scholarly journals Clusters in Extragalactic HII Regions and their Modelling

2002 ◽  
Vol 207 ◽  
pp. 428-438
Author(s):  
Rosa María González Delgado
Keyword(s):  
Hii Regions ◽  
Starburst Galaxies ◽  
Stellar Clusters ◽  
Stellar Content ◽  
Evolutionary State ◽  
Optical Wavelengths

This review deals with properties of very young (≤ 10–20 Myr) stellar clusters which are in the nebular phase and are embedded in photoionized regions (classical extragalactic HII regions (RHIIs) or starburst galaxies). Based on the analysis of the integrated light of these clusters at the UV and optical wavelengths, different techniques are discussed that allow to estimate in consistent the stellar content and the evolutionary state of the ionizing clusters. Figures illustrating this contribution can be found in: http://www.iaa.csic.es/∼rosa/

Constraining the Galactic Structure with Stellar Clusters in Obscured Hii Regions

2009 ◽  
pp. 321-326
Author(s):  
M. Messineo ◽  
M. Petr-Gotzens ◽  
K. M. Menten ◽  
F. Schuller ◽  
H. J. Habing
Keyword(s):  
Hii Regions ◽  
Galactic Structure ◽  
Stellar Clusters

scholarly journals A 12CO Survey of the LMC with NANTEN

1999 ◽  
Vol 190 ◽  
pp. 61-66
Author(s):  
Y. Fukui ◽  
R. Abe ◽  
A. Hara ◽  
T. Hayakawa ◽  
S. Kato ◽  
...  
Keyword(s):  
Molecular Clouds ◽  
Cluster Formation ◽  
Hii Regions ◽  
Stellar Clusters ◽  
Giant Molecular Clouds

We have made a 12CO(J = 1−0) survey of the LMC with NANTEN. A sample of 55 giant molecular clouds has been identified and comparisons with stellar clusters, HII regions and SNRs are presented. The connection between the clouds and cluster formation is discussed.

scholarly journals The Youngest Star-Forming Regions in Galaxies: Giant Compact HII Regions and Protoglobular Clusters?

2001 ◽  
Vol 205 ◽  
pp. 224-227
Author(s):  
Jean L. Turner
Keyword(s):  
Dwarf Galaxy ◽  
Hii Regions ◽  
Starburst Galaxies ◽  
Mid Infrared ◽  
Infrared Observations ◽  
Star Forming ◽  
Bolometric Luminosity ◽  
Star Forming Regions ◽  
Young Clusters ◽  
Compact Hii Regions

Subarcsecond radio and infrared observations reveal a class of luminous, obscured, optically thick HII regions associated with extremely large young clusters in nearby starburst galaxies. VLA images show bright radio nebulae with ne ∼ 104 cm−3, densities characteristic of young Galactic compact HII regions. Excitation of the nebulae requires the presence of several thousand O stars within regions of 1-10 pc extent, corresponding to clusters containing 105–106 stars. The compact nebulae are also bright in the mid-infrared, and can for significant fractions of not only the total IR luminosity, but also the total bolometric luminosity, of the parent galaxies. The prototype for these “supernebulae” is the large, obscured cluster in the dwarf galaxy NGC 5253.

HII regions and young star clusters in the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 207-208
Author(s):  
Myung Gyoon Lee
Keyword(s):  
Main Sequence ◽  
Star Clusters ◽  
Hii Regions ◽  
Young Star ◽  
Magellanic Clouds ◽  
Stellar Content ◽  
Ccd Photometry ◽  
Luminosity Functions ◽  
Young Star Clusters ◽  
Mass Functions

Using U BV CCD photometry, the stellar content of HII regions and young star clusters in the Magellanic Clouds has been studied: (1) the reddenings have been determined, and ages of OB associations and young star clusters have been measured; (2) the stellar initial mass functions have been determined by using the main-sequence luminosity functions; and (3) U BV CCD surface photometry of nine young star clusters has been obtained and their structural properties investigated.

scholarly journals Radio Recombination Lines from Starburst Galaxies: High and Low Density Ionized Gas

2002 ◽  
Vol 199 ◽  
pp. 243-244
Author(s):  
N.R. Mohan ◽  
K.R. Anantharamaiah ◽  
W.M. Goss
Keyword(s):  
Flux Density ◽  
Hii Regions ◽  
Starburst Galaxies ◽  
High Density ◽  
The Other ◽  
Low Density ◽  
Ionized Gas ◽  
Density Measurements ◽  
Radio Recombination Lines ◽  
Upper Limits

Radio recombination lines (RRL) at 8 GHz and 15 GHz detected from four starburst galaxies are shown to arise in compact high density HII regions, which are undetectable below ∼4 GHz. Detection of an RRL at 1.4 GHz towards one galaxy and upper limits in the other three are consistent with the presence of an equal amount of low density diffuse gas. Continuum flux density measurements using the GMRT will be important in constraining the properties of the diffuse gas.

scholarly journals Massive Stars in the Tarantula Nebula: A Rosetta Stone for Extragalactic Supergiant HII Regions

Galaxies ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 88 ◽  
Author(s):  
Paul A. Crowther
Keyword(s):  
Massive Stars ◽  
Hii Regions ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
High Mass ◽  
Stellar Content ◽  
X Ray ◽  
Star Forming ◽  
Rosetta Stone ◽  
The Individual

A review of the properties of the Tarantula Nebula (30 Doradus) in the Large Magellanic Cloud is presented, primarily from the perspective of its massive star content. The proximity of the Tarantula and its accessibility to X-ray through radio observations permit it to serve as a Rosetta Stone amongst extragalactic supergiant HII regions since one can consider both its integrated characteristics and the individual properties of individual massive stars. Recent surveys of its high mass stellar content, notably the VLT FLAMES Tarantula Survey (VFTS), are reviewed, together with VLT/MUSE observations of the central ionizing region NGC 2070 and HST/STIS spectroscopy of the young dense cluster R136, provide a near complete Hertzsprung-Russell diagram of the region, and cumulative ionizing output. Several high mass binaries are highlighted, some of which have been identified from a recent X-ray survey. Brief comparisons with the stellar content of giant HII regions in the Milky Way (NGC 3372) and Small Magellanic Cloud (NGC 346) are also made, together with Green Pea galaxies and star forming knots in high-z galaxies. Finally, the prospect of studying massive stars in metal poor galaxies is evaluated.

scholarly journals Anatomy of Starbursts in Extragalactic Giant HII Regions: M51 Case Study

2012 ◽  
Vol 8 (S292) ◽  
pp. 329-329
Author(s):  
Jessica Marie Evans ◽  
You-Hua Chu
Keyword(s):  
Star Formation ◽  
Hubble Space Telescope ◽  
Hii Regions ◽  
Physical Structure ◽  
Stellar Content ◽  
Hii Region ◽  
Depth Analysis ◽  
Multi Wavelength ◽  
Long Time ◽  
Photometric Measurements

AbstractExtragalactic giant HII regions (EGHRs) are sites of active, concentrated star formation, and thus provide excellent labs to analyze the starburst phenomenon. Although they have been known for a long time, ground-based observations cannot resolve the physical structures and stellar content of EGHRs. The high resolution and sensitivity of Hubble Space Telescope (HST) are ideal for detailed studies of EGHRs. We have searched the Hubble Legacy Archives (HLA) and found 17 nearby galaxies, within ∼15 Mpc, with Hα and continuum images; to determine the best methods for analyzing these data, we perform an in-depth analysis of the EGHRs in M51. M51 is a face-on spiral galaxy ∼8.4 Mpc away, with well-resolved multi-wavelength observations in the HLA. We sample the 25 most luminous HII regions in M51, many of which are bonafide EGHRs with an H-alpha luminosity > 1039 ergs s−1. We use the Hα image to study the distribution and physical structure of the gas in each HII region and determine its Hα luminosity and required ionizing flux. We use the continuum images to determine whether super stellar clusters (SSCs) are found in these HII regions, and use photometric measurements to determine the mass and age spread of the resolved stellar population. These are then compared with the interstellar structures. The results help us provide the groundwork for studying EGHRs in multiple galaxies and elucidate the starburst phenomenon by investigating questions such as: What role does environment play in the formation of EGHRs? How do EGHRs evolve? How does star formation proceed in an EGHR?

Stellar content and kinematics of starburst galaxies

1997 ◽  
Author(s):  
Rosa M. González Delgado ◽  
Claus Leitherer ◽  
Timothy Heckman
Keyword(s):  
Starburst Galaxies ◽  
Stellar Content

scholarly journals Star Formation, Giant Hii Regions and Spiral Structure

1986 ◽  
Vol 7 ◽  
pp. 531-538
Author(s):  
Michael Rosa
Keyword(s):  
Star Formation ◽  
Title I ◽  
Spiral Structure ◽  
Hii Regions ◽  
Stellar Content ◽  
Recent Developments ◽  
Short Time

The three topics outlined in the title I have been given for this contribution are each far too complex to be thoroughly reviewed in the short time available. Instead of trying to duplicate the relevant (28, 34, 35) Commission Reports in the Transactions of the IAU (R.M. West 1985), I shall review only briefly current results on the stellar content of giant HII regions and then continue towards recent developments of our ideas about the mutual interrelation of galaxy wide star formation and spiral structure. The goal is to emphasize the simultaneous need for descriptions of details and unifying approaches.

Sign in / Sign up

Export Citation Format

Share Document