搜索结果: 1-15 共查到“天文学 Nucleosynthesis”相关记录16条 . 查询时间(0.078 秒)
R-Process Nucleosynthesis in Dynamically Ejected Matter of Neutron Star Mergers
Nucleosynthesis Dynamically Ejected Matter Neutron Star Mergers
2011/9/28
Although the rapid neutron-capture process, or r-process, is fundamentally important for explaining the origin of approximately half of the stable nuclei with A > 60, the astrophysical site of this pr...
Products from massive-star nucleosynthesis have been measured with SPI on INTEGRAL: Characteristic gamma-ray lines from radioactive decays of long-lived 26Al and 60Fe isotopes, and from 44Ti decay (de...
Nucleosynthesis during the Merger of White Dwarfs and the Origin of R Coronae Borealis Stars
Dwarfs Origin Borealis Stars
2011/10/8
Many hydrogen deficient stars are characterised by surface abundance patterns that are hard to reconcile with conventional stellar evolution. Instead, it has been suggested that they may represent the...
56Ni, Explosive Nucleosynthesis, and SNe Ia Diversity
Explosive Nucleosynthesis SNe Ia Diversity
2011/9/29
The origin of the iron-group elements titanium to zinc in nature is understood to occur under explosive burning conditions in both Type Ia (thermonuclear) and Type II (core collapse) supernovae. In th...
Standard Big-Bang Nucleosynthesis up to CNO with an improved extended nuclear network
Big-Bang Nucleosynthesis improved extended nuclear network
2011/9/28
Primordial or Big Bang nucleosynthesis (BBN) is one of the three strong evidences for the Big- Bang model together with the expansion of the Universe and the Cosmic Microwave Background radiation. In ...
Nucleosynthesis origin of PG 1159 stars, Sakurai's object and of rare subclasses of presolar grains
Nucleosynthesis subclasses presolar grains
2011/9/27
We discuss theoretical AGB predictions for hydrogen-deficient PG 1159 stars and Sakurai's object, which show peculiar enhancements in He, C and O, and how these enhancements may be understood in the f...
The Stellar Abundances for Galactic Archaeology (SAGA) Database II - Implications for Mixing and Nucleosynthesis in Extremely Metal-Poor Stars and Chemical Enrichment of the Galaxy
The Stellar Abundances for Galactic Archaeology Database II
2011/1/13
We discuss the characteristics of known extremely metal-poor (EMP) stars in the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA) database (Suda et al. 2008, PASJ, 60, 1159).The anal...
Dark Radiation Emerging After Big Bang Nucleosynthesis?
Cosmology BBN CMB Equation of state
2010/11/16
We show how recent data from observations of the cosmic microwave back-ground may suggest the presence of additional radiation density which appeared after big bang nucleosynthesis. We propose a gener...
A refined constrain on lepton number from Big Bang Nucleosynthesis
Neutrinos physics of the early universe primordial asymmetries
2010/11/10
We study the evolution of primordial neutrino{antineutrino asymmetries in the early universe, before and during Big Bang Nucleosynthesis (BBN). We consider quite a wide range for the total lepton numb...
Abundance Patterns in S-type AGB stars : Setting Constraints on Nucleosynthesis and Stellar Evolution Models
Abundance Patterns Setting Constraints Stellar Evolution Models
2010/11/12
During the evolution on the AGB, S-type stars are the first objects to experience s-process nucleosynthesis and third dredge-ups, and therefore to exhibit sprocess signatures in their atmospheres.
A Carbon-enhanced Metal-poor Damped Lyman alpha System: Probing Gas from Population III Nucleosynthesis?
galaxies abundances − galaxies evolution − quasars absorption lines quasars: individual J0035− 0918 − stars carbon − stars
2010/11/10
We present high resolution observations of an extremely metal-poor damped Ly system, at zabs = 2.3400972 in the spectrum of the QSO J0035−0918, exhibiting an abundance pattern consistent with mo...
Big Bang Nucleosynthesis as a Probe of New Physics
Big bang nucleosynthesis early Universe abundances of light elements ex-tensions of the Standard Model dark matter
2010/11/16
Big bang nucleosynthesis (BBN), an epoch of primordial nuclear transforma-tions in the expanding Universe, has left an observable imprint in the abundances of light elements. Precision observations of...
Evolution and nucleosynthesis of extremely metal-poor and metal-free low- and intermediate-mass stars II. s-process nucleosynthesis during the core He flash
Solar and Stellar Astrophysics (astro-ph.SR)
2010/12/28
Models of primordial and hyper-metal-poor stars with masses similar to the Sun experience an ingestion of protons into the hot core during the core helium flash phase at the end of their red giant bra...
Electron screening and its effects on Big-Bang nucleosynthesis
Cosmology and Extragalactic Astrophysics (astro-ph.CO) High Energy Physics - Phenomenology (hep-ph) Nuclear Theory (nucl-th)
2010/12/27
We study the effects of electron screening on nuclear reaction rates occurring during the Big Bang nucleosynthesis epoch. The sensitivity of the predicted elemental abundances on electron screening is...
Using Big Bang Nucleosynthesis to Extend CMB Probes of Neutrino Physics
neutrino masses from cosmology big bang nucleosynthesis cosmological parameters from CMBR
2010/3/22
We present calculations showing that upcoming Cosmic Microwave Background (CMB) experiments will have the power to improve on current constraints on neutrino masses and provide new limits on neutrino ...