On the Possibility of the Nonexplosive Core Contraction of Massive Stars. II. General Relativistic Analysis

1999 ◽  
Vol 521 (1) ◽  
pp. 376-381 ◽  
Author(s):  
Atsuyuki Hayashi ◽  
Yoshiharu Eriguchi ◽  
Masa‐aki Hashimoto
Keyword(s):  
Massive Stars ◽  
General Relativistic ◽  
Relativistic Analysis

scholarly journals On monolithic supermassive stars

2020 ◽  
Vol 494 (2) ◽  
pp. 2236-2243 ◽  
Author(s):  
Tyrone E Woods ◽  
Alexander Heger ◽  
Lionel Haemmerlé
Keyword(s):  
Early Universe ◽  
Stellar Evolution ◽  
Time Scale ◽  
Main Sequence ◽  
Massive Stars ◽  
Rotating Stars ◽  
One Dimensional ◽  
General Relativistic ◽  
The One ◽  
Limiting Case

ABSTRACT Supermassive stars have been proposed as the progenitors of the massive ($\sim \!10^{9}\, \mathrm{M}_{\odot }$) quasars observed at z ∼ 7. Prospects for directly detecting supermassive stars with next-generation facilities depend critically on their intrinsic lifetimes, as well as their formation rates. We use the one-dimensional stellar evolution code kepler to explore the theoretical limiting case of zero-metallicity non-rotating stars, formed monolithically with initial masses between $10$ and $190\, \mathrm{kM}_{\odot }$. We find that stars born with masses between $\sim\! 60$ and $\sim\! 150\, \mathrm{kM}_{\odot }$ collapse at the end of the main sequence, burning stably for $\sim\! 1.5\, \mathrm{Myr}$. More massive stars collapse directly through the general relativistic instability after only a thermal time-scale of $\sim\! 3$–$4\, \mathrm{kyr}$. The expected difficulty in producing such massive thermally relaxed objects, together with recent results for currently preferred rapidly accreting formation models, suggests that such ‘truly direct’ or ‘dark’ collapses may not be typical for supermassive objects in the early Universe. We close by discussing the evolution of supermassive stars in the broader context of massive primordial stellar evolution and the possibility of supermassive stellar explosions.

scholarly journals General relativistic analysis of peculiar velocities

2001 ◽  
Vol 18 (23) ◽  
pp. 5115-5123 ◽  
Author(s):  
George F R Ellis ◽  
Henk van Elst ◽  
Roy Maartens
Keyword(s):  
Peculiar Velocities ◽  
General Relativistic ◽  
Relativistic Analysis

Finite-amplitude Adiabatic Oscillations of Super-massive Stars

1968 ◽  
Vol 1 (3) ◽  
pp. 87-88
Author(s):  
R. Van Der Borght
Keyword(s):  
Differential Equation ◽  
Fundamental Mode ◽  
Main Sequence ◽  
Massive Stars ◽  
Relativistic Correction ◽  
Finite Amplitude ◽  
Hydrogen Burning ◽  
Upper Limit ◽  
Considerable Simplification ◽  
General Relativistic

As shown recently by Y. Osaki super-massive stars with mass M < 3.5 × 105M⊙ can, in the absence of rotation, reach the hydrogen-burning main sequence before the onset of general relativistic instability. Such objects are then pulsationally unstable. A considerable simplification is introduced if one considers only very massive stars, for which the relative amplitude of the fundamental mode of oscillation is practically constant. This sets a lower limit of 104M⊙ to the mass that can be considered. The upper limit is also reduced to 2 × 105M⊙ if one neglects the relativistic correction. One necessary step in the study of non-linear oscillations of massive stars is to derive a differential equation for the adiabatic pulsations. The relativistic correction could be taken into account in the following way.

scholarly journals GAMMA-RAY BURSTS AS THE BIRTH-CRIES OF BLACK HOLES

2000 ◽  
Vol 15 (15) ◽  
pp. 991-995 ◽  
Author(s):  
PANKAJ S. JOSHI ◽  
NARESH K. DADHICH ◽  
ROY MAARTENS
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gamma Ray ◽  
Massive Stars ◽  
Relativistic Effects ◽  
Gamma Ray Bursts ◽  
Trapped Surfaces ◽  
General Relativistic

The origin of cosmic gamma-ray bursts remains one of the most intriguing puzzles in astronomy. We suggest that purely general relativistic effects in the collapse of massive stars could account for these bursts. The late formation of closed trapped surfaces can occur naturally, allowing the escape of huge energy from curvature-generated fireballs, before these are hidden within a black hole.

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