scholarly journals Nucleosynthesis of the Elements in Faint Supernovae and Hypernovae

2009 ◽  
Vol 5 (S265) ◽  
pp. 34-41
Author(s):  
Ken'ichi Nomoto ◽  
Takashi Moriya ◽  
Nozomu Tominaga
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Electron Capture ◽  
Massive Stars ◽  
Core Collapse ◽  
Agb Stars ◽  
Intermediate Mass ◽  
Normal Core ◽  
Intermediate Mass Black Holes

AbstractWe review the properties of supernovae (SNe) as a function of the progenitor's mass M. (1) Mup - 10 M⊙ stars are super-AGB stars and resultant electron capture SNe may be Faint supernovae like Type IIn SN 2008S. (2) 10 - 12 M⊙ stars undergo Fe-core collapse to form neutron stars (NSs) and Faint supernovae. (3) 12 M⊙ - MBN stars undergo Fe-core collapse to form NSs and normal core-collapse supernovae. (4) MBN - 90 M⊙ stars undergo Fe-core collapse to form Black Holes. Resultant supernovae are bifurcate into Hypernovae and Faint supernovae. The observed properties of SN 2008ha can be explained with this type of Faint supernovae. (5) 90 - 140 M⊙ stars produce Luminous SNe, like SNe 2007bi and 2006gy. (6) 140 - 300 M⊙ stars become pair-instability supernovae which could be Luminous supernovae (SNe 2007bi and 2006gy). (7) Very massive stars with M ≳ 300 M⊙ undergo core-collapse to form intermediate mass black holes. Some SNe could be more Luminous supernovae (like SN 2006gy).

scholarly journals Chemical Yields from Supernovae and Hypernovae

2008 ◽  
Vol 4 (S254) ◽  
pp. 355-368 ◽  
Author(s):  
Ken'ichi Nomoto ◽  
Shinya Wanajo ◽  
Yasuomi Kamiya ◽  
Nozomu Tominaga ◽  
Hideyuki Umeda
Keyword(s):  
Black Holes ◽  
Mass Loss ◽  
Electron Capture ◽  
Stellar Evolution ◽  
Massive Stars ◽  
Core Collapse ◽  
Agb Stars ◽  
Intermediate Mass ◽  
Abundance Patterns ◽  
Nuclear Burning

AbstractWe review the final stages of stellar evolution, supernova properties, and chemical yields as a function of the progenitor's mass. (1) 8 - 10 M⊙ stars are super-AGB stars when the O+Ne+Mg core collapses due to electron capture. These AGB-supernovae may constitute an SN 2008S-like sub-class of Type IIn supernovae. These stars produce little α-elements and Fe-peak elements, but are important sources of Zn and light p-nuclei. (2) 10 - 90 M⊙ stars undergo Fe-core collapse. Nucleosynthesis in aspherical explosions is important, as it can well reproduce the abundance patterns observed in extremely metal-poor stars. (3) 90 - 140 M⊙ stars undergo pulsational nuclear instabilities at various nuclear burning stages, including O and Si-burning. (4) Very massive stars with M ≳ 140 M⊙ either become pair-instability SNe, or undergo core-collapse to form intermediate mass black holes if the mass loss is small enough.

scholarly journals Explosion of very massive stars and the origin of intermediate mass black holes

2006 ◽  
Vol 2 (S238) ◽  
pp. 241-246
Author(s):  
Sachiko Tsuruta ◽  
Takuya Ohkubo ◽  
Hideyuki Umeda ◽  
Keiichi Maeda ◽  
Ken'ichi Nomoto ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Massive Stars ◽  
Core Collapse ◽  
Clusters Of Galaxies ◽  
Intermediate Mass ◽  
Black Hole Masses ◽  
Better Than ◽  
Intermediate Mass Black Holes ◽  
Population Iii

AbstractWe calculate evolution, collapse, explosion, and nucleosynthesis of Population III very massive stars with 500 M⊙ and 1000 M⊙. It was found that both 500 M⊙ and 1000 M⊙ models enter the region of pair-instability but continue to undergo core collapse to black holes. For moderately aspherical explosions, the patterns of nucleosynthesis match the observational data of intergalactic and intercluster medium and hot gases in M82, better than models involving hypernovae and pair instability supernovae.Our results suggest that explosions of Population III core-collapse very massive stars contribute significantly to the chemical evolution of gases in clusters of galaxies. The final black hole masses are about 500 M⊙ for our most massive 1000 M⊙ models. This result may support the view that Population III very massive stars are responsible for the origin of intermediate mass black holes which were recently reported to be discovered.

scholarly journals Collisions in primordial star clusters

2018 ◽  
Vol 614 ◽  
pp. A14 ◽  
Author(s):  
B. Reinoso ◽  
D. R. G. Schleicher ◽  
M. Fellhauer ◽  
R. S. Klessen ◽  
T. C. N. Boekholt
Keyword(s):  
Black Holes ◽  
Massive Stars ◽  
Star Clusters ◽  
Parameter Study ◽  
Effective Parameters ◽  
Intermediate Mass ◽  
Stellar Collisions ◽  
Accretion Rates ◽  
Relevant Role ◽  
Intermediate Mass Black Holes

Collisions were suggested to potentially play a role in the formation of massive stars in present day clusters, and have likely been relevant during the formation of massive stars and intermediate mass black holes within the first star clusters. In the early Universe, the first stellar clusters were particularly dense, as fragmentation typically only occurred at densities above 109 cm−3, and the radii of the protostars were enhanced as a result of larger accretion rates, suggesting a potentially more relevant role of stellar collisions. We present here a detailed parameter study to assess how the number of collisions and the mass growth of the most massive object depend on the properties of the cluster. We also characterize the time evolution with three effective parameters: the time when most collisions occur, the duration of the collisions period, and the normalization required to obtain the total number of collisions. We apply our results to typical Population III (Pop. III) clusters of about 1000 M⊙, finding that a moderate enhancement of the mass of the most massive star by a factor of a few can be expected. For more massive Pop. III clusters as expected in the first atomic cooling halos, we expect a more significant enhancement by a factor of 15–32. We therefore conclude that collisions in massive Pop. III clusters were likely relevant to form the first intermediate mass black holes.

scholarly journals The Formation of Very Massive Stars in Early Galaxies and Implications for Intermediate Mass Black Holes

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
John A. Regan ◽  
John H. Wise ◽  
Tyrone E. Woods ◽  
Turlough P. Downes ◽  
Brian W. O'Shea ◽  
...  
Keyword(s):  
Black Holes ◽  
Massive Stars ◽  
Intermediate Mass ◽  
Early Galaxies ◽  
Intermediate Mass Black Holes

scholarly journals INTERMEDIATE-MASS BLACK HOLES

2004 ◽  
Vol 13 (01) ◽  
pp. 1-64 ◽  
Author(s):  
M. COLEMAN MILLER ◽  
E. J. M. COLBERT
Keyword(s):  
Black Holes ◽  
Theoretical Work ◽  
Core Collapse ◽  
Stellar Clusters ◽  
Intermediate Mass ◽  
Fundamental Physics ◽  
The Core ◽  
M 10 ◽  
The Universe ◽  
Intermediate Mass Black Holes

The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (M~3–20 M⊙), which are produced by the core collapse of massive stars, and supermassive (M~106–1010 M⊙), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with M~102–104 M⊙. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work that will help clarify numerous outstanding questions about these objects.

scholarly journals Progenitors of electron-capture supernovae

2011 ◽  
Vol 7 (S279) ◽  
pp. 341-342
Author(s):  
Samuel Jones ◽  
Raphael Hirschi ◽  
Falk Herwig ◽  
Bill Paxton ◽  
Francis X. Timmes ◽  
...  
Keyword(s):  
Electron Capture ◽  
Massive Star ◽  
Massive Stars ◽  
Large Fraction ◽  
Mass Range ◽  
Light Curves ◽  
Core Collapse ◽  
Type Ii ◽  
Agb Stars ◽  
Lower Edge

AbstractWe investigate the lowest mass stars that produce Type-II supernovae, motivated by recent results showing that a large fraction of type-II supernova progenitors for which there are direct detections display unexpectedly low luminosity (for a review see e.g. Smartt 2009). There are three potential evolutionary channels leading to this fate. Alongside the standard ‘massive star’ Fe-core collapse scenario we investigate the likelihood of electron capture supernovae (EC-SNe) from super-AGB (S-AGB) stars in their thermal pulse phase, from failed massive stars for which neon burning and other advanced burning stages fail to prevent the star from contracting to the critical densities required to initiate rapid electron-capture reactions and thus the star's collapse. We find it indeed possible that both of these relatively exotic evolutionary channels may be realised but it is currently unclear for what proportion of stars. Ultimately, the supernova light curves, explosion energies, remnant properties (see e.g. Knigge et al. 2011) and ejecta composition are the quantities desired to establish the role that these stars at the lower edge of the massive star mass range play.

scholarly journals Intermediate mass black holes in AGN discs - I. Production and growth

2012 ◽  
Vol 425 (1) ◽  
pp. 460-469 ◽  
Author(s):  
B. McKernan ◽  
K. E. S. Ford ◽  
W. Lyra ◽  
H. B. Perets
Keyword(s):  
Black Holes ◽  
Intermediate Mass ◽  
Intermediate Mass Black Holes
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