 sets a lower mass limit for the multiple stellar population phenomenon.
Original language | English |
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Pages (from-to) | 2856-2868 |
Number of pages | 13 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 472 |
Issue number | 3 |
DOIs | |
Publication status | Published - Dec 2017 |
Bibliographical note
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society, 472(3), pp.2856–2868. The original publication is available at https://doi.org/10.1093/mnras/stx2174. Copyright 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Keywords
- globular clusters: individual: ESO 452-SC11