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 metallicities towards Wolf-Rayet stars. In our simulations, the initial rotating velocities are taken as 0, 250, 500 and 650 km s${}^{-1}$, and the metallicities equal to 0.02, 0.014, 0.008, 0.006, 0.004 and 0.002. We show our rapid rotation models in the HR diagram compared with the observations. We find that the rotational mixing is less efficient at high metallicity, and these stars become Wolf-Rayet (WR) stars when the helium in their center is ignited. However, rapid rotating massive stars at low metallicity can easily evolve into WR stars due to the rotation resulted in chemically homogeneous evolution. This can explain the origin of single WR stars in galaxy at low metallicity. In our models, the observed SMC WR stars are consistent with the single-star evolution models. However at higher metallicities our single-star evolution models can only explain the luminous, hydrogen-rich WN stars and O stars (which are classified as WR stars previously).

arXiv comment13 pages, 4 figures, Accepted for publication in PASP

References in corpus (56)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• Discovery of the peculiar supernova 1998bw in the error box of GRB980425
• The Supernova -- Gamma-Ray Burst Connection
• Mass-loss predictions for O and B stars as a function of metallicity
• A very energetic supernova associated with the gamma-ray burst of 29 March 2003
• Presupernova Evolution of Rotating Massive Stars I: Numerical Method and Evolution of the Internal Stellar Structure
• Physical Properties of Wolf-Rayet Stars
• Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
• Rotating Massive Main-Sequence Stars I: Grids of Evolutionary Models and Isochrones
• Evolution of rapidly rotating metal-poor massive stars towards gamma-ray bursts
• The rotation rates of massive stars: the role of binary interaction through tides, mass transfer and mergers
• Stellar evolution with rotation XI: Wolf-Rayet star populations at different metallicities
• The effect of massive binaries on stellar populations and supernova progenitors
• Single star progenitors of long gamma-ray bursts I: Model grids and redshift dependent GRB rate
• Stellar evolution with rotation X: Wolf-Rayet star populations at solar metallicity
• V1309 Scorpii: merger of a contact binary
• Stellar evolution with rotation VII: Low metallicity models and the blue to red supergiant ratio in the SMC
• On the role of continuum-driven eruptions in the evolution of very massive stars and Population III stars
• The Galactic WN stars: Spectral analyses with line-blanketed model atmospheres versus stellar evolution models with and without rotation
• Sub-surface convection zones in hot massive stars and their observable consequences
• The VLT-FLAMES Tarantula Survey I: Introduction and observational overview
• Grids of stellar models with rotation II. WR populations and supernovae/GRB progenitors at Z = 0.014
• Rotational mixing in massive binaries: detached short-period systems
• Runaway stars as progenitors of supernovae and gamma-ray bursts
• Evolution and fate of very massive stars
• The most massive stars in the Arches cluster
• The Galactic WC stars: Stellar parameters from spectral analyses indicate a new evolutionary sequence
• Constraining the mass transfer in massive binaries through progenitor evolution models of Wolf-Rayet+O binaries
• The Wolf-Rayet stars in the Large Magellanic Cloud: A comprehensive analysis of the WN class
• Stellar and Wind Properties of LMC WC4 stars - A metallicity dependence for Wolf-Rayet mass-loss rates
• Stellar envelope inflation near the Eddington limit. Implications for the radii of Wolf-Rayet stars and luminous blue variables
• Fundamental properties of core-collapse Supernova and GRB progenitors: predicting the look of massive stars before death
• Which Massive stars are Gamma-Ray Burst Progenitors?
• Implications of the metallicity dependence of Wolf-Rayet winds
• Ionizing spectra of stars that lose their envelope through interaction with a binary companion: role of metallicity
• The effect of stellar evolution uncertainties on the rest-frame ultraviolet stellar lines of CIV and HeII in high-redshift Lyman-break galaxies
• Towards a better understanding of the evolution of Wolf-Rayet stars and Type Ib/Ic supernova progenitors
• Spectral Classification of O2-3.5If*/WN5-7 stars
• Wolf-Rayet stars in the Small Magellanic Cloud: I. Analysis of the single WN stars
• Wolf-Rayet stars in the Small Magellanic Cloud: II. Analysis of the binaries
• The age-metallicity relationship of the Large Magellanic Cloud field star population from wide-field Washington photometry
• Massive star evolution in close binaries:conditions for homogeneous chemical evolution
• The WR population predicted by massive single star and by massive binary evolution
• A Modern Search for Wolf-Rayet Stars in the Magellanic Clouds: First Results
• Wolf-Rayet stars in the Small Magellanic Cloud as testbed for massive star evolution
• The HD5980 multiple system: Masses and evolutionary status
• Helium Stars: Towards an Understanding of Wolf-Rayet Evolution
• Evidence for quasi-chemically homogeneous evolution of massive stars up to solar metallicity
• The Quintuplet Cluster II. Analysis of the WN stars
• The Evolution and Physical Parameters of WN3/O3s: a New Type of Wolf-Rayet Star
• The VLT-FLAMES Tarantula Survey II: R139 revealed as a massive binary system
• Spin Angular Momentum Evolution of the Long Period Algols
• Another single hydrogen-rich Wolf-Rayet star in the SMC?
• Effects of the core-collapse supernova ejecta impact on a rapidly rotating massive companion star

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• The Galactic WC and WO stars: The impact of revised distances from Gaia DR2 and their role as massive black hole progenitors
• Pathways for producing binary black holes with large misaligned spins in the isolated formation channel
• Low-metallicity massive single stars with rotation. II. Predicting spectra and spectral classes of chemically-homogeneously evolving stars
• Signatures of Rapidly Rotating Stars with Chemically Homogeneous Evolution in the First Galaxies
• The population synthesis of Wolf-Rayet stars involving binary merger channels
• Hydrogen-free Wolf-Rayet stars: Helium stars with envelope-inflation structure and rotation
• Heavy element contributions of rotating massive stars to Interstellar Medium
• Impact of accretion-induced chemically homogeneous evolution on stellar and compact binary populations
• An Alternative Formation Scenario for Uranium-rich Giants: Engulfing a Earth-like Planet
• Signatures of spin precession and nutation in isolated black-hole binaries