scholarly journals Star-cluster formation and evolution

2006 ◽  
Vol 2 (S237) ◽  
pp. 230-237 ◽  
Author(s):  
Pavel Kroupa
Keyword(s):  
Galaxy Formation ◽  
Cluster Formation ◽  
Star Clusters ◽  
Mass Function ◽  
Cluster Mass ◽  
Cluster Evolution ◽  
Stellar Component ◽  
Galaxy Formation And Evolution ◽  
Dynamical Time ◽  
Formation And Evolution

AbstractStar clusters are observed to form in a highly compact state and with low star-formation efficiencies, and only 10 per cent of all clusters appear to survive to middle- and old-dynamical age. If the residual gas is expelled on a dynamical time the clusters disrupt. Massive clusters may then feed a hot kinematical stellar component into their host-galaxy's field population thereby thickening galactic disks, a process that theories of galaxy formation and evolution need to accommodate. If the gas-evacuation time-scale depends on cluster mass, then a power-law embedded-cluster mass function may transform within a few dozen Myr to a mass function with a turnover near 105M, thereby possibly explaining this universal empirical feature. Discordant empirical evidence on the mass function of star clusters leads to the insight that the physical processes shaping early cluster evolution remain an issue of cutting-edge research.

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 Modeling Formation of Globular Clusters: Beacons of Galactic Star Formation

2010 ◽  
Vol 6 (S270) ◽  
pp. 381-384
Author(s):  
Oleg Y. Gnedin
Keyword(s):  
Star Formation ◽  
Galaxy Formation ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Cluster Formation ◽  
Star Clusters ◽  
Mass Function ◽  
Giant Molecular Clouds ◽  
Early Galaxies ◽  
The Masses

AbstractModern hydrodynamic simulations of galaxy formation are able to predict accurately the rates and locations of the assembly of giant molecular clouds in early galaxies. These clouds could host star clusters with the masses and sizes of real globular clusters. I describe current state-of-the-art simulations aimed at understanding the origin of the cluster mass function and metallicity distribution. Metallicity bimodality of globular cluster systems appears to be a natural outcome of hierarchical formation and gradually declining fraction of cold gas in galaxies. Globular cluster formation was most prominent at redshifts z > 3, when massive star clusters may have contributed as much as 20% of all galactic star formation.

scholarly journals The nature and nurture of star clusters

2009 ◽  
Vol 5 (S266) ◽  
pp. 3-13 ◽  
Author(s):  
Bruce G. Elmegreen
Keyword(s):  
Globular Clusters ◽  
Dwarf Galaxy ◽  
Cluster Formation ◽  
Star Clusters ◽  
Mass Function ◽  
Radial Gradient ◽  
Cluster Mass ◽  
Low Mass ◽  
Nature And Nurture ◽  
Gas Loss

AbstractStar clusters have hierarchical patterns in space and time, suggesting formation processes in the densest regions of a turbulent interstellar medium. Clusters also have hierarchical substructure when they are young, which makes them all look like the inner mixed parts of a pervasive stellar hierarchy. Young field stars share this distribution, presumably because some of them came from dissolved clusters and others formed in a dispersed fashion in the same gas. The fraction of star formation that ends up in clusters is apparently not constant, but may increase with interstellar pressure. Hierarchical structure explains why stars form in clusters and why many of these clusters are self-bound. It also explains the cluster mass function. Halo globular clusters share many properties of disk clusters, including what appears to be an upper cluster cutoff mass. However, halo globulars are self-enriched and often connected with dwarf galaxy streams. The mass function of halo globulars could have initially been like the power-law mass function of disk clusters, but the halo globulars have lost their low-mass members. The reasons for this loss are not understood. It could have happened slowly over time as a result of cluster evaporation, or it could have happened early after cluster formation as a result of gas loss. The latter model explains best the observation that the globular cluster mass function has no radial gradient in galaxies.

scholarly journals 3 things they don’t tell you about star clusters

2019 ◽  
Vol 14 (S351) ◽  
pp. 40-46 ◽  
Author(s):  
Florent Renaud
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Cluster Formation ◽  
Star Clusters ◽  
Matter Content ◽  
Star Cluster ◽  
Stellar Systems ◽  
Holistic View ◽  
Cosmological Context ◽  
Formation And Evolution

AbstractDense stellar systems in general and star clusters in particular have recently regained the interest of the extragalactic and even cosmology communities, due to the role they could play as actors and probes of re-ionization, galactic archeology and the dark matter content of galaxies, among many others. In the era of the exploitation and the preparation of large stellar surveys (Gaia, APOGEE, 4MOST, WEAVE), of the detection of gravitational waves mostly originating from dense regions like the cores of clusters (Ligo, LISA), and in an always more holistic view of galaxy formation (HARMONI, Euclid, LSST†), a complete theory on the formation and evolution of clusters is needed to interpret the on-going and forthcoming data avalanche. In this context, the community carries an effort to model the aspects of star cluster formation and evolution in galactic and even cosmological context. However, it is not always easy to understand the caveats and the shortcuts taken in theories and simulations, and their implications on the conclusions drawn. I take the opportunity of this document to highlight three of these topics and discuss why some shortcuts taken by the community are or could be misleading.

Disk Galaxies in the Magneticum Pathfinder Simulations

2014 ◽  
Vol 10 (S309) ◽  
pp. 145-148 ◽  
Author(s):  
Rhea-Silvia Remus ◽  
Klaus Dolag ◽  
Lisa K. Bachmann ◽  
Alexander M. Beck ◽  
Andreas Burkert ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Mass Function ◽  
Disk Galaxies ◽  
Physical Processes ◽  
Galaxy Formation And Evolution ◽  
Mass Size ◽  
Formation And Evolution ◽  
Galaxy Populations ◽  
Size Relation ◽  
The Universe

AbstractWe presentMagneticum Pathfinder, a new set of hydrodynamical cosmological simulations covering a large range of cosmological scales. Among the important physical processes included in the simulations are the chemical and thermodynamical evolution of the diffuse gas as well as the evolution of stars and black holes and the corresponding feedback channels. In the high resolution boxes aimed at studies of galaxy formation and evolution, populations of both disk and spheroidal galaxies are self-consistently reproduced. These galaxy populations match the observed stellar mass function and show the same trends for disks and spheroids in the mass–size relation as observations from the SDSS. Additionally, we demonstrate that the simulated galaxies successfully reproduce the observed specific angular-momentum–mass relations for the two different morphological types of galaxies. In summary, theMagneticum Pathfindersimulations are a valuable tool for studying the assembly of cosmic and galactic structures in the universe.

scholarly journals A Review of the Theory of Galactic Winds Driven by Stellar Feedback

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 114 ◽  
Author(s):  
Dong Zhang
Keyword(s):  
Galaxy Formation ◽  
Mass Function ◽  
Future Research ◽  
Star Forming ◽  
Stellar Feedback ◽  
Galactic Winds ◽  
Galaxy Formation And Evolution ◽  
Supernova Explosions ◽  
Formation And Evolution ◽  
Magnetohydrodynamic Simulations

Galactic winds from star-forming galaxies are crucial to the process of galaxy formation and evolution, regulating star formation, shaping the stellar mass function and the mass-metallicity relation, and enriching the intergalactic medium with metals. Galactic winds associated with stellar feedback may be driven by overlapping supernova explosions, radiation pressure of starlight on dust grains, and cosmic rays. Galactic winds are multiphase, the growing observations of emission and absorption of cold molecular, cool atomic, ionized warm and hot outflowing gas in a large number of galaxies have not been completely understood. In this review article, I summarize the possible mechanisms associated with stars to launch galactic winds, and review the multidimensional hydrodynamic, radiation hydrodynamic and magnetohydrodynamic simulations of winds based on various algorithms. I also briefly discuss the theoretical challenges and possible future research directions.

scholarly journals Star Clusters Near and Far

2020 ◽  
Vol 216 (4) ◽  
Author(s):  
Angela Adamo ◽  
Peter Zeidler ◽  
J. M. Diederik Kruijssen ◽  
Mélanie Chevance ◽  
Mark Gieles ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Globular Clusters ◽  
High Redshift ◽  
Cluster Formation ◽  
Star Clusters ◽  
Local Universe ◽  
Stellar Feedback ◽  
Formation And Evolution ◽  
Numerical And Analytical Methods ◽  
Fundamental Units

Abstract Star clusters are fundamental units of stellar feedback and unique tracers of their host galactic properties. In this review, we will first focus on their constituents, i.e. detailed insight into their stellar populations and their surrounding ionised, warm, neutral, and molecular gas. We, then, move beyond the Local Group to review star cluster populations at various evolutionary stages, and in diverse galactic environmental conditions accessible in the local Universe. At high redshift, where conditions for cluster formation and evolution are more extreme, we are only able to observe the integrated light of a handful of objects that we believe will become globular clusters. We therefore discuss how numerical and analytical methods, informed by the observed properties of cluster populations in the local Universe, are used to develop sophisticated simulations potentially capable of disentangling the genetic map of galaxy formation and assembly that is carried by globular cluster populations.

scholarly journals Young Star Clusters: Clues to Galaxy Formation and Evolution

2004 ◽  
Vol 217 ◽  
pp. 210-211
Author(s):  
Peter Anders ◽  
Uta Fritze-V. Alvensleben ◽  
Richard de Grijs
Keyword(s):  
Galaxy Formation ◽  
Globular Clusters ◽  
Star Clusters ◽  
Young Star ◽  
Star Formation History ◽  
Galaxy Formation And Evolution ◽  
First Results ◽  
History Of ◽  
Formation And Evolution ◽  
Young Clusters

Young clusters are observed to form in a variety of interacting galaxies and violent starbursts, a substantial number resembling the progenitors of the well-studied globular clusters in mass and size. By studying young clusters in merger remnants and peculiar galaxies, we can therefore learn about the violent star formation history of these galaxies. 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 that allows to determine individual cluster metallicities, ages, extinction values and masses from a comparison of a large grid of model Spectral Energy Distributions (SEDs) with multi-color observations. First results for the newly-born clusters in NGC 1569 are presented.

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