scholarly journals Multiple bursts of star formation in young star clusters: The case of the Orion Nebula Cluster

2019 ◽  
Vol 14 (S351) ◽  
pp. 200-203
Author(s):  
Tereza Jerabkova
Keyword(s):  
Star Formation ◽  
Cluster Formation ◽  
Star Clusters ◽  
Stellar Populations ◽  
Young Star ◽  
Orion Nebula ◽  
Stellar Feedback ◽  
Magnitude Diagram ◽  
Young Star Clusters ◽  
Gaia Dr2

AbstractYoung star clusters (YSCs) with resolved stellar populations are well suited for studying star-cluster formation. In most cases, the (pre-main-sequence) stellar populations found in the YSCs are coeval with an intrinsic age spread of up to 1Myr. Such observations can be understood as the YSCs having formed in one burst, which star formation was truncated by stellar feedback. The recent discovery that the colour-magnitude diagram of the Orion Nebula Clusters (ONC) contains three well defined age-separated populations appears to shatter this model. The implication is that the ONC formed in three bursts, with star formation still on-going in the last burst. We present new observational results focusing on the three populations in the ONC using OmegaCAM photometry and Gaia DR2 measurements. We also describe a theoretical model which may explain these observations by an interplay between stellar feedback and cluster dynamics.

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).

scholarly journals Star Clusters and Stellar Populations of the M31 Disk as Viewed by HST

2002 ◽  
Vol 207 ◽  
pp. 149-151
Author(s):  
Benjamin F. Williams ◽  
Paul W. Hodge
Keyword(s):  
Star Clusters ◽  
Stellar Populations ◽  
Young Star ◽  
Young Stars ◽  
New Method ◽  
Data Archive ◽  
Stellar Photometry ◽  
Identification Method ◽  
Ob Associations ◽  
Young Star Clusters

We present a new method for finding associations of young stars in M31 using broadband WFPC2 data from the HST data archive. Applying our identification method to 13 WFPC2 fields, covering an area of ∼60 arcmin2, has revealed 80 new candidate young star clusters in these portions of the M31 disk. Most of these clusters are small (≳5 pc) young (∼10–200 Myr) star groups located within large OB associations. We have estimated the reddening values and the ages of each candidate individually by fitting isochrones to the stellar photometry. We provide a catalogue of the candidates including rough approximations of their reddenings and ages.

scholarly journals Constraining star formation timescales with molecular gas and young star clusters

2019 ◽  
Vol 15 (S352) ◽  
pp. 350-352
Author(s):  
Kathryn Grasha ◽  
Daniela Calzetti
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Star Clusters ◽  
Young Star ◽  
Molecular Gas ◽  
Gas Reservoirs ◽  
Multi Wavelength ◽  
Predictive Theory ◽  
Young Star Clusters ◽  
Co Observations

AbstractStar formation provides insight into the physical processes that govern the transformation of gas into stars. A key missing piece in a predictive theory of star formation is the link between scales of individual stars and star clusters up to entire galaxies. LEGUS is now providing the information to test the overall organization and spatial evolution of star formation. We present our latest findings of using star clusters from LEGUS combined with ALMA CO observations to investigate the transition from molecular gas to star formation in local galaxies. This work paves the way for future JWST observations of the embedded phase of star formation, the last missing ingredient to connect young star clusters and their relation with gas reservoirs. Multi-wavelength studies of local galaxies and their stellar and gas components will help shed light on early phases of galaxy evolution and properties of the ISM at high-z.

scholarly journals Formation of Young Star Clusters

2005 ◽  
Vol 13 ◽  
pp. 358-362
Author(s):  
Bruce Elmegreen
Keyword(s):  
Star Formation ◽  
Energy Dissipation ◽  
Star Clusters ◽  
Young Star ◽  
Formation Processes ◽  
Stellar Objects ◽  
Scale Free ◽  
Self Gravity ◽  
Young Star Clusters ◽  
Mass Functions

AbstractTurbulence, self-gravity, and cooling convert most of the interstellar medium into cloudy structures that form stars. Turbulence compresses the gas into clouds directly and it moves pre-existing clouds around passively when there are multiple phases of temperature. Self-gravity also partitions the gas into clouds, forming giant regular complexes in spiral arms and in resonance rings and contributing to the scale-free motions generated by turbulence. Dense clusters form in the most strongly self-gravitating cores of these clouds, often triggered by compression from local stars. Pre-star formation processes inside clusters are not well observed, but the high formation rates and high densities of pre-stellar objects, and their power law mass functions suggest that turbulence, self-gravity, and energy dissipation are involved there too.

scholarly journals A Dynamical Origin for Early Mass Segregation in Young Star Clusters

2007 ◽  
Vol 3 (S246) ◽  
pp. 41-45
Author(s):  
Steve McMillan ◽  
Enrico Vesperini ◽  
Simon Portegies Zwart
Keyword(s):  
Cluster Formation ◽  
Star Clusters ◽  
Young Star ◽  
Mass Segregation ◽  
Young Star Clusters ◽  
Dynamical Origin ◽  
Significant Mass

AbstractSome young star clusters show a degree of mass segregation that is inconsistent with the effects of standard two-body relaxation from an initially unsegregated system without substructure, in virial equilibrium, and it is unclear whether current cluster formation models can account for this degree of initial segregation in clusters of significant mass. We show that mergers of small clumps that are either initially mass segregated, or in which mass segregation can be produced by two-body relaxation before they merge, generically lead to larger systems which inherit the progenitor clumps' segregation. We conclude that clusters formed in this way are naturally mass segregated, accounting for the anomalous observations and suggesting that this process of prompt mass segregation due to initial clumping should be taken into account in models of cluster formation and dynamics.

scholarly journals The anatomy of a star-forming galaxy II: FUV heating via dust

2020 ◽  
Vol 499 (2) ◽  
pp. 2028-2041
Author(s):  
S M Benincasa ◽  
J W Wadsley ◽  
H M P Couchman ◽  
A R Pettitt ◽  
B W Keller ◽  
...  
Keyword(s):  
Star Formation ◽  
Energy Budget ◽  
Star Clusters ◽  
Young Star ◽  
Star Forming ◽  
Neutral Gas ◽  
Feedback Model ◽  
Science Application ◽  
Far Ultraviolet ◽  
Young Star Clusters

ABSTRACT Far-ultraviolet (FUV) radiation greatly exceeds UV, supernovae (SNe), and winds in the energy budget of young star clusters but is poorly modelled in galaxy simulations. We present results of the first isolated galaxy disc simulations to include photoelectric heating of gas via dust grains from FUV radiation self-consistently, using a ray-tracing approach that calculates optical depths along the source–receiver sightline. This is the first science application of the TREVR radiative transfer algorithm. We find that FUV radiation alone cannot regulate star formation. However, FUV radiation produces warm neutral gas and is able to produce regulated galaxies with realistic scale heights. FUV is also a long-range feedback and is more important in the outer discs of galaxies. We also use the superbubble feedback model, which depends only on the SN energy per stellar mass, is more physically realistic than common, parameter-driven alternatives and thus better constrains SN feedback impacts. FUV and SNe together can regulate star formation without producing too much hot ionized medium and with less disruption to the interstellar medium compared to SNe alone.

scholarly journals The Initial Mass Function in Young Star Clusters

1986 ◽  
Vol 7 ◽  
pp. 489-499
Author(s):  
Hans Zinnecker
Keyword(s):  
Star Formation ◽  
Recent Work ◽  
Star Clusters ◽  
Mass Function ◽  
Young Star ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Stellar Content ◽  
Young Star Clusters ◽  
The Imf

AbstractThis review discusses both the earlier and the most recent work on the IMF in young star clusters. It is argued that the study of the stellar content of young star clusters offers the best chance of developing a theory of star formation and of the IMF.

scholarly journals Formation of nuclear rings of barred galaxies and star formation therein

2013 ◽  
Vol 9 (S303) ◽  
pp. 43-53 ◽  
Author(s):  
Woong-Tae Kim ◽  
Woo-Young Seo ◽  
Yonghwi Kim
Keyword(s):  
Star Formation ◽  
Formation Rate ◽  
Star Clusters ◽  
Young Star ◽  
Centrifugal Barrier ◽  
Barred Galaxies ◽  
Contact Points ◽  
Nuclear Ring ◽  
Substructure Formation ◽  
Young Star Clusters

AbstractBarred galaxies contain substructures such as a pair of dust lanes and nuclear rings, with the latter being sites of intense star formation. We study the substructure formation as well as star formation in nuclear rings using numerical simulations. We find that nuclear rings form not by the Lindblad resonances, as previously thought, but by the centrifugal barrier that inflowing gas along dust lanes cannot overcome. This predicts a smaller ring in a more strongly barred galaxy, consistent with observations. Star formation rate (SFR) in a nuclear ring is determined primarily by the mass inflow rate to the ring. In our models, the SFR typically shows a short strong burst associated with the rapid gas infall and stays very small for the rest of the evolution. When the SFR is low, ages of young star clusters exhibit an azimuthal gradient along the ring since star formation takes place mostly near the contact points between the dust lanes and the nuclear ring. When the SFR is large, on the other hand, star formation is widely distributed throughout the whole length of the ring, with no apparent age gradient of star clusters. Since observed ring star formation appears long-lived with episodic bursts, our results suggest that the bar region should be replenished continually with fresh gas from outside.

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