scholarly journals Silicon and Carbon Isotopic Ratios in AGB Stars: SiC Grain Data, Models, and the Galactic Evolution of the Si Isotopes

2006 ◽  
Vol 650 (1) ◽  
pp. 350-373 ◽  
Author(s):  
Ernst Zinner ◽  
Larry R. Nittler ◽  
Roberto Gallino ◽  
Amanda I. Karakas ◽  
Maria Lugaro ◽  
...  
Keyword(s):  
Data Models ◽  
Galactic Evolution ◽  
Isotopic Ratios ◽  
Agb Stars ◽  
Carbon Isotopic ◽  
Si Isotopes

Carbon and oxygen isotopes in AGB stars. From the cores of AGB stars to presolar dust

2018 ◽  
Vol 14 (S343) ◽  
pp. 447-448
Author(s):  
Thomas Lebzelter ◽  
Kenneth Hinkle ◽  
Oscar Straniero
Keyword(s):  
Solar System ◽  
Stellar Evolution ◽  
Galactic Evolution ◽  
Isotopic Ratios ◽  
Red Giants ◽  
Agb Stars ◽  
Carbon And Oxygen Isotopes ◽  
Different Types ◽  
Red Giant ◽  
Final Evolution

AbstractIsotopic ratios are a powerful tool for gaining insights into stellar evolution and nucleosynthesis. The isotopic ratios of the key elements carbon and oxygen are perfectly suited to investigate the pristine composition of red giants, the conditions in their interiors, and the mixing in their extended atmospheres. Of course the dust ejected from red giants in their final evolution also contains isotopically tagged material. This red giant dust is present in the solar system as presolar dust grains. We have measured isotopic ratios of carbon and oxygen in spectra from a large sample of AGB stars including both Miras and semiregular variables. We show how the derived ratios compare with expectations from stellar models and with measurements in presolar grains. Comparison of isotopes that are affected by different types of nucleosynthesis provides insights into galactic evolution.

The Galactic Evolution of Si, Ti, and O Isotopic Ratios

1999 ◽  
Vol 519 (1) ◽  
pp. 222-235 ◽  
Author(s):  
Conel M. O’D. Alexander ◽  
Larry R. Nittler
Keyword(s):  
Galactic Evolution ◽  
Isotopic Ratios

Galactic evolution of 7Li: the interplay between novae and AGB stars

2001 ◽  
Vol 688 (1-2) ◽  
pp. 442-446
Author(s):  
C. Travaglio ◽  
D. Galli ◽  
S. Randich
Keyword(s):  
Galactic Evolution ◽  
Agb Stars

scholarly journals The chronology of Jäkärlä Ware – Bayesian interpretation of the old and new radiocarbon dates from Early and Middle Neolithic southwest Finland

2019 ◽  
Vol 46 ◽  
pp. 246-267
Author(s):  
Petro Pesonen ◽  
Markku Oinonen
Keyword(s):  
Isotopic Ratios ◽  
Stable Carbon ◽  
Radiocarbon Dates ◽  
Reservoir Effect ◽  
Carbon Isotopic ◽  
Potential Reservoir

The chronology of the eastern Fennoscandian Neolithic is organized with the help of pottery styles, one of which is southwestern Finnish Jäkärlä Ware. In this paper a number of new radiocarbon dates connected with Jäkärlä Ware and other relevant ceramic groups are presented and discussed. The radiocarbon dates of each group are modelled within a Bayesian chronological framework. Also, the potential reservoir effect in charred crust dates is estimated for each date based on stable carbon isotopic ratios of the crust samples and incorporated into models. Jäkärlä Ware appears to be a short-living and quite a isolated group, which had no chronological contacts with Sperrings 1–2 Wares, but with possible coexistence with Middle Neolithic Typical Comb Ware. Jäkärlä Ware is partly simultaneous with eastern Finnish asbestos-tempered Kaunissaari Ware, and forms with it a short chronological horizon in the turn of the Early and Middle Neolithic of eastern Fennoscandia.

scholarly journals Peculiar J-type Carbon Stars and Li

2000 ◽  
Vol 198 ◽  
pp. 506-507
Author(s):  
S. Lorenz-Martins ◽  
N. A. Drake
Keyword(s):  
High Resolution ◽  
Spectral Region ◽  
Resonance Line ◽  
Spectral Synthesis ◽  
Synthesis Method ◽  
Isotopic Ratios ◽  
Carbon Stars ◽  
Carbon Isotopic ◽  
Carbon Abundance ◽  
Extended Range

We determined the carbon and lithium abundances and carbon isotopic ratios for 4 peculiar carbon stars by means of spectral synthesis method. Li abundances were derived using Li resonance line at λ6707.8 Â. For carbon abundance determinations we used the lines of the red system of CN molecule. Spectral region of λλ7994 — 8030 Â containing the lines of molecules 12CN and 13CN was used also for 12C/13C ratio measuring. The high-resolution spectra were obtained on the 1.52m telescope of ESO with the Fiber-fed Extended Range Optical Spectrograph (FEROS). These observations were obtained under the agreement between the CNPq-Observatório Nacional, Brazil, and ESO.

Carbon isotopic ratios of wetland and terrace soil sequences in the Maya Lowlands of Belize and Guatemala

CATENA ◽  
2011 ◽  
Vol 85 (2) ◽  
pp. 109-118 ◽  
Author(s):  
Timothy Beach ◽  
Sheryl Luzzadder-Beach ◽  
Richard Terry ◽  
Nicholas Dunning ◽  
Stephen Houston ◽  
...  
Keyword(s):  
Isotopic Ratios ◽  
Maya Lowlands ◽  
Carbon Isotopic
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