scholarly journals Massive star cluster formation and evolution in tidal dwarf galaxies

2019 ◽  
Vol 628 ◽  
pp. A60 ◽  
Author(s):  
Jérémy Fensch ◽  
Pierre-Alain Duc ◽  
Médéric Boquien ◽  
Debra M. Elmegreen ◽  
Bruce G. Elmegreen ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Massive Star ◽  
Dwarf Galaxies ◽  
Cluster Formation ◽  
Spectral Energy Distribution ◽  
Star Clusters ◽  
Star Cluster ◽  
Spectral Energy ◽  
Physical Parameters ◽  
Near Ultraviolet

Context. The formation of globular clusters remains an open debate. Dwarf starburst galaxies are efficient at forming young massive clusters with similar masses as globular clusters and may hold the key to understanding their formation. Aims. We study star cluster formation in a tidal debris, including the vicinity of three tidal dwarf galaxies, in a massive gas-dominated collisional ring around NGC 5291. These dwarfs have physical parameters that differ significantly from local starbursting dwarfs. They are gas rich, highly turbulent, their gas metallicity is already enriched up to half solar values, and they are expected to be free of dark matter. The aim is to study massive star cluster formation in this as yet unexplored type of environment. Methods. We used imaging from the Hubble Space Telescope using broadband filters that cover the wavelength range from the near-ultraviolet to the near-infrared. We determined the masses and ages of the cluster candidates by using the spectral energy distribution-fitting code CIGALE. We considered age-extinction degeneracy effects on the estimation of the physical parameters. Results. We find that the tidal dwarf galaxies in the ring of NGC 5291 are forming star clusters with an average efficiency of ∼40%, which is similar to blue compact dwarf galaxies. We also find massive star clusters for which the photometry suggests that they were formed at the very birth of the tidal dwarf galaxies. These clusters have survived for several hundred million years. Therefore our study shows that extended tidal dwarf galaxies and compact clusters may be formed simultaneously. In the specific case observed here, the young star clusters are not massive enough to survive for a Hubble time. However, it may be speculated that similar objects at higher redshift, with a higher star formation rate, might form some of the long-lived globular clusters.

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 Ages and Masses of Star Clusters in M33: a Multiwavelength Study

2021 ◽  
Vol 163 (1) ◽  
pp. 16
Author(s):  
Caitlin Moeller ◽  
Daniela Calzetti
Keyword(s):  
Spectral Energy Distribution ◽  
Star Clusters ◽  
Young Star ◽  
Star Cluster ◽  
Spectral Energy ◽  
Physical Parameters ◽  
Nearby Galaxy ◽  
Population Synthesis ◽  
Cluster Evolution ◽  
The Masses

Abstract We combine archival images for the nearby galaxy M33 (Triangulum Galaxy) from the ultraviolet (UV) to the infrared to derive ages, masses, and extinctions for the young star cluster population, and compare our physical parameters with published ones. Our goal is to test the robustness of clusters ages and masses, and possibly improve on existing ones both by expanding the wavelength range of the spectral-energy distribution (SED) fits and by using more recent population synthesis models. The rationale for this experiment is to verify the sensitivity of the clusters physical parameters to observational setups and model choices that span those commonly found in the literature. We derive the physical parameters of 137 clusters, using SEDs measured in eight UV-to-I bands, including Hα, from GALEX and ground-based images. We also add the 24 μm image from the Spitzer Space Telescope to help break some age degeneracies. We find that our derived cluster ages show significant differences with earlier determinations, while the masses remain relatively insensitive to the fitting approach adopted. We also highlight an already known difficulty in recovering old, low-extinction clusters, as SED-fitting codes tend to prefer younger, higher extinction solutions when the extinction is a free parameter. We publish updated ages, masses, and extinctions, with uncertainties for all sample star clusters, together with their photometry. Given the proximity of M33, this represents an important population to secure for the study of star formation and cluster evolution in spirals.

scholarly journals Theoretical evolutionary framework for low-mass stars in massive star clusters

2015 ◽  
Vol 12 (S316) ◽  
pp. 320-327
Author(s):  
Santi Cassisi
Keyword(s):  
Energy Distribution ◽  
Globular Clusters ◽  
Massive Star ◽  
Spectral Energy Distribution ◽  
Star Clusters ◽  
Spectral Energy ◽  
Stellar Systems ◽  
Low Mass Stars ◽  
Specific Chemical ◽  
Low Mass

AbstractRecent spectroscopic and photometric surveys of Galactic Globular Clusters have shown that these stellar systems host distinct sub-populations of stars characterised by peculiar chemical patterns. In the following we wish to address the issue of how these specific chemical patterns affect both the structural and evolutionary properties of stars as well as their spectral energy distribution. The implications of these effects on the photometric appearance of multiple stellar populations in different photometric planes are also briefly discussed.

scholarly journals On the Origin of Complex Stellar Populations in Star Clusters

2007 ◽  
Vol 3 (S246) ◽  
pp. 71-72
Author(s):  
J. Pflamm-Altenburg ◽  
P. Kroupa
Keyword(s):  
Star Formation ◽  
Globular Clusters ◽  
Massive Star ◽  
Cluster Formation ◽  
Star Clusters ◽  
Stellar Populations ◽  
Star Cluster ◽  
Young Stars

AbstractThe existence of complex stellar populations in some star clusters challenges the understanding of star formation. E.g. the ONC or the sigma Orionis cluster host much older stars than the main bulk of the young stars. Massive star clusters (ω Cen, G1, M54) show metallicity spreads corresponding to different stellar populations with large age gaps. We show that (i) during star cluster formation field stars can be captured and (ii) very massive globular clusters can accrete gas from a long-term embedding inter stellar medium and restart star formation.

scholarly journals Massive star clusters in galaxies

2010 ◽  
Vol 368 (1913) ◽  
pp. 889-906 ◽  
Author(s):  
William E. Harris
Keyword(s):  
Recent Work ◽  
Globular Clusters ◽  
Evolutionary History ◽  
Massive Star ◽  
Star Clusters ◽  
Star Cluster ◽  
Cluster System ◽  
History Of ◽  
Review Current

The ensemble of all star clusters in a galaxy constitutes its star cluster system . In this review, the focus of the discussion is on the ability of star clusters, particularly the systems of old massive globular clusters (GCs), to mark the early evolutionary history of galaxies. I review current themes and key findings in GC research, and highlight some of the outstanding questions that are emerging from recent work.

scholarly journals Spectroscopic study of formation, evolution and interaction of M31 and M33 with star clusters

2014 ◽  
Vol 10 (S312) ◽  
pp. 201-202 ◽  
Author(s):  
Zhou Fan ◽  
Yanbin Yang
Keyword(s):  
Globular Clusters ◽  
Stellar Population ◽  
Local Group ◽  
Spiral Galaxies ◽  
Star Clusters ◽  
Star Cluster ◽  
Physical Parameters ◽  
Cluster Systems ◽  
Nearby Galaxies ◽  
Formation And Evolution

AbstractThe recent studies show that the formation and evolution process of the nearby galaxies are still unclear. By using the Canada France Hawaii Telescope (CFHT) 3.6m telescope, the PanDAS shows complicated substructures (dwarf satellite galaxies, halo globular clusters, extended clusters, star streams, etc.) in the halo of M31 to ~150 kpc from the center of galaxy and M31-M33 interaction has been studied. In our work, we would like to investigate formation, evolution and interaction of M31 and M33, which are the nearest two spiral galaxies in Local Group. The star cluster systems of the two galaxies are good tracers to study the dynamics of the substructures and the interaction. Since 2010, the Xinglong 2.16m, Lijiang 2.4m and MMT 6.5m telescopes have been used for our spectroscopic observations. The radial velocities and Lick absorption-line indices can thus be measured with the spectroscopy and then ages, metallicities and masses of the star clusters can be fitted with the simple stellar population models. These parameters could be used as the input physical parameters for numerical simulations of M31-M33 interaction.

Young, old, massive: Steps to understanding globular cluster formation

2019 ◽  
Vol 14 (S351) ◽  
pp. 3-12
Author(s):  
William E. Harris
Keyword(s):  
Galaxy Evolution ◽  
Globular Clusters ◽  
Massive Star ◽  
Cluster Formation ◽  
Star Clusters ◽  
Dynamical Evolution ◽  
Mass Range ◽  
High Mass ◽  
Theoretical Modelling ◽  
Giant Molecular Clouds

AbstractOn observational grounds we now know a huge amount about the characteristics of massive star clusters in galaxies of all types, from the smallest dwarfs to the most massive giants and even into the Intracluster Medium. The old globular clusters (GCs) in particular exhibit a high degree of uniformity across all these environments in their physical properties including scale size, luminosity distribution, metallicity distribution, and age. As survivors of a long period of dynamical evolution, they are “unusual, but not special” among star clusters.The past few years have seen major advances in theoretical modelling that are starting to reveal how these massive star clusters formed in the early stages of galaxy evolution. Several suites of models point to their emergence in GMCs (Giant Molecular Clouds), which provide the turbulent big reservoirs of gas within which star clusters can be built. At cluster masses ∼105M⊙ and above, clusters form hierarchically through a nearly equal combination of direct gas accretion, and mergers with smaller clusters scattered throughout the GMC. GCs and YMCs (young massive clusters) in this high mass range should therefore be composite systems right from birth. To make such high-mass clusters, host GMCs of ∼107M⊙ are needed, and these are most commonly found in galaxies at redshifts z ≳ 2.

scholarly journals Compact Stellar Systems in the Fornax Cluster: Super-massive Star Clusters or Extremely Compact Dwarf Galaxies?

2000 ◽  
Vol 17 (3) ◽  
pp. 227-233 ◽  
Author(s):  
M. J. Drinkwater ◽  
J. B. Jones ◽  
M. D. Gregg ◽  
S. Phillipps
Keyword(s):  
Globular Clusters ◽  
Massive Star ◽  
Dwarf Galaxies ◽  
Stellar System ◽  
Star Clusters ◽  
Compact Objects ◽  
High Dispersion ◽  
Stellar Systems ◽  
Absolute Magnitudes ◽  
Fornax Cluster

AbstractWe describe a population of compact objects in the centre of the Fornax Cluster which were discovered as part of our 2dF Fornax Spectroscopic Survey. These objects have spectra typical of old stellar systems, but are unresolved on photographic sky survey plates. They have absolute magnitudes −13 < MB < −11, so they are 10 times more luminous than any Galactic globular clusters, but fainter than any known compact dwarf galaxies. These objects are all within 30 arcminutes of the central galaxy of the cluster, NGC 1399, but are distributed over larger radii than the globular cluster system of that galaxy. We suggest that these objects are either super-massive star clusters (intra-cluster globular clusters or tidally stripped nuclei of dwarf galaxies) or a new type of low-luminosity, compact elliptical dwarf (‘M32-type”) galaxy. The best way to test these hypotheses will be to obtain high-resolution imaging and high-dispersion spectroscopy to determine their structures and mass-to-light ratios. This will allow us to compare them to known compact objects and establish whether they represent a new class of hitherto unknown stellar system.

scholarly journals Multiple stellar populations in massive LMC star clusters

2008 ◽  
Vol 4 (S256) ◽  
pp. 305-310
Author(s):  
A. D. Mackey ◽  
P. Broby Nielsen ◽  
A. M. N. Ferguson ◽  
J. C. Richardson
Keyword(s):  
Globular Clusters ◽  
Main Sequence ◽  
Cluster Formation ◽  
Star Clusters ◽  
Stellar Populations ◽  
Star Cluster ◽  
Magellanic Clouds ◽  
Formation And Evolution ◽  
Galactic Globular Clusters

AbstractThe recent discovery of multiple stellar populations in massive Galactic globular clusters poses a serious challenge for models of star cluster formation and evolution. A new angle on this problem is being provided by rich intermediate-age clusters in the Magellanic Clouds. In this contribution we describe the discovery of three such LMC clusters with peculiar main-sequence turn-off morphologies. The simplest interpretation of our observations is that each of these three clusters is comprised of two or more stellar populations spanning an age interval of ~300 Myr. Surprisingly, such features may not be unusual in this type of cluster.

scholarly journals Simulations of Massive Star Cluster Formation and Feedback in Turbulent Giant Molecular Clouds

2010 ◽  
Vol 6 (S270) ◽  
pp. 235-238 ◽  
Author(s):  
Elizabeth Harper-Clark ◽  
Norman Murray
Keyword(s):  
Star Formation ◽  
Molecular Clouds ◽  
Massive Star ◽  
Cluster Formation ◽  
Star Clusters ◽  
Star Cluster ◽  
Giant Molecular Clouds

AbstractUsing the AMR code ENZO we are simulating the formation of massive star clusters within turbulent Giant Molecular Clouds (GMCs). Here we discuss the simulations from the first stages of building realistic turbulent GMCs, to accurate star formation, and ultimately comprehensive feedback. These simulations aim to build a better understanding of how stars affect GMCs, helping to answer the questions of how long GMCs live and why only a small fraction of the GMC gas becomes stars.

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