Stability Analysis of Strange-Modes in Hot Massive Stars with Time-Dependent Convection

Abstract

We carry out a nonadiabatic analysis of strange-modes in hot massive stars with time-dependent convection (TDC). In envelopes of such stars, convective luminosity is not so dominant as that in envelopes of stars in the redder side of the classical instability strip. Around the Fe opacity bump, however, convection non-negligibly contributes to energy transfer. Indeed, instability of modes excited at the Fe bump is likely to be suppressed with TDC compared with the case of adopting the frozen-in convection approximation. But we make sure that unstable strange-modes certainly appear in hot massive stars even by taking into account TDC. We also examine properties of the strange-mode instability, which is related to destabilization of strange-modes without adiabatic counterparts. In this type of instability, the phase lag between density and pressure varies from 0 to $180^{\circ }$ in an excitation zone unlike the case of the $\kappa$-mechanism. In addition, we confirm by comparing models with $Z=0$ and $Z=0.02$ that dominance of radiation pressure is important for this type of instability.

arXiv comment9 pages, 16 figures, accepted by Publications of the Astronomical Society of Japan

References in corpus (15)

• The chemical composition of the Sun
• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Grids of stellar models with rotation - I. Models from 0.8 to 120 Msun at solar metallicity (Z = 0.014)
• The Nucleosynthetic Signature of Population III
• The Formation of the First Star in the Universe
• First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
• Forming the First Stars in the Universe: The Fragmentation of Primordial Gas
• Nucleosynthesis of Zinc and Iron-Peak Elements in Pop III Type II Supernovae : Comparison with abundances of Very Metal-Poor Halo Stars
• Atmospheric NLTE-Models for the Spectroscopic Analysis of Blue Stars with Winds. II. Line-Blanketed Models
• Formation of the First Stars by Accretion
• Yellow supergiants as supernova progenitors: an indication of strong mass loss for red supergiants?
• Evolution of blue supergiants and αCygni variables; Puzzling CNO surface abundances
• Periodic mass loss episodes due to an oscillation mode with variable amplitude in the hot supergiant HD50064
• Fully Nonadiabatic Analysis of Vibrational Instability of Population III Stars due to the $\epsilon$-Mechanism

Cited by in corpus (4)

• Pulsations of red supergiant pair-instability supernova progenitors leading to extreme mass loss
• Stellar oscillations. II The non-adiabatic case
• Pulsations of Pre-White Dwarfs with Hydrogen-dominated Atmospheres
• Instability, finite amplitude pulsation and mass-loss in models of massive OB-type stars