Theoretical studies of massive stars. II - Evolution of a 15 solar-mass star from carbon shell burning to iron core collapse

1980 ◽  
Vol 237 ◽  
pp. 130 ◽  
Author(s):  
W. M. Sparks ◽  
A. S. Endal
Keyword(s):  
Massive Stars ◽  
Carbon Shell ◽  
Iron Core ◽  
Core Collapse ◽  
Mass Star ◽  
Theoretical Studies ◽  
Solar Mass

scholarly journals The Status of Multi-Dimensional Core-Collapse Supernova Models

2016 ◽  
Vol 33 ◽  
Author(s):  
B. Müller
Keyword(s):  
Initial Conditions ◽  
Massive Stars ◽  
Core Collapse ◽  
Solar Mass ◽  
Convective Boundary ◽  
3D Simulations ◽  
Core Collapse Supernova ◽  
Wide Range ◽  
Supernova Explosions ◽  
The Impact

AbstractModels of neutrino-driven core-collapse supernova explosions have matured considerably in recent years. Explosions of low-mass progenitors can routinely be simulated in 1D, 2D, and 3D. Nucleosynthesis calculations indicate that these supernovae could be contributors of some lighter neutron-rich elements beyond iron. The explosion mechanism of more massive stars remains under investigation, although first 3D models of neutrino-driven explosions employing multi-group neutrino transport have become available. Together with earlier 2D models and more simplified 3D simulations, these have elucidated the interplay between neutrino heating and hydrodynamic instabilities in the post-shock region that is essential for shock revival. However, some physical ingredients may still need to be added/improved before simulations can robustly explain supernova explosions over a wide range of progenitors. Solutions recently suggested in the literature include uncertainties in the neutrino rates, rotation, and seed perturbations from convective shell burning. We review the implications of 3D simulations of shell burning in supernova progenitors for the ‘perturbations-aided neutrino-driven mechanism,’ whose efficacy is illustrated by the first successful multi-group neutrino hydrodynamics simulation of an 18 solar mass progenitor with 3D initial conditions. We conclude with speculations about the impact of 3D effects on the structure of massive stars through convective boundary mixing.

scholarly journals The Three-dimensional Collapse of a Rapidly Rotating 16 M ⊙ Star

2022 ◽  
Vol 924 (1) ◽  
pp. L15
Author(s):  
C. E. Fields
Keyword(s):  
Massive Stars ◽  
Gravitational Instability ◽  
Three Dimensional ◽  
Iron Core ◽  
Core Collapse ◽  
Hydrodynamic Evolution ◽  
Tightly Coupled ◽  
Critical Components ◽  
Rotating Shell ◽  
First Time

Abstract I report on the three-dimensional (3D) hydrodynamic evolution of a rapidly rotating 16 M ⊙ star to iron core collapse. For the first time, I follow the 3D evolution of the angular momentum (AM) distribution in the iron core and convective shell burning regions for the final 10 minutes up to and including gravitational instability and core collapse. In 3D, convective regions show efficient AM transport that leads to an AM profile that differs in shape and magnitude from MESA within a few shell convective turnover timescales. For different progenitor models, such as those with tightly coupled Si/O convective shells, efficient AM transport in 3D simulations could lead to a significantly different AM distribution in the stellar interior affecting estimates of the natal neutron star or black hole spin. The results suggest that 3D AM transport in convective and rotating shell burning regions are critical components in models of massive stars and could qualitatively alter the explosion outcome and inferred compact remnant properties.

S-process nucleosynthesis in massive stars and the weak component. I - Evolution and neutron captures in a 25 solar mass star

1991 ◽  
Vol 367 ◽  
pp. 228 ◽  
Author(s):  
C. M. Raiteri ◽  
M. Busso ◽  
G. Picchio ◽  
R. Gallino ◽  
L. Pulone
Keyword(s):  
Massive Stars ◽  
Mass Star ◽  
Solar Mass ◽  
Weak Component

scholarly journals The pre-supernova evolution of rotating massive stars

2003 ◽  
Vol 212 ◽  
pp. 357-364 ◽  
Author(s):  
Alexander Heger ◽  
Stan E. Woosley ◽  
Norbert Langer
Keyword(s):  
Angular Momentum ◽  
Magnetic Fields ◽  
Main Sequence ◽  
Massive Stars ◽  
Iron Core ◽  
Core Collapse ◽  
Mode Instability ◽  
Angular Momentum Transport ◽  
Explosion Mechanism ◽  
Chemical Mixing

Massive stars are born rotating rigidly with a significant fraction of critical rotation at the surface. Consequently, rotationally-induced circulation and instabilities lead to chemical mixing in regions that would otherwise be stable, as well as a redistribution of angular momentum. Differential rotation also winds up magnetic fields, causing instabilities that can power a dynamo and magnetic stresses that lead to additional angular momentum transport. We follow the evolution of typical massive stars, their structure and angular momentum distribution, from the zero-age main sequence until iron core collapse. Without the action of magnetic fields, the resulting angular momentum is sufficiently large to significantly affect the explosion mechanism and neutron star formation. Sub-millisecond pulsars result that could encounter the r-mode instability. In helium cores massive enough, at least at low metalicity, the angular momentum is also sufficiently great to form a centrifugally supported accretion disk around a central black hole, powering the engine of the ‘collapsar’ model for GRBs. Including current estimates of the effect of magnetic fields still allows the formation of rapidly rotating (~ 5-10 ms) pulsars, but might leave too little angular momentum for collapsars.

scholarly journals MRI-active inner regions of protoplanetary discs. I. A detailed model of disc structure

2021 ◽  
Vol 504 (1) ◽  
pp. 280-299
Author(s):  
Marija R Jankovic ◽  
James E Owen ◽  
Subhanjoy Mohanty ◽  
Jonathan C Tan
Keyword(s):  
Energy Transport ◽  
Threshold Temperature ◽  
Mass Star ◽  
Dust Grains ◽  
Solar Mass ◽  
Detailed Model ◽  
Short Period ◽  
Pressure Maximum ◽  
Ion Emission ◽  
Protoplanetary Discs

ABSTRACT Short-period super-Earth-sized planets are common. Explaining how they form near their present orbits requires understanding the structure of the inner regions of protoplanetary discs. Previous studies have argued that the hot inner protoplanetary disc is unstable to the magnetorotational instability (MRI) due to thermal ionization of potassium, and that a local gas pressure maximum forms at the outer edge of this MRI-active zone. Here we present a steady-state model for inner discs accreting viscously, primarily due to the MRI. The structure and MRI-viscosity of the inner disc are fully coupled in our model; moreover, we account for many processes omitted in previous such models, including disc heating by both accretion and stellar irradiation, vertical energy transport, realistic dust opacities, dust effects on disc ionization, and non-thermal sources of ionization. For a disc around a solar-mass star with a standard gas accretion rate ($\dot{M}\, \sim \, 10^{-8}$ M⊙ yr−1) and small dust grains, we find that the inner disc is optically thick, and the accretion heat is primarily released near the mid-plane. As a result, both the disc mid-plane temperature and the location of the pressure maximum are only marginally affected by stellar irradiation, and the inner disc is also convectively unstable. As previously suggested, the inner disc is primarily ionized through thermionic and potassium ion emission from dust grains, which, at high temperatures, counteract adsorption of free charges on to grains. Our results show that the location of the pressure maximum is determined by the threshold temperature above which thermionic and ion emission become efficient.

scholarly journals A shallow water analogue of asymmetric core-collapse, and neutron star kick/spin

2011 ◽  
Vol 7 (S279) ◽  
pp. 134-137
Author(s):  
Thierry Foglizzo ◽  
Frédéric Masset ◽  
Jérôme Guilet ◽  
Gilles Durand
Keyword(s):  
Neutron Star ◽  
Shallow Water ◽  
Acoustic Waves ◽  
Large Scale ◽  
Massive Stars ◽  
Core Collapse ◽  
Hydraulic Jumps ◽  
Core Collapse Supernova ◽  
Accretion Shock

AbstractMassive stars end their life with the gravitational collapse of their core and the formation of a neutron star. Their explosion as a supernova depends on the revival of a spherical accretion shock, located in the inner 200km and stalled during a few hundred milliseconds. Numerical simulations suggest that the large scale asymmetry of the neutrino-driven explosion is induced by a hydrodynamical instability named SASI. Its non radial character is able to influence the kick and the spin of the resulting neutron star. The SWASI experiment is a simple shallow water analog of SASI, where the role of acoustic waves and shocks is played by surface waves and hydraulic jumps. Distances in the experiment are scaled down by a factor one million, and time is slower by a factor one hundred. This experiment is designed to illustrate the asymmetric nature of core-collapse supernova.

scholarly journals Lithium, beryllium, and boron production in core-collapse supernovae

2009 ◽  
Vol 5 (S268) ◽  
pp. 463-468
Author(s):  
Ko Nakamura ◽  
Takashi Yoshida ◽  
Toshikazu Shigeyama ◽  
Toshitaka Kajino
Keyword(s):  
Massive Star ◽  
Massive Stars ◽  
Circumstellar Matter ◽  
High Energy ◽  
Core Collapse ◽  
Light Elements ◽  
Speed Of Light ◽  
Large Numbers ◽  
Very High Energy ◽  
Very High

AbstractType Ic supernova (SN Ic) is the gravitational collapse of a massive star without H and He layers. It propels several solar masses of material to the typical velocity of 10,000 km/s, a very small fraction of the ejecta nearly to the speed of light. We investigate SNe Ic as production sites for the light elements Li, Be, and B, via the neutrino-process and spallations. As massive stars collapse, neutrinos are emitted in large numbers from the central remnants. Some of the neutrinos interact with nuclei in the exploding materials and mainly 7Li and 11B are produced. Subsequently, the ejected materials with very high energy impinge on the interstellar/circumstellar matter and spall into light elements. We find that the ν-process in the current SN Ic model produces a significant amount of 11B, consistent with observations if combined with B isotopes from the following spallation production.

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