The search for multiple populations in Magellanic Clouds clusters – V. Correlation between cluster age and abundance spreads

ABSTRACT In our HST photometric survey, we have been searching for multiple stellar populations (MPs) in Magellanic Clouds (MCs) massive star clusters which span a significant range of ages (∼1.5–11 Gyr). In the previous papers of the series, we have shown that the age of the cluster represents one of the key factors in shaping the origin of the chemical anomalies. Here, we present the analysis of four additional clusters in the MCs, namely Lindsay 38, Lindsay 113, NGC 2121, and NGC 2155, for which we recently obtained new UV HST observations. These clusters are more massive than ∼104 M⊙ and have ages between ∼2.5 and ∼6 Gyr, i.e. located in a previously unexplored region of the cluster age/mass diagram. We found chemical anomalies, in the form of N spreads, in three out of four clusters in the sample, namely in NGC 2121, NGC 2155, and Lindsay 113. By combining data from our survey and HST photometry for three additional clusters in the Milky Way (namely 47 Tuc, M15, and NGC 2419), we show that the extent of the MPs in the form of N spread is a strong function of age, with older clusters having larger N spreads with respect to the younger ones. Hence, we confirm that cluster age plays a significant role in the onset of MPs.

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Star Clusters in the Magellanic Clouds

Symposium - International Astronomical Union ◽

10.1017/s0074180900118406 ◽

1999 ◽

Vol 190 ◽

pp. 397-404 ◽

Cited By ~ 7

Author(s):

G. S. Da Costa

Keyword(s):

Star Formation ◽

Globular Clusters ◽

Star Clusters ◽

Magellanic Clouds ◽

Field Star ◽

Age Gap ◽

Significant Change ◽

New Evidence ◽

Cluster Age

Recent results for the old and intermediate-age star clusters of the Magellanic Clouds are reviewed. Highlights include new evidence that the LMC old clusters are as old the Galaxy's halo globular clusters and the persistence of the LMC cluster “Age Gap” despite field star evidence for significant star formation during the cluster age gap epoch. For the SMC new data confirm the lack of significant change in cluster abundances with age prior to ~4 Gyr ago.

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Black Holes and Core Expansion in Massive Star Clusters

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308015548 ◽

2007 ◽

Vol 3 (S246) ◽

pp. 176-180

Author(s):

A. D. Mackey ◽

M. I. Wilkinson ◽

M. B. Davies ◽

G. F. Gilmore

Keyword(s):

Black Holes ◽

Stellar Evolution ◽

Massive Star ◽

Massive Stars ◽

Star Clusters ◽

Magellanic Clouds ◽

Core Radius ◽

Stellar Component ◽

Rapid Mass ◽

Dynamical Origin

AbstractMassive star clusters in the Magellanic Clouds are observed to follow a striking trend in size with age – older clusters exhibit a much greater spread in core radius than do younger clusters, which are generally compact. We present results from realistic N-body modelling of massive star clusters, aimed at investigating a dynamical origin for the radius-age trend. We find that stellar-mass black holes, formed as remnants of the most massive stars in a cluster, can constitute a dynamically important population. If retained, these objects rapidly form a dense core where interactions are common, resulting in the scattering of black holes into the cluster halo, and the ejection of black holes from the cluster. These processes heat the stellar component, resulting in prolonged core expansion of a magnitude matching the observations. Core expansion at early times does not result from the action of black holes, but can be reproduced by the effects of rapid mass-loss due to stellar evolution in a primordially mass segregated cluster.

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Resolved Massive Star Clusters in the Milky Way and Its Satellites: Brightness Profiles and a Catalog of Fundamental Parameters

The Astrophysical Journal Supplement Series ◽

10.1086/497429 ◽

2005 ◽

Vol 161 (2) ◽

pp. 304-360 ◽

Cited By ~ 501

Author(s):

Dean E. McLaughlin ◽

Roeland P. van der Marel

Keyword(s):

Massive Star ◽

Milky Way ◽

Star Clusters ◽

Fundamental Parameters

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Contribution of globular clusters to halos

Proceedings of the International Astronomical Union ◽

10.1017/s1743921315009138 ◽

2015 ◽

Vol 12 (S316) ◽

pp. 287-293

Author(s):

Angela Bragaglia

Keyword(s):

Star Formation ◽

Formation Mechanism ◽

Globular Clusters ◽

Massive Star ◽

Milky Way ◽

Star Clusters ◽

Early Evolution ◽

Light Elements ◽

Halo Stars ◽

Chemical Signatures

AbstractThe contribution of massive star clusters to their hosting halo dramatically depends on their formation mechanism and their early evolution. Massive globular clusters in the Milky Way (and in other galaxies) have been shown to display peculiar chemical patterns (light-elements correlations and anti-correlations) indicative of a complex star formation, confirmed by photometric evidence (spread or split sequences). I use these chemical signatures to try to understand what is the fraction of halo stars originally born in globular clusters.

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The connection between stellar and nuclear clusters: Can an IMBH be sitting at the heart of the Milky Way?

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319007324 ◽

2019 ◽

Vol 14 (S351) ◽

pp. 51-55

Author(s):

Manuel Arca Sedda

Keyword(s):

Massive Star ◽

Milky Way ◽

Star Clusters ◽

Galactic Nuclei ◽

Intermediate Mass ◽

Tidal Disruption ◽

Vast Number ◽

Supermassive Black Hole ◽

Nuclear Clusters ◽

Nuclear Cluster

AbstractA vast number of observed galactic nuclei are known to harbour a central supermassive black hole (SMBH). In their early lifetime, these systems might have witnessed the strong interaction between the SMBH and massive star clusters formed in the inner galactic regions. Due to the strong tidal field exerted from the SMBH, clusters are likely to undergo tidal disruption, releasing their stars all around the SMBH, and possibly driving the formation of a nuclear cluster (NC). This mechanism can contribute to populate galactic nuclei with intermediate-mass black holes (IMBH). Interactions with the central SMBH can lead to the formation of tight massive BH binaries (MBBH) that undergo coalescence via gravitational waves (GW) emission. We discuss this mechanism in the context of the Milky Way centre, exploring the possibility that SgrA*, the Galactic SMBH, has an IMBH companion.

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Ages of Galactic and Extragalactic Star Clusters of Various Abundances

Highlights of Astronomy ◽

10.1017/s1539299600005025 ◽

1983 ◽

Vol 6 ◽

pp. 109-117 ◽

Cited By ~ 3

Author(s):

R.D. Cannon

Keyword(s):

Star Clusters ◽

Magellanic Clouds ◽

Open Clusters ◽

Simultaneous Solution ◽

Low Mass Stars ◽

Cluster Systems ◽

Distant Cluster ◽

Low Mass

In this review I shall concentrate mainly on globular star clusters in our Galaxy since these are the objects for which most work has been done recently, both observationally and theoretically. However, I shall also discuss briefly the oldest open clusters and clusters in the Magellanic Clouds. Little can be said about more distant cluster systems, since the only observations available are of integrated colours or spectra and these seem to be rather unreliable indicators of age. It is perhaps worth pointing out that the title may be slightly misleading; the problem is not so much to determine the ages of clusters of known abundances, as to obtain the best simultaneous solution for both age and composition, since some of the most important abundances (notably helium and oxygen) are virtually unobservable in little-evolved low mass stars.

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The accreted nuclear clusters of the Milky Way

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3407 ◽

2020 ◽

Vol 500 (2) ◽

pp. 2514-2524

Author(s):

Joel Pfeffer ◽

Carmela Lardo ◽

Nate Bastian ◽

Sara Saracino ◽

Sebastian Kamann

Keyword(s):

Globular Clusters ◽

Milky Way ◽

Dwarf Galaxy ◽

Star Clusters ◽

Host Galaxy ◽

The Galaxy ◽

Nuclear Clusters ◽

The Common ◽

Massive Clusters ◽

Peculiar Case

ABSTRACT A number of the massive clusters in the halo, bulge, and disc of the Galaxy are not genuine globular clusters (GCs) but instead are different beasts altogether. They are the remnant nuclear star clusters (NSCs) of ancient galaxies since accreted by the Milky Way. While some clusters are readily identifiable as NSCs and can be readily traced back to their host galaxy (e.g. M54 and the Sagittarius Dwarf galaxy), others have proven more elusive. Here, we combine a number of independent constraints, focusing on their internal abundances and overall kinematics, to find NSCs accreted by the Galaxy and trace them to their accretion event. We find that the true NSCs accreted by the Galaxy are: M54 from the Sagittarius Dwarf, ω Centari from Gaia-Enceladus/Sausage, NGC 6273 from Kraken, and (potentially) NGC 6934 from the Helmi Streams. These NSCs are prime candidates for searches of intermediate-mass black holes (BHs) within star clusters, given the common occurrence of galaxies hosting both NSCs and central massive BHs. No NSC appears to be associated with Sequoia or other minor accretion events. Other claimed NSCs are shown not to be such. We also discuss the peculiar case of Terzan 5, which may represent a unique case of a cluster–cluster merger.

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From young massive star clusters to old globulars: long-term survival chances

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307001962 ◽

2006 ◽

Vol 2 (S237) ◽

pp. 408-408

Author(s):

Richard de Grijs

Keyword(s):

Galaxy Formation ◽

Massive Star ◽

Cluster Formation ◽

Star Clusters ◽

Term Survival ◽

Star Forming ◽

Distant Galaxies ◽

Wide Range ◽

Galaxy Collisions

Young, massive star clusters (YMCs) are the most notable and significant end products of violent star-forming episodes triggered by galaxy collisions and close encounters. The question remains, however, whether or not at least a fraction of the compact YMCs seen in abundance in extragalactic starbursts, are potentially the progenitors of (≳10 Gyr) old globular cluster (GC)-type objects. If we could settle this issue convincingly, one way or the other, the implications of such a result would have far-reaching implications for a wide range of astrophysical questions, including our understanding of the process of galaxy formation and assembly, and the process and conditions required for star (cluster) formation. Because of the lack of a statistically significant sample of YMCs in the Local Group, however, we need to resort to either statistical arguments or to the painstaking approach of case-by-case studies of individual objects in more distant galaxies.

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