scholarly journals X-Ray Emission-Line Profiles of Three Early-Type Stars Observed with Chandra

2007 ◽  
Vol 59 (1) ◽  
pp. 237-244 ◽  
Author(s):  
Norimasa Yamamoto ◽  
Haruko Takano ◽  
Shunji Kitamoto ◽  
Takayoshi Kohmura
Keyword(s):  
Emission Line ◽  
Line Profiles ◽  
Early Type ◽  
X Ray ◽  
Early Type Stars

scholarly journals Chemical Abundances of Early Type Stars

1998 ◽  
Vol 188 ◽  
pp. 224-225
Author(s):  
S. Tanaka ◽  
S. Kitamoto ◽  
T. Suzuki ◽  
K. Torii ◽  
M.F. Corcoran ◽  
...  
Keyword(s):  
Surface Layer ◽  
Stellar Wind ◽  
Nuclear Reactions ◽  
X Rays ◽  
Early Type ◽  
Chemical Abundances ◽  
X Ray ◽  
Low Metallicity ◽  
Early Type Stars

X-rays from early-type stars are emitted by the corona or the stellar wind. The materials in the surface layer of early-type stars are not contaminated by nuclear reactions in the stellar inside. Therefore, abundance study of the early-type stars provides us an information of the abundances of the original gas. However, the X-ray observations indicate low-metallicity, which is about 0.3 times of cosmic abundances. This fact raises the problem on the cosmic abundances.

X‐Ray Emission from Early‐Type Stars in the Orion Nebula Cluster

2005 ◽  
Vol 160 (2) ◽  
pp. 557-581 ◽  
Author(s):  
B. Stelzer ◽  
E. Flaccomio ◽  
T. Montmerle ◽  
G. Micela ◽  
S. Sciortino ◽  
...  
Keyword(s):  
Orion Nebula ◽  
Early Type ◽  
X Ray ◽  
Early Type Stars

Emission-line Stars and Early-type Stars with Gaia

2010 ◽  
Vol 45 ◽  
pp. 373-376 ◽  
Author(s):  
R. Blomme ◽  
Y. Frémat ◽  
A. Lobel ◽  
C. Martayan
Keyword(s):  
Emission Line ◽  
Early Type ◽  
Early Type Stars

Problems in the Formation of Neutral Helium Lines in Early Type Stars

1970 ◽  
Vol 1 (7) ◽  
pp. 326-328
Author(s):  
R. W. Simpson
Keyword(s):  
Absorption Coefficient ◽  
Electron Scattering ◽  
Growth Analysis ◽  
Line Profiles ◽  
Early Type ◽  
Line Absorption ◽  
Early Type Stars ◽  
Made In ◽  
The Continuum

The aim of this work is to investigate certain assumptions that have been made in calculating line profiles and equivalent widths of neutral helium lines in early type stars. The effect of electron scattering on the continuum flux is investigated and a curve of growth analysis carried out to study this effect. The theories involved in calculating the line absorption coefficient are also investigated.

Hβ Line Profiles for Rapidly Rotating Early- Type Stars.

1965 ◽  
Vol 70 ◽  
pp. 320
Author(s):  
George W., II Collins ◽  
J. Patrick Harrington
Keyword(s):  
Line Profiles ◽  
Early Type ◽  
Early Type Stars

scholarly journals X-ray selected Wolf-Rayet stars: The discovery of Th35-42 and prospects for future X-ray surveys

1995 ◽  
Vol 163 ◽  
pp. 481-485
Author(s):  
S. Mereghetti ◽  
T. Belloni ◽  
F. Haberl ◽  
W. Voges
Keyword(s):  
Neutron Star ◽  
Emission Line ◽  
Optical Spectroscopy ◽  
Early Type ◽  
X Ray ◽  
Sky Survey ◽  
Colliding Winds ◽  
Einstein Observatory

The X-ray source 1E 1024.0-5732, serendipitously discovered with the Einstein Observatory, was previously interpreted as a rapidly spinning neutron star, accreting matter from its massive early-type companion, the emission-line star Th35-42. However, new ROSAT data do not support the presence of a neutron star in this source. A more likely scenario, also indicated by recent optical spectroscopy, involves X-ray emission from the colliding winds of a WR+O binary. Surprisingly, this star remained unnoticed during an extensive optical search for new Wolf-Rayet stars, carried out in this region of sky. Stimulated by the discovery of this first X-ray selected WR star, we have undertaken a search for similar objects in the data from the ROSAT All Sky Survey.

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