Helium Stars: Towards an Understanding of Wolf-Rayet Evolution

@article{McClelland2016HeliumST,
  title={Helium Stars: Towards an Understanding of Wolf-Rayet Evolution},
  author={L. McClelland and J. Eldridge},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2016},
  volume={459},
  pages={1505-1518}
}
Wolf-Rayet (WR) stars are massive stars that have lost most or all of their hydrogen via powerful stellar winds. Recent observations have indicated that hydrogen-free WR stars have cooler temperatures than those predicted by current evolutionary models. To investigate how varying mass-loss rate affects WR evolution, we have created a grid of pure helium star models. We compare our results with Galactic and LMC WR observations and show that the temperature ranges of observed WR stars can be… Expand
Towards a better understanding of the evolution of Wolf–Rayet stars and Type Ib/Ic supernova progenitors
Hydrogen-deficient Wolf-Rayet (WR) stars are potential candidates of Type Ib/Ic supernova (SN Ib/Ic) progenitors and their evolution is governed by mass loss. Stellar evolution models with the mostExpand
Helium stars: Towards an understanding of Wolf–Rayet evolution
Abstract Recent observational modelling of the atmospheres of hydrogen-free Wolf–Rayet stars have indicated that their stellar surfaces are cooler than those predicted by the latest stellar evolutionExpand
A Study of Wolf-Rayet Stars Formed VIA Chemically Homogeneous Evolution
Abstract Using the stellar evolution code—Modules for Experiments in Stellar Astrophysics (MESA)—we investigate the evolution of massive stars with different rotational velocities and metallicitiesExpand
Helium Star Models with Optically Thick Winds: Implications for the Internal Structures and Mass-loss Rates of Wolf–Rayet Stars
We construct helium (He) star models with optically thick winds and compare them with the properties of Galactic Wolf–Rayet (WR) stars. Hydrostatic He-core solutions are connected smoothly toExpand
The Galactic WC and WO stars: The impact of revised distances from Gaia DR2 and their role as massive black hole progenitors
Wolf-Rayet stars of the carbon sequence (WC stars) are an important cornerstone in the late evolution of massive stars before their core collapse. As core-helium burning, hydrogen-free objects withExpand
Predicting the nature of supernova progenitors
  • J. Groh
  • Physics, Medicine
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2017
TLDR
Recent efforts to predict the nature of stars before death by performing coupled stellar evolution and atmosphere modelling of single stars in the pre-SN stage are reviewed, and the detectability of SN Ibc progenitors is assessed. Expand
Wolf–Rayet stars, black holes and the first detected gravitational wave source
Abstract The recently discovered burst of gravitational waves GW150914 provides a good new chance to verify the current view on the evolution of close binary stars. Modern population synthesis codesExpand
Supernovae from massive stars with extended tenuous envelopes
Massive stars with a core-halo structure are interesting objects for stellar physics and hydrodynamics. Using simulations for stellar evolution, radiation hydrodynamics, and radiative transfer, weExpand
Core-collapse supernova progenitor constraints using the spatial distributions of massive stars in local galaxies
We study the spatial correlations between the H$\alpha$ emission and different types of massive stars in two local galaxies, the Large Magellanic Cloud (LMC) and Messier 33. We compare these toExpand
Ionizing spectra of stars that lose their envelope through interaction with a binary companion: role of metallicity
Understanding ionizing fluxes of stellar populations is crucial for various astrophysical problems including the epoch of reionization. Massive short-lived Wolf-Rayet stars are generally consideredExpand
...
1
2
3
...

References

SHOWING 1-10 OF 54 REFERENCES
Implications of the metallicity dependence of Wolf-Rayet winds
Aims. Recent theoretical predictions for the winds of Wolf-Rayet stars indicate that their mass-loss rates scale with the initial stellar metallicity in the local Universe. We aim to investigate howExpand
Are luminous and metal-rich Wolf-Rayet stars inflated?
Aims. We investigate the influence of metallicity and stellar wind mass loss on the radius of Wolf-Rayet stars. Methods. We have calculated chemically homogeneous models of Wolf-Rayet stars of 10 toExpand
Stellar evolution with rotation XI. Wolf-Rayet star populations at different metallicities
Grids of models of massive stars (M ≥ 20 M� ) with rotation are computed for metallicities Z ranging from that of the Small Magellanic Cloud (SMC) to that of the Galactic Centre. The hydrostaticExpand
The Wolf-Rayet stars in the Large Magellanic Cloud - A comprehensive analysis of the WN class
Context. Massive stars, although being important building blocks of galaxies, are still not fully understood. This especially holds true for Wolf-Rayet (WR) stars with their strong mass loss, whoseExpand
The effect of massive binaries on stellar populations and supernova progenitors
We compare our latest single and binary stellar model results from the Cambridge stars code to several sets of observations. We examine four stellar population ratios: the number of blue to redExpand
Helium-star Mass Loss and Its Implications for Black Hole Formation and Supernova Progenitors
  • O. Pols, J. Dewi
  • Physics, Biology
  • Publications of the Astronomical Society of Australia
  • 2002
TLDR
The authors' models reach final masses well in excess of 10 M⊙, consistent with the observed masses of black holes in X-ray binaries, which resolves the discrepancy found with previously assumed high mass-loss rates between the final masses of stars which spend most of their helium-burning lifetime as Wolf-Rayet stars. Expand
The WR and O-type star population predicted by massive star evolutionary synthesis
Abstract Evolutionary calculations of massive single stars and of massive close binaries that we use in the population number synthesis (PNS) code are presented. Special attention is given to theExpand
CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN LONG-DURATION GAMMA-RAY BURSTS?
The discovery of supernovae associated with long-duration gamma-ray burst observations is primary evidence that the progenitors of these outbursts are massive stars. One of the principle mysteries inExpand
The Wolf-Rayet Population Predicted by Massive Single Star and Massive Binary Evolution
We discuss the differences between massive single star and massive close binary population number synthesis predictions of WR stars. We show that the WC/WN number ratio as function of metallicityExpand
The Galactic WC stars Stellar parameters from spectral analyses indicate a new evolutionary sequence
[Abridged] [...] AIMS: We aim to establish the stellar parameters and mass-loss rates of the Galactic WC stars. These data provide the empirical basis of studies of (i) the role of WC stars in theExpand
...
1
2
3
4
5
...