scholarly journals Stellar Yields of Rotating First Stars: Yields of Weak Supernovae and Abundances of Carbon-enhanced Hyper Metal Poor Stars

2014 ◽  
Vol 9 (S307) ◽  
pp. 82-87
Author(s):  
Koh Takahashi ◽  
Hideyuki Umeda ◽  
Takashi Yoshida
Keyword(s):  
Early Universe ◽  
Theoretical Study ◽  
Outer Region ◽  
Initial Parameter ◽  
Intermediate Mass ◽  
First Stars ◽  
Future Observation ◽  
Abundance Patterns ◽  
Iron Deficient ◽  
Rotational Property

AbstractThe three most iron-poor stars known until now are also known to have peculiar enhancements of intermediate mass elements. Under the assumption that these iron-deficient stars reveal the nucleosynthesis result of Pop III stars, we show that a weak supernova model successfully reproduces the observed abundance patterns. Moreover, we show that the initial parameters of the progenitor, such as the initial masses and the rotational property, can be constrained by the model, since the stellar yields result from the nucleosynthesis in the outer region of the star, which is significantly affected by the initial parameters. The initial parameter of Pop III stars is of prime importance for the theoretical study of the early universe. Future observation will increase the number of such carbon enhanced iron-deficient stars, and the same analysis on the stars may give valuable information for the Pop III stars that existed in our universe.

First stars, hypernovae, and superluminous supernovae

2016 ◽  
Vol 25 (10) ◽  
pp. 1630025
Author(s):  
Ken’ichi Nomoto
Keyword(s):  
Early Universe ◽  
Big Bang ◽  
Elemental Abundance ◽  
Heavy Elements ◽  
Relativistic Jets ◽  
First Stars ◽  
Evolution Of Galaxies ◽  
Abundance Patterns ◽  
The Big Bang

After the big bang, production of heavy elements in the early universe takes place starting from the formation of the first (Pop III) stars, their evolution, and explosion. The Pop III supernova (SN) explosions have strong dynamical, thermal, and chemical feedback on the formation of subsequent stars and evolution of galaxies. However, the nature of Pop III stars/supernovae (SNe) have not been well-understood. The signature of nucleosynthesis yields of the first SN can be seen in the elemental abundance patterns observed in extremely metal-poor (EMP) stars. We show that the abundance patterns of EMP stars, e.g. the excess of C, Co, Zn relative to Fe, are in better agreement with the yields of hyper-energetic explosions (Hypernovae, (HNe)) rather than normal supernovae. We note the large variation of the abundance patterns of EMP stars propose that such a variation is related to the diversity of the GRB-SNe and posssibly superluminous supernovae (SLSNe). For example, the carbon-enhanced metal-poor (CEMP) stars may be related to the faint SNe (or dark HNe), which could be the explosions induced by relativistic jets. Finally, we examine the various mechanisms of SLSNe.

scholarly journals Feeding and feedback from little monsters: AGN in dwarf galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 238-242
Author(s):  
Mar Mezcua
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Early Universe ◽  
Dwarf Galaxies ◽  
Scaling Relations ◽  
Strong Impact ◽  
Hole Formation ◽  
Intermediate Mass ◽  
Black Hole Formation ◽  
Low Mass

AbstractDetecting the seed black holes from which quasars formed is extremely challenging; however, those seeds that did not grow into supermassive should be found as intermediate-mass black holes (IMBHs) of 100 – 105 M⊙ in local dwarf galaxies. The use of deep multiwavelength surveys has revealed that a population of actively accreting IMBHs (low-mass AGN) exists in dwarf galaxies at least out to z ˜3. The black hole occupation fraction of these galaxies suggests that the early Universe seed black holes formed from direct collapse of gas, which is reinforced by the possible flattening of the black hole-galaxy scaling relations at the low-mass end. This scenario is however challenged by the finding that AGN feedback can have a strong impact on dwarf galaxies, which implies that low-mass AGN in dwarf galaxies might not be the untouched relics of the early seed black holes. This has important implications for seed black hole formation models.

scholarly journals An Explosive End to Intermediate‐Mass Zero‐Metallicity Stars and Early Universe Nucleosynthesis

2008 ◽  
Author(s):  
Herbert H.B. Lau ◽  
Richard J. Stancliffe ◽  
Christopher A. Tout
Keyword(s):  
Early Universe ◽  
Intermediate Mass

scholarly journals Core Collapse Supernova Models and Nucleosynthesis

2013 ◽  
Vol 9 (S296) ◽  
pp. 27-36
Author(s):  
Ken'ichi Nomoto
Keyword(s):  
Big Bang ◽  
Elemental Abundance ◽  
Core Collapse ◽  
Solar Abundance ◽  
First Stars ◽  
Abundance Pattern ◽  
Core Collapse Supernova ◽  
Abundance Patterns ◽  
Supernova Explosions ◽  
The Big Bang

AbstractAfter the Big Bang, production of heavy elements in the early Universe takes place in the first stars and their supernova explosions. The nature of the first supernovae, however, has not been well understood. The signature of nucleosynthesis yields of the first supernovae can be seen in the elemental abundance patterns observed in extremely metal-poor stars. Interestingly, those abundance patterns show some peculiarities relative to the solar abundance pattern, which should provide important clues to understanding the nature of early generations of supernovae. We review the recent results of the nucleosynthesis yields of massive stars. We examine how those yields are affected by some hydrodynamical effects during the supernova explosions, namely, explosion energies from those of hypernovae to faint supernovae, mixing and fallback of processed materials, asphericity, etc. Those parameters in the supernova nucleosynthesis models are constrained from observational data of supernovae and metal-poor stars.

scholarly journals An Explosive End to Intermediate-Mass Zero-Metallicity Stars and Early Universe Nucleosynthesis

2007 ◽  
Author(s):  
Herbert H. B. Lau ◽  
Richard J. Stancliffe ◽  
Christopher A. Tout ◽  
Richard J. Stancliffe ◽  
Guenter Houdek ◽  
...  
Keyword(s):  
Early Universe ◽  
Intermediate Mass

The First Stars

2013 ◽  
Author(s):  
Abraham Loeb ◽  
Steven R. Furlanetto
Keyword(s):  
Phase Transition ◽  
Early Universe ◽  
Galaxy Formation ◽  
Big Bang ◽  
First Stars ◽  
Complex Chemical ◽  
Radiative Processes ◽  
Complex Processes ◽  
The Big Bang ◽  
The Universe

This chapter considers the emergence of the complex chemical and radiative processes during the first stages of galaxy formation. It studies the appearance of the first stars, their feedback processes, and the resulting ionization structures that emerged during and shortly after the cosmic dawn. The formation of the first stars tens or hundreds of millions of years after the Big Bang had marked a crucial transition in the early Universe. Before this point, the Universe was elegantly described by a small number of parameters. But as soon as the first stars formed, more complex processes entered the scene. To illustrate this, the chapter provides a brief outline of the prevailing (though observationally untested) theory for this cosmological phase transition.

scholarly journals First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy

2004 ◽  
Vol 416 (3) ◽  
pp. 1117-1138 ◽  
Author(s):  
R. Cayrel ◽  
E. Depagne ◽  
M. Spite ◽  
V. Hill ◽  
F. Spite ◽  
...  
Keyword(s):  
First Stars ◽  
Abundance Patterns ◽  
Early Galaxy

scholarly journals The First Stars

2002 ◽  
Vol 187 ◽  
pp. 23-32
Author(s):  
David Arnett
Keyword(s):  
Early Universe ◽  
First Generation ◽  
Heavy Elements ◽  
First Stars ◽  
Neutron Excess ◽  
Explosive Burning

The possible nature of the first generation of stars is considered, using a star of 25M⊙ as an example. General nucleosynthesis and the production of CNO catalysts is examined in detail. The increase in neutron excess and its significance for yields from explosive burning is discussed. An estimate of the ratio of ionizing photons to heavy elements produced is derived, for use in early universe simulations.

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