scholarly journals Mass loss and evolution of hot massive stars

2008 ◽  
Vol 4 (S252) ◽  
pp. 271-281 ◽  
Author(s):  
Jorick S. Vink
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Main Sequence ◽  
Gamma Ray ◽  
Massive Stars ◽  
Gamma Ray Bursts ◽  
Absorption Profile ◽  
Luminous Blue Variables ◽  
Progenitor Stars

AbstractWe discuss the role of mass loss for the evolution of the most massive stars, highlighting the role of the predicted bi-stability jump that might be relevant for the evolution of rotational velocities during or just after the main sequence. This mechanism is also proposed as an explanation for the mass-loss variations seen in the winds from Luminous Blue Variables (LBVs). These might be relevant for the quasi-sinusoidal modulations seen in a number of recent transitional supernovae (SNe), as well as for the double-throughed absorption profile recently discovered in the Hα line of SN 2005gj. Finally, we discuss the role of metallicity via the Z-dependent character of their winds, during both the initial and final (Wolf-Rayet) phases of evolution, with implications for the angular momentum evolution of the progenitor stars of long gamma-ray bursts (GRBs).

scholarly journals Evolution of rotation in rapidly rotating early-type stars during the main sequence with 2D models

2019 ◽  
Vol 625 ◽  
pp. A89 ◽  
Author(s):  
D. Gagnier ◽  
M. Rieutord ◽  
C. Charbonnel ◽  
B. Putigny ◽  
F. Espinosa Lara
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Main Sequence ◽  
Massive Stars ◽  
Early Type ◽  
Wind Regime ◽  
Momentum Loss ◽  
Angular Momentum Loss ◽  
Rotational Evolution ◽  
Early Type Stars

The understanding of the rotational evolution of early-type stars is deeply related to that of anisotropic mass and angular momentum loss. In this paper, we aim to clarify the rotational evolution of rapidly rotating early-type stars along the main sequence (MS). We have used the 2D ESTER code to compute and evolve isolated rapidly rotating early-type stellar models along the MS, with and without anisotropic mass loss. We show that stars with Z = 0.02 and masses between 5 and 7 M⊙ reach criticality during the main sequence provided their initial angular velocity is larger than 50% of the Keplerian one. More massive stars are subject to radiation-driven winds and to an associated loss of mass and angular momentum. We find that this angular momentum extraction from the outer layers can prevent massive stars from reaching critical rotation and greatly reduce the degree of criticality at the end of the MS. Our model includes the so-called bi-stability jump of the Ṁ − Teff relation of 1D-models. This discontinuity now shows up in the latitude variations of the mass-flux surface density, endowing rotating massive stars with either a single-wind regime (no discontinuity) or a two-wind regime (a discontinuity). In the two-wind regime, mass loss and angular momentum loss are strongly increased at low latitudes inducing a faster slow-down of the rotation. However, predicting the rotational fate of a massive star is difficult, mainly because of the non-linearity of the phenomena involved and their strong dependence on uncertain prescriptions. Moreover, the very existence of the bi-stability jump in mass-loss rate remains to be substantiated by observations.

scholarly journals Mass loss and the Eddington parameter: a new mass-loss recipe for hot and massive stars

2020 ◽  
Vol 493 (3) ◽  
pp. 3938-3946 ◽  
Author(s):  
Joachim M Bestenlehner
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Main Sequence ◽  
Gamma Ray ◽  
Massive Stars ◽  
Dominant Role ◽  
Mass Loss Rate ◽  
Large Magellanic Cloud ◽  
Wind Regime ◽  
Wind Theory

ABSTRACT Mass loss through stellar winds plays a dominant role in the evolution of massive stars. In particular, the mass-loss rates of very massive stars ($\gt 100\, M_{\odot}$) are highly uncertain. Such stars display Wolf–Rayet spectral morphologies (WNh), whilst on the main sequence. Metal-poor very massive stars are progenitors of gamma-ray bursts and pair instability supernovae. In this study, we extended the widely used stellar wind theory by Castor, Abbott & Klein from the optically thin (O star) to the optically thick main-sequence (WNh) wind regime. In particular, we modify the mass-loss rate formula in a way that we are able to explain the empirical mass-loss dependence on the Eddington parameter (Γe). The new mass-loss recipe is suitable for incorporation into current stellar evolution models for massive and very massive stars. It makes verifiable predictions, namely how the mass-loss rate scales with metallicity and at which Eddington parameter the transition from optically thin O star to optically thick WNh star winds occurs. In the case of the star cluster R136 in the Large Magellanic Cloud we find in the optically thin wind regime $\dot{M} \propto \Gamma _{\rm e}^{3}$, while in the optically thick wind regime $\dot{M} \propto 1/ (1 - \Gamma _{\rm e})^{3.5}$. The transition from optically thin to optically thick winds occurs at Γe, trans ≈ 0.47. The transition mass-loss rate is $\log \dot{M}~(\mathrm{M}_{\odot } \, \mathrm{yr}^{-1}) \approx -4.76 \pm 0.18$, which is in line with the prediction by Vink & Gräfener assuming a volume filling factor of $f_{\rm V} = 0.23_{-0.15}^{+0.40}$.

scholarly journals DIVISION IV / WORKING GROUP MASSIVE STARS

2008 ◽  
Vol 4 (T27A) ◽  
pp. 236-239
Author(s):  
Stanley P. Owocki ◽  
Paul A. Crowther ◽  
Alexander W. Fullerton ◽  
Gloria Koenigsberger ◽  
Norbert Langer ◽  
...  
Keyword(s):  
Working Group ◽  
Gamma Ray ◽  
Massive Stars ◽  
Gamma Ray Bursts ◽  
Core Collapse ◽  
Hot Stars ◽  
First Stars ◽  
Ob Stars ◽  
Red Supergiants

Our Working Group studies massive, luminous stars, with historical focus on early-type (OB) stars, but extending in recent years to include massive red supergiants that evolve from hot stars. There is also emphasis on the role of massive stars in other branches of astrophysics, particularly regarding starburst galaxies, the first stars, core-collapse gamma-ray bursts, and formation of massive stars.

scholarly journals Emission line spectropolarimetry and circumstellar structures

2014 ◽  
Vol 10 (S305) ◽  
pp. 288-292
Author(s):  
Jorick S. Vink
Keyword(s):  
Emission Line ◽  
Accretion Disks ◽  
Main Sequence ◽  
Gamma Ray ◽  
Young Stars ◽  
Main Sequence Stars ◽  
Current Sensitivity ◽  
Luminous Blue Variables ◽  
3D Monte Carlo

AbstractWe discuss the role of linear emission-line polarimetry in a wide set of stellar environments, involving the accretion disks around young pre-main sequence stars, to the aspherical outflows from O stars, luminous blue variables and Wolf-Rayet stars, just prior to explosion as a supernova or a gamma-ray burst. We predict subtle QU line signatures, such as single/double QU loops for un/disrupted disks. Whilst there is plenty of evidence for single QU loops, suggesting the presence of disrupted disks around young stars, current sensitivity (with S/N of order 1000) is typically not sufficient to allow for quantitative 3D Monte Carlo modeling. However, the detection of our predicted signatures is expected to become feasible with the massive improvement in sensitivity of extremely large mirrors.

scholarly journals DUST IN THE WIND: THE ROLE OF RECENT MASS LOSS IN LONG GAMMA-RAY BURSTS

2015 ◽  
Vol 805 (2) ◽  
pp. 159 ◽  
Author(s):  
R. Margutti ◽  
C. Guidorzi ◽  
D. Lazzati ◽  
D. Milisavljevic ◽  
A. Kamble ◽  
...  
Keyword(s):  
Mass Loss ◽  
Gamma Ray ◽  
Gamma Ray Bursts

scholarly journals Supernovae, Gamma-Ray Bursts and Stellar Rotation

2004 ◽  
Vol 215 ◽  
pp. 601-612 ◽  
Author(s):  
S. E. Woosley ◽  
A. Heger
Keyword(s):  
Angular Momentum ◽  
Neutron Star ◽  
Gamma Ray ◽  
Massive Stars ◽  
Supernova Explosion ◽  
Gamma Ray Bursts ◽  
Iron Core ◽  
Stellar Rotation ◽  
Explosion Mechanism ◽  
Stellar Mergers

One of the most dramatic possible consequences of stellar rotation is its influence on stellar death, particularly of massive stars. If the angular momentum of the iron core when it collapses is such as to produce a neutron star with a period of 5 ms or less, rotation will have important consequences for the supernova explosion mechanism. Still shorter periods, corresponding to a neutron star rotating at break up, are required for the progenitors of gamma-ray bursts (GRBs). Current stellar models, while providing an excess of angular momentum to pulsars, still fall short of what is needed to make GRBs. The possibility of slowing young neutron stars in ordinary supernovae by a combination of neutrino-powered winds and the propeller mechanism is discussed. The fall back of slowly moving ejecta during the first day of the supernova may be critical. GRBs, on the other hand, probably require stellar mergers for their production and perhaps less efficient mass loss and magnetic torques than estimated thus far.

scholarly journals Evolution of Progenitor Stars of Type Ibc Supernovae and Long Gamma-Ray Bursts

2007 ◽  
Vol 3 (S250) ◽  
pp. 231-236
Author(s):  
Sung-Chul Yoon ◽  
Norbert Langer ◽  
Matteo Cantiello ◽  
Stan E. Woosley ◽  
Gary A. Glatzmaier
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Massive Star ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Evolutionary Models ◽  
Single Star ◽  
Solar Metallicity ◽  
Progenitor Stars

AbstractWe discuss how rotation and binary interactions may be related to the diversity of type Ibc supernovae and long gamma-ray bursts. After presenting recent evolutionary models of massive single and binary stars including rotation, the Tayler-Spruit dynamo and binary interactions, we argue that the nature of SNe Ibc progenitors from binary systems may not significantly differ from that of single star progenitors in terms of rotation, and that most long GRB progenitors may be produced via the quasi-chemically homogeneous evolution at sub-solar metallicity. We also briefly discuss the possible role of magnetic fields generated in the convective core of a massive star for the transport of angular momentum, which is potentially important for future stellar evolution models of supernova and GRB progenitors.

scholarly journals Centrifugally driven mass-loss and outbursts of massive stars

2020 ◽  
Vol 495 (1) ◽  
pp. 249-265 ◽  
Author(s):  
Xihui Zhao ◽  
Jim Fuller
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Stellar Evolution ◽  
Main Sequence ◽  
Massive Stars ◽  
Variable Stars ◽  
Be Stars ◽  
Rotational Evolution ◽  
Break Up ◽  
Ultimate Fate

ABSTRACT Rotation and mass-loss are crucially interlinked properties of massive stars, strongly affecting their evolution and ultimate fate. Massive stars rotating near their break-up limit shed mass centrifugally, creating Be stars with circumstellar discs and possibly driving outbursts. Using the mesa stellar evolution code, we examine the effects of efficient angular momentum transport on the main-sequence and post-main-sequence rotational evolution of massive stars. In rapid rotators, angular momentum transported from the contracting core to the expanding envelope can spin-up the surface layers past the break-up rate, particularly for stars near (or beyond) the end of the main-sequence and in low-metallicity environments. We also demonstrate that centrifugal instabilities could arise in rapidly rotating massive stars, potentially triggering the S Doradus outbursts observed in luminous blue variable stars. Prior mass accretion from a binary companion increases both the likelihood and the intensity of centrifugal mass-loss. We discuss implications for massive stellar evolution, Be stars, and luminous blue variables.

scholarly journals Wind anisotropy and stellar evolution

2008 ◽  
Vol 4 (S255) ◽  
pp. 199-203
Author(s):  
Cyril Georgy ◽  
Georges Meynet ◽  
André Maeder
Keyword(s):  
Angular Momentum ◽  
Massive Star ◽  
Gamma Ray ◽  
Massive Stars ◽  
Gamma Ray Bursts ◽  
Surface Velocity ◽  
Hot Stars ◽  
Low Metallicity ◽  
Determinant Factor ◽  
Fast Rotating

AbstractMass loss is a determinant factor which strongly affects the evolution and the fate of massive stars. At low metallicity, stars are supposed to rotate faster than at the solar one. This favors the existence of stars near the critical velocity. In this rotation regime, the deformation of the stellar surface becomes important, and wind anisotropy develops. Polar winds are expected to be dominant for fast rotating hot stars.These polar winds allow the star to lose large quantities of mass and still retain a high angular momentum, and they modify the evolution of the surface velocity and the final angular momentum retained in the star's core. We show here how these winds affect the final stages of massive stars, according to our knowledge about Gamma Ray Bursts. Computation of theoretical Gamma Ray Bursts rate indicates that our models have too fast rotating cores, and that we need to include an additional effect to spin them down. Magnetic fields in stars act in this direction, and we show how they modify the evolution of massive star up to the final stages.

scholarly journals Presupernova Evolution of Rotating Massive Stars and the Rotation Rate of Pulsars

2004 ◽  
Vol 215 ◽  
pp. 591-600 ◽  
Author(s):  
A. Heger ◽  
S. E. Woosley ◽  
N. Langer ◽  
H. C. Spruit
Keyword(s):  
Angular Momentum ◽  
Neutron Stars ◽  
Rotation Rate ◽  
Main Sequence ◽  
Gamma Ray ◽  
Massive Stars ◽  
Hydrodynamic Instabilities ◽  
Order Of Magnitude ◽  
Advanced Stages ◽  
Explosion Mechanism

Rotation in massive stars has been studied on the main sequence and during helium burning for decades, but only recently have realistic numerical simulations followed the transport of angular momentum that occurs during more advanced stages of evolution. The results affect such interesting issues as whether rotation is important to the explosion mechanism, whether supernovae are strong sources of gravitational radiation, the star's nucleosynthesis, and the initial rotation rate of neutron stars and black holes. We find that when only hydrodynamic instabilities (shear, Eddington-Sweet, etc.) are included in the calculation, one obtains neutron stars spinning at close to critical rotation at their surface – or even formally in excess of critical. When recent estimates of magnetic torques (Spruit 2002) are added, however, the evolved cores spin about an order of magnitude slower. This is still more angular momentum than observed in young pulsars, but too slow for the collapsar model for gamma-ray bursts.

Sign in / Sign up

Export Citation Format

Share Document