Radiation-Driven Wind Hydrodynamics of Massive Stars: A Review

Abstract

Mass loss from massive stars plays a determining role in their evolution through the upper Hertzsprung-Russell diagram. The hydrodynamic theory that describes their steady-state winds is the line-driven wind theory (m-CAK). From this theory, the mass loss rate and the velocity profile of the wind can be derived, and estimating these properly will have a profound impact on quantitative spectroscopy analyses from the spectra of these objects. Currently, the so-called beta-law, which is an approximation for the fast solution, is widely used instead of m-CAK hydrodynamics, and when the derived value is beta greater than 1.2, there is no hydrodynamic justification for these values. This review focuses on (1) a detailed topological analysis of the equation of motion (EoM), (2) solving the EoM numerically for all three different (fast and two slow) wind solutions, (3) deriving analytical approximations for the velocity profile via the LambertW function and (4) presenting a discussion of the applicability of the slow solutions.

Published in Galaxies Journal (33 pages, 18 figures)

References in corpus (15)

• Mass loss from hot massive stars
• Bright OB stars in the Galaxy IV. Stellar and wind parameters of early to late B supergiants
• Quantitative Spectroscopy of 24 A supergiants in the Sculptor galaxy NGC 300: Flux weighted gravity luminosity relationship, metallicity and metallicity gradient
• Statistical properties of a sample of periodically variable B-type supergiants - Evidence for opacity-driven gravity-mode oscillations
• Metallicity-dependent wind parameter predictions for OB stars
• A consistent solution for the velocity field and mass-loss rate of massive stars
• X-Shooting ULLYSES: Massive stars at low metallicity. III. Terminal wind speeds of ULLYSES massive stars
• Intensity interferometry of P Cygni in the H$\alpha$ emission line: towards distance calibration of LBV supergiant stars
• An Updated Formalism For Line-Driven Radiative Acceleration and Implications for Stellar Mass Loss
• Self-consistent solutions for line-driven winds of hot massive stars. The m-CAK procedure
• Method and new tabulations for flux-weighted line-opacity and radiation line-force in supersonic media
• New self-consistent wind parameters fitting optical spectra of O-type stars observed with HERMES spectrograph
• $\Omega$-Slow Solutions and Be Star Disks
• Line-Driven Winds Revisited in the Context of Be Stars: $\Omega$-slow Solutions with High $k$ Values
• Analytical Solutions for Radiation-Driven Winds in Massive Stars. I: The Fast Regime

Cited by in corpus (1)

• Classical Be stars