On the bipolarity of Wolf-Rayet nebulae

Abstract

Wolf-Rayet stars are amongst the rarest but also most intriguing massive stars. Their extreme stellar winds induce famous multi-wavelength circumstellar gas nebulae of various morphologies, spanning from circles and rings to bipolar shapes. This study is devoted to the investigation of the formation of young, asymmetric Wolf-Rayet gas nebulae and we present a 2.5-dimensional magneto-hydrodynamical toy model for the simulation of Wolf-Rayet gas nebulae generated by wind-wind interaction. Our method accounts for stellar wind asymmetries, rotation, magnetisation, evolution and mixing of materials. It is found that the morphology of the Wolf-Rayet nebulae of blue supergiant ancestors is tightly related to the wind geometry and to the stellar phase transition time interval, generating either a broadened peanut-like or a collimated jet-like gas nebula. Radiative transfer calculations of our Wolf-Rayet nebulae for dust infrared emission at 24 $\mu$m show that the projected diffuse emission can appear as oblate, bipolar, ellipsoidal or ring structures. Important projection effects are at work in shaping observed Wolf-Rayet nebulae. This might call a revision of the various classifications of Wolf-Rayet shells, which are mostly based on their observed shape. Particularly, our models question the possibility of producing pre-Wolf-Rayet wind asymmetries, responsible for bipolar nebulae like NGC 6888, within the single red supergiant evolution channel scenario. We propose that bipolar Wolf-Rayet nebulae can only be formed within the red supergiant scenario by multiple/merged massive stellar systems, or by single high-mass stars undergoing additional, e.g. blue supergiant, evolutionary stages prior to the Wolf-Rayet phase.

18 pages, 10 figures

References in corpus (33)

• The Supernova -- Gamma-Ray Burst Connection
• PLUTO: a Numerical Code for Computational Astrophysics
• Physical Properties of Wolf-Rayet Stars
• Pre-Supernova Evolution of Massive Single and Binary Stars
• The Galactic WN stars: Spectral analyses with line-blanketed model atmospheres versus stellar evolution models with and without rotation
• The Galactic WC stars: Stellar parameters from spectral analyses indicate a new evolutionary sequence
• The VLT-FLAMES Tarantula Survey XVII. Physical and wind properties of massive stars at the top of the main sequence
• (Sub)stellar companions shape the winds of evolved stars
• The Evolution of Supernovae in Circumstellar Wind Bubbles II: Case of a Wolf-Rayet star
• Forming spectroscopic massive proto-binaries by disk fragmentation
• Computing the dust distribution in the bowshock of a fast moving, evolved star
• Multiple ring nebulae around blue supergiants
• The close circumstellar environment of Betelgeuse - V. Rotation velocity and molecular envelope properties from ALMA
• Forming a constant density medium close to long gamma-ray bursts
• Interacting supernovae from photoionization-confined shells around red supergiant stars
• Double bow shocks around young, runaway red supergiants: application to Betelgeuse
• Simulating the formation of $\eta$ Carinae's surrounding nebula through unstable triple evolution and stellar merger-induced eruption
• An X-ray Survey of Wolf-Rayet Stars in the Magellanic Clouds. I. The Chandra ACIS Dataset
• Constraints on gamma-ray burst and supernova progenitors through circumstellar absorption lines. (II): Post-LBV Wolf-Rayet stars
• On the Diversity of M-Star Astrospheres and the Role of Galactic Cosmic Rays Within
• WISE morphological study of Wolf-Rayet nebulae
• MHD-shock structures of astrospheres: $\lambda$ Cephei-like astrospheres
• Wind nebulae and supernova remnants of very massive stars
• 3D MHD astrospheres: applications to IRC-10414 and Betelgeuse
• Non-thermal radio supernova remnants of exiled Wolf-Rayet stars
• Palomar/TripleSpec observations of {\it Spitzer}/MIPSGAL~24\mic\ circumstellar shells: unveiling the nature of their central sources
• A latitude-dependent wind model for Mira's cometary head
• Investigating Particle Acceleration in the Wolf-Rayet Bubble G2.4+1.4
• Optical spectroscopy of the blue supergiant Sk-69 279 and its circumstellar shell with SALT
• On the ring nebulae around runaway Wolf-Rayet stars
• The nature of the companion in the Wolf-Rayet system EZ Canis Majoris
• Tracing back the evolution of the candidate LBV HD168625
• Herschel-PACS Measurements of Nitrogen Enrichment in Nebulae around Wolf-Rayet Stars

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• Rectangular core-collapse supernova remnants: application to Puppis A
• Mixing of materials in magnetised core-collapse supernova remnants
• Ionization-Gasdynamic Simulations of Wind-Blown Nebulae around Massive Stars
• Particle acceleration, escape and non-thermal emission from core-collapse supernovae inside non-identical wind-blown bubbles