The Evolution of an H II Region during the Formation of the Exciting Star

1966 ◽  
Vol 146 ◽  
pp. 104 ◽  
Author(s):  
Peter O. Vandervoort
Keyword(s):  
Exciting Star ◽  
H Ii Region

scholarly journals 13CO(J = 1-0) Observations of the Orion Molecular Cloud

1987 ◽  
Vol 115 ◽  
pp. 149-150
Author(s):  
K. Sugitani ◽  
Y. Fukui
Keyword(s):  
Millimeter Wave ◽  
High Velocity ◽  
Molecular Cloud ◽  
High Velocity Resolution ◽  
H Ii Region ◽  
Co Emission

We present new 13CO(J = 1-0) measurements of the Orion molecular cloud. The data were taken with the 4-m millimeter-wave telescope of Nagoya University with a beamwidth of 2.7′. The high velocity resolution of 0.1 km s−1 employed has revealed significant details of the 13CO emission toward the H II region.

scholarly journals On the Nature of R 136, the Central Object of 30 Dor. A Comparison by the Galactic Cluster NGC 3603

1984 ◽  
Vol 108 ◽  
pp. 257-258
Author(s):  
Michael Rosa ◽  
Jorge Melnick ◽  
Preben Grosbol
Keyword(s):  
Core Region ◽  
H Ii Regions ◽  
Central Object ◽  
The Core ◽  
Dominant Component ◽  
Galactic Cluster ◽  
H Ii Region

The massive H II region NGC 3603 is the closest galactic counterpart to the giant LMC nebula 30 Dor. Walborn (1973) first compared the ionizing OB/WR clusters of the two H II regions and suggested that R 136, the unresolved luminous WR + 0 type central object of 30 Dor, might be a multiple system like the core region of NGC 3603. Suggestions that the dominant component of R 136, i.e. R 136A, might be either a single or a very few supermassive and superluminous stars (Schmidt-Kaler and Feitzinger 1982, Savage et al. 1983) have recently been disputed by Moffat and Seggewiss (1983) and Melnick (1983), who have presented spectroscopic and photometric evidence to support the hypothesis of an unresolved cluster of stars. We have extended Walborn's original comparison of the apparent morphology of the two clusters by digital treatment of the images to simulate how the galactic cluster would look like if it were located in the LMC

scholarly journals Three generations of stars: a possible case of triggered star formation

2020 ◽  
Vol 496 (1) ◽  
pp. 870-874
Author(s):  
M B Areal ◽  
A Buccino ◽  
S Paron ◽  
C Fariña ◽  
M E Ortega
Keyword(s):  
Star Formation ◽  
Young Stellar Objects ◽  
H Ii Regions ◽  
Stellar Objects ◽  
Three Generations ◽  
The North ◽  
Western Border ◽  
H Ii Region ◽  
New Generation ◽  
North Western

ABSTRACT Evidence for triggered star formation linking three generations of stars is difficult to assemble, as it requires convincingly associating evolved massive stars with H ii regions that, in turn, would need to present signs of active star formation. We present observational evidence for triggered star formation relating three generations of stars in the neighbourhood of the star LS II +26 8. We carried out new spectroscopic observations of LS II +26 8, revealing that it is a B0 III-type star. We note that LS II +26 8 is located exactly at the geometric centre of a semi-shell-like H ii region complex. The most conspicuous component of this complex is the H ii region Sh2-90, which is probably triggering a new generation of stars. The distances to LS II +26 8 and to Sh2-90 are in agreement (between 2.6 and 3 kpc). Analysis of the interstellar medium on a larger spatial scale shows that the H ii region complex lies on the north-western border of an extended H2 shell. The radius of this molecular shell is about 13 pc, which is in agreement with what an O9 V star (the probable initial spectral type of LS II +26 8 as inferred from evolutive tracks) can generate through its winds in the molecular environment. In conclusion, the spatial and temporal correspondences derived in our analysis enable us to propose a probable triggered star formation scenario initiated by the evolved massive star LS II +26 8 during its main-sequence stage, followed by stars exciting the H ii region complex formed in the molecular shell, and culminating in the birth of young stellar objects around Sh2-90.

scholarly journals A high-excitation optically obscured H II region in the nucleus of NGC 5253

1982 ◽  
Vol 199 (1) ◽  
pp. 31P-35P ◽  
Author(s):  
D. K. Aitken ◽  
P. F. Roche ◽  
M. C. Allen ◽  
M. M. Phillips
Keyword(s):  
High Excitation ◽  
H Ii Region

scholarly journals MOPRA CO OBSERVATIONS OF THE BUBBLE H II REGION RCW 120

2015 ◽  
Vol 800 (2) ◽  
pp. 101 ◽  
Author(s):  
L. D. Anderson ◽  
L. Deharveng ◽  
A. Zavagno ◽  
P. Tremblin ◽  
V. Lowe ◽  
...  
Keyword(s):  
H Ii Region ◽  
Co Observations

scholarly journals starbench: the D-type expansion of an H ii region

2015 ◽  
Vol 453 (2) ◽  
pp. 1324-1343 ◽  
Author(s):  
T. G. Bisbas ◽  
T. J. Haworth ◽  
R. J. R. Williams ◽  
J. Mackey ◽  
P. Tremblin ◽  
...  
Keyword(s):  
H Ii Region

A study of rapid expanding H II region RCW 89

2008 ◽  
Author(s):  
Y. Yatsu ◽  
N. Kawai ◽  
J. Kataoka ◽  
W. Brinkmann ◽  
C. Bassa ◽  
...  
Keyword(s):  
H Ii Region
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