TY - JOUR
T1 - The search for multiple populations in Magellanic Cloud Clusters - III. No evidence for multiple populations in the SMC cluster NGC 419
AU - Martocchia, S.
AU - Bastian, N.
AU - Usher, C.
AU - Kozhurina-Platais, V.
AU - Niederhofer, F.
AU - Cabrera-Ziri, I.
AU - Dalessandro, E.
AU - Hollyhead, K.
AU - Kacharov, N.
AU - Lardo, C.
AU - Larsen, S.
AU - Mucciarelli, A.
AU - Platais, I.
AU - Salaris, M.
AU - Cordero, M.
AU - Geisler, D.
AU - Hilker, M.
AU - Li, C.
AU - Mackey, D.
N1 - Publisher Copyright:
© 2017 The Authors
PY - 2017/7/1
Y1 - 2017/7/1
N2 - We present the third paper about our ongoing Hubble Space Telescope survey for the search for multiple stellar populations (MPs) within Magellanic Cloud clusters. We report here the analysis of NGC 419, an ∼1.5 Gyr old, massive (≾2 × 105 M☉) star cluster in the Small Magellanic Cloud (SMC). By comparing our photometric data with stellar isochrones, we set a limit on [N/Fe] enhancement of ≾+0.5 dex and hence we find that no MPs are detected in this cluster. This is surprising because in the first two papers of this series, we found evidence for MPs in four other SMC clusters (NGC 121; Lindsay 1, NGC 339, NGC 416), aged from 6 Gyr up to ∼10-11 Gyr. This finding raises the question whether age could play a major role in the MPs phenomenon. Additionally, our results appear to exclude mass or environment as the only key factors regulating the existence of a chemical enrichment, since all clusters studied so far in this survey are equally massive (∼1-2 × 105 M☉) and no particular patterns are found when looking at their spatial distribution in the SMC.
AB - We present the third paper about our ongoing Hubble Space Telescope survey for the search for multiple stellar populations (MPs) within Magellanic Cloud clusters. We report here the analysis of NGC 419, an ∼1.5 Gyr old, massive (≾2 × 105 M☉) star cluster in the Small Magellanic Cloud (SMC). By comparing our photometric data with stellar isochrones, we set a limit on [N/Fe] enhancement of ≾+0.5 dex and hence we find that no MPs are detected in this cluster. This is surprising because in the first two papers of this series, we found evidence for MPs in four other SMC clusters (NGC 121; Lindsay 1, NGC 339, NGC 416), aged from 6 Gyr up to ∼10-11 Gyr. This finding raises the question whether age could play a major role in the MPs phenomenon. Additionally, our results appear to exclude mass or environment as the only key factors regulating the existence of a chemical enrichment, since all clusters studied so far in this survey are equally massive (∼1-2 × 105 M☉) and no particular patterns are found when looking at their spatial distribution in the SMC.
KW - Galaxies: individual: SMC
KW - Galaxies: star clusters: individual: NGC 419
KW - Hertzsprung
KW - Magnitude diagrams
KW - Russell and colour
KW - Stars: abundances
UR - http://www.scopus.com/inward/record.url?scp=85034035834&partnerID=8YFLogxK
U2 - 10.1093/mnras/stx660
DO - 10.1093/mnras/stx660
M3 - Article
SN - 0035-8711
VL - 468
SP - 3150
EP - 3158
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -