Simulations of the line-driven instability in magnetic hot star winds
arXiv:2110.05302 · doi:10.1051/0004-6361/202142175
Abstract
Line-driven winds of hot, luminous stars are intrinsically unstable due to the line-deshadowing instability (LDI). In non-magnetic hot stars, the LDI leads to the formation of an inhomogeneous wind consisting of small-scale, spatially separated clumps that can have great effects on observational diagnostics. However, for magnetic hot stars the LDI generated structures, wind dynamics, and effects on observational diagnostics have not been directly investigated so far. We investigated the non-linear development of LDI generated structures and dynamics in a magnetic line-driven wind of a typical O-supergiant. We employed two-dimensional axisymmetric magnetohydrodynamic (MHD) simulations of the LDI using the Smooth Source Function approximation for evaluating the assumed one-dimensional line force. To facilitate the interpretation of these magnetic models, they were compared with a corresponding non-magnetic LDI simulation as well as a magnetic simulation neglecting the LDI. A central result obtained is that the wind morphology and wind clumping properties change strongly with increasing wind-magnetic confinement. Most notably, in magnetically confined flows, the LDI leads to large-scale, shellular sheets ('pancakes') that are quite distinct from the spatially separate, small-scale clumps in non-magnetic line-driven winds. We discuss the impact of these findings for observational diagnostic studies and stellar evolution models of magnetic hot stars.
14 pages, 7 figures, accepted for publication in A&A
References in corpus (33)
- Mass loss from hot massive stars
- CMasher: Scientific colormaps for making accessible, informative and 'cmashing' plots
- How mergers magnetise massive stars
- Bright OB stars in the Galaxy - III. Constraints on the radial stratification of the clumping factor in hot star winds from a combined Halpha, IR and radio analysis
- Dynamical Simulations of Magnetically Channeled Line-Driven Stellar Winds: II. The Effects of Field-Aligned Rotation
- Dynamical Simulations of Magnetically Channeled Line-Driven Stellar Winds: III. Angular Momentum Loss and Rotational Spindown
- The MiMeS survey of magnetism in massive stars: Magnetic analysis of the O-type stars
- Magnetic massive stars as progenitors of "heavy" stellar-mass black holes
- The MiMeS Survey of Magnetism in Massive Stars: CNO surface abundances of Galactic O stars
- A Rigid-Field Hydrodynamics approach to modeling the magnetospheres of massive stars
- Long-term evolution of a magnetic massive merger product
- The effects of surface fossil magnetic fields on massive star evolution: I. Magnetic field evolution, mass-loss quenching and magnetic braking
- New predictions for radiation-driven, steady-state mass-loss and wind-momentum from hot, massive stars. I. Method and first results
- Possible pair-instability supernovae at solar metallicity from magnetic stellar progenitors
- An `Analytic Dynamical Magnetosphere' formalism for X-ray and optical emission from slowly rotating magnetic massive stars
- Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) - I. First-light observations of known magnetic B and A stars
- The effects of surface fossil magnetic fields on massive star evolution: II. Implementation of magnetic braking in MESA and implications for the evolution of surface rotation in OB stars
- Empirical mass-loss rates and clumping properties of Galactic early-type O supergiants
- Theoretical wind clumping predictions of OB supergiants from line-driven instability simulations across the bi-stability jump
- Radial dependence of line profile variability in seven O9--B0.5 stars
- Stochastic light variations in hot stars from wind instability: Finding photometric signatures and testing against the TESS data
- Upper Mass-Loss Limits and Clumping in the Intermediate and Outer Wind Regions of OB stars
- Characterizing the turbulent porosity of stellar-wind structure generated by the line-deshadowing instability
- The vertical Na-O relation in the bulge globular cluster NGC 6553
- Discovery of Two Rare Rigidly-Rotating Magnetosphere Stars in the APOGEE Survey
- Magnetometry of a sample of massive stars in Carina
- Shock-heated radiation-driven outflows as a solution to the weak-wind problem of late O-type stars
- An infrared diagnostic for magnetism in hot stars
- Ultraviolet Line Profiles of Slowly Rotating Massive Star Winds Using the "Analytic Dynamical Magnetosphere" Formalism
- Effect of a magnetic field on massive star winds I: mass-loss and velocity for a dipole field
- A 3D short-characteristics method for continuum and line scattering problems in the winds of hot stars
- 3D MHD simulations and synthetic radio emission from an oblique rotating magnetic massive star
- Physics of mass loss in massive stars
Cited by in corpus (5)
- Method and new tabulations for flux-weighted line-opacity and radiation line-force in supersonic media
- Theoretical wind clumping predictions from 2D LDI models of O-star winds at different metallicities
- Ultraviolet Spectropolarimetric Diagnostics of Hot Star Magnetospheres
- Progress towards a 3D Monte Carlo radiative transfer code for outflow wind modelling
- Testing the Reliability of X-rays as a Tool for Constraining Mass-loss Rates of Hot Stars