scholarly journals Infrared helium emission lines from Cygnus X-3 suggesting a Wolf-Rayet star companion

Nature ◽  
1992 ◽  
Vol 355 (6362) ◽  
pp. 703-705 ◽  
Author(s):  
M. H. van Kerkwijk ◽  
P. A. Charles ◽  
T. R. Geballe ◽  
D. L. King ◽  
G. K. Miley ◽  
...  
Keyword(s):  
Emission Lines ◽  
Rayet Star ◽  
Helium Emission

scholarly journals Molecular gas around the Wolf-Rayet star WR 18 (WN4)

2003 ◽  
Vol 212 ◽  
pp. 732-733
Author(s):  
Anthony P. Marston
Keyword(s):  
Mass Loss ◽  
Optical Emission ◽  
Emission Lines ◽  
Molecular Gas ◽  
Evolved Stars ◽  
Ring Nebula ◽  
History Of ◽  
Optical Ring ◽  
Ring Nebulae ◽  
Rayet Star

Optically observed ring nebulae and H i cavities around Wolf-Rayet stars have enabled us to obtain information on the history of mass-loss associated with these massive evolved stars. However, such studies have left a number of unanswered questions regarding the amount of mass-loss and the conditions of the stars during a sequence of mass-loss phases. Here we discuss the molecular gas environments of the WR star WR 18, which has an associated optical ring nebula NGC 3199. Our observations show that significant amounts of molecular gas appear close to and associated with the star. Mapping of molecular CO near the star shows that molecular materials appear to substantially avoid areas of optical emission and, instead, form a distorted clumpy shell interior to NGC 3199. Molecular emission lines are broader than lines seen in the interstellar medium and suggest the shell is composed of ejecta. This is further corroborated by the enhanced abundances of molecules containing C, N and O. Implications of the observations for the evolution of WR 18 are discussed.

Detection of polarization structure across the emission lines of the Wolf-Rayet star HD 50896

1979 ◽  
Vol 231 ◽  
pp. L141 ◽  
Author(s):  
I. S. McLean ◽  
G. V. Coyne ◽  
S. J. J. E. Frecker ◽  
K. Serkowski
Keyword(s):  
Emission Lines ◽  
Polarization Structure ◽  
Rayet Star

scholarly journals Helium Emission Lines in the Type I[CLC]c[/CLC] Supernova 1999[CLC]cq[/CLC]

2000 ◽  
Vol 119 (5) ◽  
pp. 2303-2310 ◽  
Author(s):  
Thomas Matheson ◽  
Alexei V. Filippenko ◽  
Ryan Chornock ◽  
Douglas C. Leonard ◽  
Weidong Li
Keyword(s):  
Emission Lines ◽  
Type I ◽  
Helium Emission

scholarly journals New Models for Massive Star Populations in Young Starbursts: Summary of the Models and Applications

1999 ◽  
Vol 186 ◽  
pp. 285-285
Author(s):  
Daniel Schaerer ◽  
William D. Vacca
Keyword(s):  
Emission Line ◽  
Stellar Evolution ◽  
Massive Star ◽  
Optical Emission ◽  
Emission Lines ◽  
Evolutionary Synthesis ◽  
Stellar Spectra ◽  
New Models ◽  
Helium Emission ◽  
Line Strengths

Using the latest stellar evolution models, theoretical stellar spectra, and a compilation of observed emission line strengths from Wolf-Rayet (WR) stars, we have constructed evolutionary synthesis models for young starbursts (Schaerer & Vacca 1997; see also Schaerer 1996). We provide detailed predictions of UV and optical emission line strengths for both the WR stellar lines and the major nebular hydrogen and helium emission lines, as a function of several input parameters related to the starburst episode.

scholarly journals A New Search for Nebulae Surrounding Wolf-Rayet Stars

1982 ◽  
Vol 99 ◽  
pp. 463-468
Author(s):  
Joy N. Heckathorn ◽  
Frederick C. Bruhweiler ◽  
Theodore R. Gull
Keyword(s):  
Milky Way ◽  
Narrow Band ◽  
Interference Filter ◽  
Emission Lines ◽  
List Type ◽  
Type Number ◽  
Filamentary Structure ◽  
Line Survey ◽  
Ring Nebulae ◽  
Rayet Star

We have used the plate data from An Emission Line Survey of the Milky Way by Parker, Gull and Kirschner(1979) to make a new search for ring nebulae around Wolf-Rayet stars. The Survey consists of narrow-band interference filter direct imagery centered on the emission lines of Hα + [N II] at λ6570, [O III] at λ5007, and [S II] at λ6730. We have discovered at least five new ring nebulae. of the fifteen ring nebulae we were able to detect on the Survey, including our new discoveries, eleven were brighter in the [O III] bandpass than in the Hα + [N II] bandpass, and were filamentary in [O III]. All of the nebulosities we were able to detect were rated on the basis of three criteria: 1)Sharp, filamentary structure present in any or all bandpasses.2)Wolf-Rayet star centered in projected nebulosity, or, if off-center, the segment of the ring nearest the star proportionally brighter than the rest of the ring.3)Absence of any O stars within the nebulosity, or O star in off-centered position not adjacent to the brightest or sharpest portion of the ring.

scholarly journals Improving Predictions for Helium Emission Lines

1999 ◽  
Vol 514 (1) ◽  
pp. 307-324 ◽  
Author(s):  
Robert A. Benjamin ◽  
Evan D. Skillman ◽  
Derck P. Smits
Keyword(s):  
Emission Lines ◽  
Helium Emission

scholarly journals Possible Detection of X-Ray Emitting Circumstellar Material in the Synchrotron-dominated Supernova Remnant RX J1713.7−3946

2021 ◽  
Vol 923 (2) ◽  
pp. 187
Author(s):  
Dai Tateishi ◽  
Satoru Katsuda ◽  
Yukikatsu Terada ◽  
Fabio Acero ◽  
Takashi Yoshida ◽  
...  
Keyword(s):  
Supernova Remnant ◽  
Thermal Emission ◽  
Abundance Ratio ◽  
Emission Lines ◽  
Emission Model ◽  
X Ray ◽  
Circumstellar Material ◽  
Elemental Abundances ◽  
Reflection Grating ◽  
Rayet Star

Abstract We report on a discovery of an X-ray emitting circumstellar material (CSM) knot inside the synchrotron dominant supernova remnant RX J1713.7−3946. This knot was previously thought to be a Wolf–Rayet star (WR 85), but we realized that it is in fact ∼40″ away from WR 85, indicating no relation to WR 85. We performed high-resolution X-ray spectroscopy with the Reflection Grating Spectrometer (RGS) on board XMM-Newton. The RGS spectrum clearly resolves a number of emission lines, such as N Lyα, O Lyα, Fe xviii, Ne x, Mg xi, and Si xiii. The spectrum can be well represented by an absorbed thermal-emission model with a temperature of k B T e = 0.65 ± 0.02 keV. The elemental abundances are obtained to be N / H = 3.5 ± 0.8 N / H ⊙ , O / H = 0.5 ± 0.1 O / H ⊙ , Ne / H = 0.9 ± 0.1 Ne / H ⊙ , Mg / H = 1.0 ± 0.1 Mg / H ⊙ , Si / H = 1.0 ± 0.2 Si / H ⊙ , and Fe / H = 1.3 ± 0.1 Fe / H ⊙ . The enhanced N abundance with others being about the solar values allows us to infer that this knot is CSM ejected when the progenitor star evolved into a red supergiant. The abundance ratio of N to O is obtained to be N / O = 6.8 − 2.1 + 2.5 N / O ⊙ . By comparing this to those in outer layers of red supergiant stars expected from stellar evolution simulations, we estimate the initial mass of the progenitor star to be 15 M ⊙ ≲ M ≲ 20 M ⊙.

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