scholarly journals Watching the Birth of Super Star Clusters

2004 ◽  
Vol 221 ◽  
pp. 125-130
Author(s):  
Jean L. Turner ◽  
Sara C. Beck
Keyword(s):  
Star Formation ◽  
Dwarf Galaxy ◽  
Star Clusters ◽  
Star Cluster ◽  
Molecular Gas ◽  
Radio Observations ◽  
General Properties ◽  
Super Star Clusters ◽  
Formation Efficiency ◽  
Very High

Subarcsecond infrared and radio observations yield important information about the formation of super star clusters from their surrounding gas. We discuss the general properties of ionized and molecular gas near young, forming SSCs, as illustrated by the prototypical young, forming super star cluster nebula in the dwarf galaxy NGC 5253. This super star cluster appears to have a gravitationally bound nebula, and the lack of molecular gas suggests a very high star formation efficiency, consistent with the formation of a large, bound cluster.

scholarly journals Star Clusters in Giant Extragalactic HII Regions

2002 ◽  
Vol 207 ◽  
pp. 439-444
Author(s):  
Yu Zhi-yao
Keyword(s):  
Star Formation ◽  
Key Words ◽  
Star Clusters ◽  
Hii Regions ◽  
Star Cluster ◽  
Continuum Radiation ◽  
Hii Region ◽  
Lyman Continuum ◽  
Formation Efficiency ◽  
The Relationship

In this paper we study the relationship between the star formation efficiency and luminosity of Hα emission, Lyman continuum radiation, and Hβ emission on 35 giant extragalactic HII regions in seven galaxies. Using the observational results we obtain the relationship, and find that the star formation efficiency is correlation with Halpha luminocity, and Lyman continuum luminosity, and Hβ lumonosity, respectively. Key words: external galaxy—giant HII region—star cluster

scholarly journals The star formation histories of two Wolf-Rayet galaxies: NGC 1741 and He2-10. Two butterflies in a collection

1999 ◽  
Vol 193 ◽  
pp. 517-522
Author(s):  
Kelsey E. Johnson
Keyword(s):  
Star Formation ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Dwarf Galaxy ◽  
Broad Band ◽  
Star Clusters ◽  
Environmental Parameters ◽  
Super Star Clusters ◽  
Star Formation Histories ◽  
Compare And Contrast

In an effort to better understand how the properties of star formation in starburst galaxies depend on various environmental parameters, I present a comparison between two well-known WR galaxies: the interacting galaxy system NGC 1741 in the Hickson Compact Group 31, and the dwarf galaxy He2-10. The high spatial resolution of HST has allowed identification of a large number of starburst knots, or ‘super star clusters’ in these WR galaxies. Broad-band photometry and the latest stellar synthesis models are used to estimate the ages and masses of the super star clusters. The properties of the clusters are then used to compare and contrast the overall star-formation histories in the two WR galaxies.

scholarly journals Stellar feedback from a massive Super Star Cluster in the Antennae merger

2015 ◽  
Vol 12 (S316) ◽  
pp. 190-195 ◽  
Author(s):  
Cinthya N. Herrera ◽  
Francois Boulanger
Keyword(s):  
Star Formation ◽  
Radiation Pressure ◽  
Angular Resolution ◽  
Massive Stars ◽  
Star Cluster ◽  
Molecular Gas ◽  
Structure And Dynamics ◽  
Stellar Feedback ◽  
Formation Efficiency ◽  
Co Gas

AbstractStellar feedback from massive stars can unbind and disperse large amount of molecular gas, affecting the star formation efficiency. Based on ALMA and VLT observations in the Antennae galaxies we study a massive (~ 107 M⊙) and young (~ 3 Myr) SSC, B1, associated with compact molecular and ionized emission, which suggests that it is embedded in its parent cloud. However, we found contradictories and puzzling results on the structure and dynamics of the matter around the cluster, indicating that SSC B1 is not embedded in its parent cloud after all. We propose that radiation pressure was highly enhanced at the early stages of the SSC formation, disrupting the parent cloud in < 3 Myr. We show evidences of outflowing gas from the parent cloud in the more extended CO gas. Higher angular resolution observations are needed to validate this interpretation and to understand the origin and fate of the component seen to be associated with SSC B1.

scholarly journals CO observations as a diagnostic of possible environmental effects

2002 ◽  
Vol 206 ◽  
pp. 248-251
Author(s):  
Marcio A. G. Maia ◽  
Duilia de Mello ◽  
Tommy Wiklind
Keyword(s):  
Star Formation ◽  
Environmental Effects ◽  
Diagnostic Tool ◽  
Molecular Gas ◽  
Low Density ◽  
Physical Processes ◽  
Two Samples ◽  
Formation Efficiency ◽  
Very High ◽  
Co Observations

We have compared two samples of galaxies in very high and low density environments in order to study their physical properties and stablish any possible relation among them. This paper focus on the CO content as a diagnostic tool to examine galaxy properties such as the amount of molecular gas and the star formation efficiency. The similarities in star formation efficiency of the dense environments and the field galaxies suggest that the physical processes controling the formation of stars from the molecular gas are local rather than global.

scholarly journals Star clusters and young populations in the dwarf irregular galaxy Leo A

2018 ◽  
Vol 14 (S344) ◽  
pp. 139-142
Author(s):  
Rima Stonkutė ◽  
Marius Čeponis ◽  
Alina Leščinskaitė ◽  
Vladas Vansevičius
Keyword(s):  
Star Formation ◽  
Star Clusters ◽  
Star Formation History ◽  
Molecular Gas ◽  
Irregular Galaxy ◽  
Formation History ◽  
Low Metallicity ◽  
Low Mass ◽  
Density Map ◽  
Formation Efficiency

AbstractWe have studied young stellar populations and star clusters in the dwarf irregular galaxy Leo A using multicolor (B, V, R, I, Hα) photometry data obtained with the Subaru Suprime-Cam and two-color photometry results measured on archival HST/ACS F475W & F814W frames. The analysis of the main sequence (MS) and blue supergiant (BSG – “blue loop”) stars enabled us to study the star formation history in the Leo A galaxy during the last ~200 Myr. Also, we have discovered 5 low-mass (≲ 400 M⊙) star clusters within the ACS field. This finding, taking into account a low metallicity environment and a yet-undetected molecular gas in Leo A, constrains star formation efficiency estimates and scenarios. Inside the well known “hole” in the H i column density map (Hunter et al. 2012) we found a shock front (prominent in Hα), implying an unseen progenitor and reminding the “hole” problems widely discussed by Warren et al. (2011).

scholarly journals Super star clusters in Hii galaxies

2009 ◽  
Vol 5 (S266) ◽  
pp. 447-450
Author(s):  
Patricio Lagos ◽  
Eduardo Telles ◽  
E. R. Carrasco
Keyword(s):  
Spatial Distribution ◽  
Star Formation ◽  
Massive Star ◽  
Star Clusters ◽  
Dominant Mode ◽  
Star Cluster ◽  
The Galaxy ◽  
Super Star Clusters ◽  
Field Unit ◽  
The Masses

AbstractWe summarize our results based on observations with the NIRI camera on the Gemini North telescope of three Hii galaxies (Mrk 36, UM 408 and UM 461), obtained to identify and determine the ages and masses of the elementary components (the star cluster population) of the starburst regions in compact Hii galaxies. Our preliminary results indicate that the masses of the stellar clusters in these galaxies range from ~104 to ~106 M⊙, with associated ages of a few Myr. The most massive star clusters fall in the so-called super star cluster category. The identification of these clusters suggests that the formation and evolution of massive star clusters is the dominant mode of star formation in these galaxies. Their spatial distribution and ages seem to indicate that star formation is simultaneous over these timescales in some of our objects. We also review our recent description of the spatial distribution of physical conditions in the Hii galaxy UM 408 using the GMOS integral-field unit on Gemini South. The spatial distribution of the oxygen abundance does not show any significant variation or gradient across the galaxy on scales of hundreds of parsecs, within our observational uncertainties, confirming that this compact Hii galaxy, like other previously studied dwarf irregular galaxies, is chemically homogeneous.

scholarly journals Super Star Clusters in NGC 7673 and Mrk 8

2002 ◽  
Vol 207 ◽  
pp. 464-467
Author(s):  
N. Homeier ◽  
J.S. Gallagher
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Massive Star ◽  
Hubble Space Telescope ◽  
Star Clusters ◽  
Star Cluster ◽  
Population Synthesis ◽  
Massive Star Formation ◽  
Super Star Clusters ◽  
Intense Star Formation

We present an analysis of super star cluster populations using WFPC 2 on theHubble Space Telescopefor two starburst galaxies: NGC 7673 and Markarian 8. Both galaxies are luminious and have signatures of massive star formation, such as emission-line dominated optical spectra. Their optical appearances are highly disturbed, featuring prominent knots of intense star formation. Using HST F255W, F555W, and F814W images, we perform aperture photometry for a select sample of star clusters in different regions of each galaxy, and compare the results with evolutionary population synthesis models.

From global to local scales in galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 391-395
Author(s):  
Sebastian F. Sánchez ◽  
Carlos Lopez Cobá
Keyword(s):  
Star Formation ◽  
Spatial Scales ◽  
Bimodal Distribution ◽  
Spectroscopic Properties ◽  
Molecular Gas ◽  
Ionized Gas ◽  
Galaxy Surveys ◽  
Quenching Process ◽  
Formation Efficiency ◽  
Integral Field

AbstractWe summarize here some of the results reviewed recently by Sanchez (2020) comprising the advances in the comprehension of galaxies in the nearby universe based on integral field spectroscopic galaxy surveys. In particular we explore the bimodal distribution of galaxies in terms of the properties of their ionized gas, showing the connection between the star-formation (quenching) process with the presence (absence) of molecular gas and the star-formation efficiency. We show two galaxy examples that illustrates the well known fact that ionization in galaxies (and the processes that produce it), does not happen monolitically at galactic scales. This highlight the importance to explore the spectroscopic properties of galaxies and the evolutionary processes unveiled by them at different spatial scales, from sub-kpc to galaxy wide.

scholarly journals Disruption of giant molecular clouds and formation of bound star clusters under the influence of momentum stellar feedback

2019 ◽  
Vol 487 (1) ◽  
pp. 364-380 ◽  
Author(s):  
Hui Li ◽  
Mark Vogelsberger ◽  
Federico Marinacci ◽  
Oleg Y Gnedin
Keyword(s):  
Star Formation ◽  
Molecular Clouds ◽  
Star Clusters ◽  
Giant Molecular Clouds ◽  
Density Profiles ◽  
Stellar Feedback ◽  
Wide Range ◽  
Gas Removal ◽  
Formation Efficiency ◽  
Stellar Density

Abstract Energetic feedback from star clusters plays a pivotal role in shaping the dynamical evolution of giant molecular clouds (GMCs). To study the effects of stellar feedback on the star formation efficiency of the clouds and the dynamical response of embedded star clusters, we perform a suite of isolated GMC simulations with star formation and momentum feedback subgrid models using the moving-mesh hydrodynamics code Arepo. The properties of our simulated GMCs span a wide range of initial mass, radius, and velocity configurations. We find that the ratio of the final stellar mass to the total cloud mass, ϵint, scales strongly with the initial cloud surface density and momentum feedback strength. This correlation is explained by an analytic model that considers force balancing between gravity and momentum feedback. For all simulated GMCs, the stellar density profiles are systematically steeper than that of the gas at the epochs of the peaks of star formation, suggesting a centrally concentrated stellar distribution. We also find that star clusters are always in a sub-virial state with a virial parameter ∼0.6 prior to gas expulsion. Both the sub-virial dynamical state and steeper stellar density profiles prevent clusters from dispersal during the gas removal phase of their evolution. The final cluster bound fraction is a continuously increasing function of ϵint. GMCs with star formation efficiency smaller than 0.5 are still able to form clusters with large bound fractions.

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