A low initial abundance of 247Cm in the early solar system and implications for r-process nucleosynthesis

2006 ◽  
Vol 251 (3-4) ◽  
pp. 386-397 ◽  
Author(s):  
C STIRLING ◽  
A HALLIDAY ◽  
E POTTER ◽  
M ANDERSEN ◽  
B ZANDA
Keyword(s):  
Solar System ◽  
Early Solar System ◽  
R Process

scholarly journals Turbulent mixing of r-process elements in the Milky Way

2020 ◽  
Vol 496 (2) ◽  
pp. 1891-1901 ◽  
Author(s):  
Paz Beniamini ◽  
Kenta Hotokezaka
Keyword(s):  
Solar System ◽  
Milky Way ◽  
Gas Diffusion ◽  
Star Formation History ◽  
Model Parameters ◽  
Early Solar System ◽  
Element Abundances ◽  
Process Event ◽  
R Process ◽  
Process Elements

ABSTRACT We study turbulent gas diffusion affects on r-process abundances in Milky Way stars, by a combination of an analytical approach and a Monte Carlo simulation. Higher r-process event rates and faster diffusion, lead to more efficient mixing corresponding to a reduced scatter of r-process abundances and causing r-process enriched stars to start appearing at lower metallicities. We use three independent observations to constrain the model parameters: (i) the scatter of radioactively stable r-process element abundances, (ii) the largest r-process enrichment values observed in any solar neighborhood stars, and (iii) the isotope abundance ratios of different radioactive r-process elements (244Pu/238U and 247Cm/238U) at the early Solar system as compared to their formation. Our results indicate that the Galactic r-process rate and the diffusion coefficient are respectively r < 4 × 10−5 yr−1, D > 0.1 kpc2 Gyr−1 (r < 4 × 10−6 yr−1, D > 0.5 kpc2 Gyr−1 for collapsars or similarly prolific r-process sources) with allowed values satisfying an approximate anticorrelation such that D ≈ r−2/3, implying that the time between two r-process events that enrich the same location in the Galaxy, is τmix ≈ 100−200 Myr. This suggests that a fraction of ∼0.8 (∼0.5) of the observed 247Cm (244Pu) abundance is dominated by one r-process event in the early Solar system. Radioactively stable element abundances are dominated by contributions from ∼10 different events in the early Solar system. For metal poor stars (with [Fe/H] ≲ −2), their r-process abundances are dominated by either a single or several events, depending on the star formation history.

scholarly journals 129I and 247Cm in meteorites constrain the last astrophysical source of solar r-process elements

Science ◽  
2021 ◽  
Vol 371 (6532) ◽  
pp. 945-948 ◽  
Author(s):  
Benoit Côté ◽  
Marius Eichler ◽  
Andrés Yagüe López ◽  
Nicole Vassh ◽  
Matthew R. Mumpower ◽  
...  
Keyword(s):  
Neutron Star ◽  
Solar System ◽  
Neutron Capture ◽  
Nuclear Physics ◽  
Early Solar System ◽  
Capture Process ◽  
Astrophysical Source ◽  
R Process ◽  
Process Elements

The composition of the early Solar System can be inferred from meteorites. Many elements heavier than iron were formed by the rapid neutron capture process (r-process), but the astrophysical sources where this occurred remain poorly understood. We demonstrate that the near-identical half-lives (≃15.6 million years) of the radioactive r-process nuclei iodine-129 and curium-247 preserve their ratio, irrespective of the time between production and incorporation into the Solar System. We constrain the last r-process source by comparing the measured meteoritic ratio 129I/247Cm = 438 ± 184 with nucleosynthesis calculations based on neutron star merger and magneto-rotational supernova simulations. Moderately neutron-rich conditions, often found in merger disk ejecta simulations, are most consistent with the meteoritic value. Uncertain nuclear physics data limit our confidence in this conclusion.

Osmium isotope evidence for uniform distribution of s- and r-process components in the early solar system

2007 ◽  
Vol 259 (3-4) ◽  
pp. 567-580 ◽  
Author(s):  
Tetsuya Yokoyama ◽  
Vinai K. Rai ◽  
Conel M. O'D. Alexander ◽  
Roy S. Lewis ◽  
Richard W. Carlson ◽  
...  
Keyword(s):  
Solar System ◽  
Uniform Distribution ◽  
Early Solar System ◽  
Isotope Evidence ◽  
R Process ◽  
Osmium Isotope

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

Preface: Evolution of the early solar system: Presolar cosmochemical fingerprints and the formation of watery rocky planets

2016 ◽  
Vol 50 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Tomohiro Usui ◽  
Audrey Bouvier ◽  
Justin I. Simon ◽  
Noriko Kita
Keyword(s):  
Solar System ◽  
Early Solar System ◽  
Rocky Planets

A nearby neutron-star merger explains the actinide abundances in the early Solar System

Nature ◽  
2019 ◽  
Vol 569 (7754) ◽  
pp. 85-88 ◽  
Author(s):  
Imre Bartos ◽  
Szabolcs Marka
Keyword(s):  
Neutron Star ◽  
Solar System ◽  
Early Solar System

OSIRIS-REx at Bennu: Overcoming challenges to collect a sample of the early Solar System

2021 ◽  
pp. 163-194
Author(s):  
Dante S. Lauretta ◽  
Heather L. Enos ◽  
Anjani T. Polit ◽  
Heather L. Roper ◽  
Catherine W.V. Wolner
Keyword(s):  
Solar System ◽  
Early Solar System

Exchange Frequency of Oxygen Isotope Reservoirs in The Early Solar System

2008 ◽  
Author(s):  
S. Itoh ◽  
H. Yurimoto ◽  
Takuma Suda ◽  
Takaya Nozawa ◽  
Akira Ohnishi ◽  
...  
Keyword(s):  
Solar System ◽  
Oxygen Isotope ◽  
Early Solar System ◽  
Exchange Frequency
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