scholarly journals Open, Massive and Globular Clusters — Part of the Same Family?

2002 ◽  
Vol 207 ◽  
pp. 421-427 ◽  
Author(s):  
Søren S. Larsen
Keyword(s):  
Globular Clusters ◽  
Cluster Formation ◽  
Formation Rate ◽  
Star Clusters ◽  
Young Star ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Cluster Systems ◽  
Physical Description ◽  
Super Star Clusters

Populations of young star clusters show significant differences even among “normal” disk galaxies. In this contribution I discuss how properties of young cluster systems are related to those of their host galaxies, based on a recent study of clusters in a sample of 22 nearby spiral galaxies. Luminous young clusters similar to the “super” star clusters observed in starbursts and mergers exist in several of these galaxies, and it is found that the luminosity of the brightest star cluster as well as the specific luminosity of the cluster systems both correlate well with the host galaxy star formation rate. When considering star clusters in different environments the traditional distinction between “open”, “massive” and “globular” clusters breaks down, underscoring the need for a universal physical description of cluster formation.

scholarly journals The Formation and Evolution of Star Clusters and Galaxies

2005 ◽  
Vol 13 ◽  
pp. 347-349
Author(s):  
Stephen E. Zepf
Keyword(s):  
Galaxy Formation ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Near Infrared ◽  
Cluster Formation ◽  
Star Clusters ◽  
Elliptical Galaxies ◽  
Cluster Systems ◽  
Important Observation ◽  
Formation And Evolution

AbstractThis paper addresses the questions of what we have learned about how and when dense star clusters form, and what studies of star clusters have revealed about galaxy formation and evolution. One important observation is that globular clusters are observed to form in galaxy mergers and starbursts in the local universe, which both provides constraints on models of globular cluster formation, and suggests that similar physical conditions existed when most early-type galaxies and their globular clusters formed in the past. A second important observation is that globular cluster systems typically have bimodal color distributions. This was predicted by merger models, and indicates an episodic formation history for elliptical galaxies. A third and very recent result is the discovery of large populations of intermediate age globular clusters in several elliptical galaxies through the use of optical to near-infrared colors. These provide an important link between young cluster systems observed in starbursts and mergers and old cluster systems. This continuum of ages of the metal-rich globular cluster systems also indicates that there is no special age or epoch for the formation of the metal-rich globular clusters, which comprise about half of the cluster population. The paper concludes with a brief discussion of recent results on the globular cluster – low-mass X-ray binary connection.

scholarly journals The SUNBIRD survey: characterizing the super star cluster populations of intensely star-forming galaxies

2015 ◽  
Vol 12 (S316) ◽  
pp. 70-76
Author(s):  
Zara Randriamanakoto ◽  
Petri Väisänen
Keyword(s):  
Star Formation ◽  
Adaptive Optics ◽  
Near Infrared ◽  
Cluster Formation ◽  
Formation Rate ◽  
Star Clusters ◽  
Power Laws ◽  
Star Cluster ◽  
Host Galaxies ◽  
Star Forming

AbstractSuper star clusters (SSCs) represent the youngest and most massive form of known gravitationally bound star clusters in the Universe. They are born abundantly in environments that trigger strong and violent star formation. We investigate the properties of these massive SSCs in a sample of 42 nearby starbursts and luminous infrared galaxies. The targets form the sample of the SUperNovae and starBursts in the InfraReD (SUNBIRD) survey that were imaged using near-infrared (NIR) K-band adaptive optics mounted on the Gemini/NIRI and the VLT/NaCo instruments. Results from i) the fitted power-laws to the SSC K-band luminosity functions, ii) the NIR brightest star cluster magnitude − star formation rate (SFR) relation and iii) the star cluster age and mass distributions have shown the importance of studying SSC host galaxies with high SFR levels to determine the role of the galactic environments in the star cluster formation, evolution and disruption mechanisms.

scholarly journals Probing Globular Cluster Formation in Low Metallicity Dwarf Galaxies

2008 ◽  
Vol 4 (S255) ◽  
pp. 366-369
Author(s):  
Kelsey E. Johnson ◽  
Leslie K. Hunt ◽  
Amy E. Reines
Keyword(s):  
Globular Clusters ◽  
Massive Star ◽  
Dwarf Galaxies ◽  
Cluster Formation ◽  
Formation Rate ◽  
Star Clusters ◽  
Initial Study ◽  
Spectral Energy ◽  
Massive Galaxies ◽  
Low Metallicity

AbstractThe ubiquitous presence of globular clusters around massive galaxies today suggests that these extreme star clusters must have been formed prolifically in the earlier universe in low-metallicity galaxies. Numerous adolescent and massive star clusters are already known to be present in a variety of galaxies in the local universe; however most of these systems have metallicities of 12 + log(O/H) > 8, and are thus not representative of the galaxies in which today's ancient globular clusters were formed. In order to better understand the formation and evolution of these massive clusters in environments with few heavy elements, we have targeted several low-metallicity dwarf galaxies with radio observations, searching for newly-formed massive star clusters still embedded in their birth material. The galaxies in this initial study are HS 0822+3542, UGC 4483, Pox 186, and SBS 0335-052, all of which have metallicities of 12 + log(O/H) < 7.75. While no thermal radio sources, indicative of natal massive star clusters, are found in three of the four galaxies, SBS 0335-052 hosts two such objects, which are incredibly luminous. The radio spectral energy distributions of these intense star-forming regions in SBS 0335-052 suggest the presence of ~12,000 equivalent O-type stars, and the implied star formation rate is nearing the maximum starburst intensity limit.

scholarly journals Young Star Clusters: Metallicity Tracers in External Galaxies

2005 ◽  
Vol 13 ◽  
pp. 667-669
Author(s):  
Peter Anders ◽  
Uta Fritze – v. Alvensleben ◽  
Richard de Grijs
Keyword(s):  
Star Formation ◽  
Cluster Formation ◽  
Star Clusters ◽  
Young Star ◽  
Interacting Galaxies ◽  
Star Formation History ◽  
Host Galaxy ◽  
Chemical Enrichment ◽  
Major Mode ◽  
First Results

AbstractStar cluster formation is a major mode of star formation in the extreme conditions of interacting galaxies and violent star bursts. These newly-formed clusters are built from recycled gas, pre-enriched to various levels within the interacting galaxies. Hence, star clusters of different ages represent a fossil record of the chemical enrichment history of their host galaxy, as well as of the host galaxy’s violent star formation history. We present a new set of evolutionary synthesis models of our GALEV code, specifically developed to include the gaseous emission of presently forming star clusters, and a new tool to analyze multi-color observations with our models. First results for newly-born clusters in the dwarf star-burst galaxy NGC 1569 are presented.

Prodigious and Continuous Formation of Super Star Clusters from Cooled Intracluster Gas

2018 ◽  
Vol 14 (S342) ◽  
pp. 108-111
Author(s):  
Jeremy Lim ◽  
Emily Wong ◽  
Youichi Ohyama ◽  
Tom Broadhurst ◽  
Elinor Medezinski
Keyword(s):  
Globular Clusters ◽  
Elliptical Galaxy ◽  
Star Clusters ◽  
Elliptical Galaxies ◽  
Young Star ◽  
Continuous Formation ◽  
Steady Rate ◽  
Super Star Clusters ◽  
Ngc 1275 ◽  
Intracluster Gas

AbstractGlobular clusters (GCs) — compact and massive star clusters found ubiquitously around galaxies — are believed to be ancient relics (ages ≳ 10 Gyr) from the early formative phase of galaxies, although their physical origin remains widely debated. The most numerous GC populations are hosted by giant elliptical galaxies, where they can exhibit a broad dispersion in colour interpreted as a wide spread in metallicity. Here, we show that many thousands of similarly compact and massive super star clusters have formed at an approximately steady rate over, at least, the past ~1 Gyr around the nearby giant elliptical galaxy, NGC 1275, at the centre of the Perseus cluster. The number distribution of these young star clusters appears to exhibit a similar dependence in luminosity and mass as the even more numerous but older GCs around NGC 1275. In just a few Gyr, these super star clusters will evolve to become indistinguishable in broadband optical colours from the older GCs, and their spread in age add to the dispersion in colour of these GCs. The spatial distribution of the super star clusters resembles the filamentary network of multiphase gas in the cluster core, implying that they formed from molecular gas amassed from cooling of the hot intracluster gas. The sustained formation of super star clusters from cooled intracluster gas constitutes a previously unrecognised but prodigious source of GCs over cosmic timescales, and contributes to both their enormous numbers and broad colour dispersion in giant elliptical galaxies.

scholarly journals Formation and Disruption of Globular Star Clusters

2002 ◽  
Vol 207 ◽  
pp. 566-576 ◽  
Author(s):  
S. Michael Fall ◽  
Qing Zhang
Keyword(s):  
Globular Clusters ◽  
Star Clusters ◽  
Mass Function ◽  
Star Cluster ◽  
Weak Dependence ◽  
Host Galaxies ◽  
Physical Processes ◽  
Cluster Systems ◽  
Luminosity Functions ◽  
Characteristic Mass

In the first part of this article, we review observations of the mass and luminosity functions of young and old star cluster systems. We also review some of the physical processes that may determine the characteristic mass of globular clusters and the form of their mass function. In the second part of this article, we summarize our models for the disruption of clusters and the corresponding evolution of the mass function. Much of our focus here is on understanding why the mass function of globular clusters has no more than a weak dependence on radius within their host galaxies.

scholarly journals The Imprints Of Galactic Environment On Cluster Formation and Evolution

2015 ◽  
Vol 12 (S316) ◽  
pp. 17-24
Author(s):  
Angela Adamo
Keyword(s):  
Star Formation ◽  
Formation Process ◽  
Globular Clusters ◽  
High Redshift ◽  
Cluster Formation ◽  
Large Population ◽  
Star Clusters ◽  
Young Star ◽  
Star Formation History ◽  
Formation History

AbstractYoung star clusters (YSCs) appear to be a ubiquitous product of star formation in local galaxies, thus, they can be used to study the star formation process at work in their host galaxies. Moreover, YSCs are intrinsically brighter that single stars, potentially becoming the most important tracers of the recent star formation history in galaxies in the local Universe. In local galaxies, we also witness the presence of a large population of evolved star clusters, commonly called globular clusters (GCs). GCs peak formation history is very close to the redshift (z ~ 2) when the cosmic star formation history reached the maximum. Therefore, GCs are usually associated to extreme star formation episodes in high-redshift galaxies. It is yet not clear whether YSCs and GCs share a similar formation process (same physics under different interstellar medium conditions) and evolution process, and whether the former can be used as progenitor analogs of the latter. In this invited contribution, I review general properties of YSC populations in local galaxies. I will summarise some of the current open questions in the field, with particular emphasis to whether or not galactic environments, where YSCs form, leave imprints on the nested populations. The importance of this rapidly developing field can be crucial in understanding GC formation and possibly the galactic environment condition where this ancient population formed.

scholarly journals The Formation of Globular Cluster Systems: how, when, and where?

1996 ◽  
Vol 171 ◽  
pp. 87-95
Author(s):  
William E. Harris
Keyword(s):  
Galaxy Formation ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Cluster Formation ◽  
Star Clusters ◽  
Cluster Systems ◽  
The Right

Globular clusters, as fossil remnants of the protogalactic era, provide unique traces of the earliest events of galaxy formation. However, new observations – especially from HST – are showing that massive, globular-like star clusters belong not only to the pregalactic era but can form right up to the present day under the right circumstances. Appropriate interpretation may now let us learnsimultaneouslyabout the process of cluster formation as well as the nature of the gaseous fragments from which the galaxies were assembled.

scholarly journals “Super” Star Clusters

2005 ◽  
Vol 13 ◽  
pp. 363-365
Author(s):  
Richard de Grijs
Keyword(s):  
Globular Clusters ◽  
Milky Way ◽  
Compact Star ◽  
Cluster Formation ◽  
Survival Rates ◽  
Extreme Environments ◽  
Star Clusters ◽  
Building Blocks ◽  
Initial Mass Function ◽  
Super Star Clusters

AbstractThe production of “super star clusters” (SSCs; luminous, compact star clusters) seems to be a hallmark of intense star formation, particularly in interacting and star-burst galaxies. Their sizes, luminosities, and mass estimates are entirely consistent with what is expected for young Milky Way-type globular clusters (GCs). SSCs are important because of what they can tell us about GC formation and evolution (e.g., initial characteristics and early survival rates). They are also of prime importance as probes of the formation and (chemical) evolution of their host galaxies, and of the initial mass function in the extreme environments required for cluster formation. Recent evidence lends support to the scenario that Milky Way-type GCs (although more metal rich), which were once thought to be the oldest building blocks of galaxies, are still forming today.

scholarly journals Star and Globular Cluster Formation in Mergers

1996 ◽  
Vol 171 ◽  
pp. 376-376
Author(s):  
Uta Fritze - v. Alvensleben
Keyword(s):  
Star Formation ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Cluster Formation ◽  
Star Clusters ◽  
Young Star ◽  
Evolutionary Synthesis ◽  
Secondary Population ◽  
Ngc 1275 ◽  
Young Star Clusters

The high burst strengths and star formation efficiencies found with spectrophotmetric and chemical evolutionary synthesis for mergers of gas-rich spirals led us to expect the formation of a secondary population of globular clusters (GC) with enhanced metallicity (F. – v. A. & Gerhard 1994, A&A 285, 751 u.775). HST imaging of NGC 7252, NGC 4038/39 and NGC 1275 revealed rich populations of bright young star clusters (YSC).

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