Atomic Data and Neutron-Capture Element Abundances in Planetary Nebulae
نویسندگان
چکیده
منابع مشابه
Improved Neutron-Capture Element Abundances in Planetary Nebulae
Spectroscopy of planetary nebulae (PNe) provides the means to investigate s-process enrichments of neutron(n)-capture elements that cannot be detected in asymptotic giant branch (AGB) stars. However, accurate abundance determinations of these elements present a challenge. Corrections for unobserved ions can be large and uncertain, since in many PNe only one ion of a given n-capture element has ...
متن کاملThe Abundances of Light Neutron-Capture Elements in Planetary Nebulae
We present preliminary results from a large-scale survey of the neutron(n)-capture elements Se and Kr in Galactic planetary nebulae (PNe). These elements may be produced in PN progenitors by s-process nucleosynthesis, and brought to the stellar envelope by third dredge-up (TDU). We have searched for [Kr III] 2.199 and [Se IV] 2.287 μm in 120 PNe, and detected one or both lines in 79 objects, fo...
متن کاملA Large-Scale Survey of Neutron-Capture Element Abundances in Planetary Nebulae
We present results from the first large-scale survey of neutron(n)capture element abundances in planetary nebulae (PNe). This survey was motivated by the fact that a PN may be enriched in n-capture elements if its progenitor star experienced s-process nucleosynthesis during the thermally-pulsing asymptotic giant branch (AGB) phase. We have measured emission from Se and Kr in over 100 PNe, and u...
متن کاملThe Abundances of Light Neutron-Capture Elements in Planetary Nebulae – I. Photoionization Modeling and Ionization Corrections
We have conducted a large-scale survey of 120 planetary nebulae (PNe) to search for the near-infrared emission lines [Kr III] 2.199 and [Se IV] 2.287 μm. The neutron(n)-capture elements Se and Kr may be enriched in a PN if its progenitor star experienced s-process nucleosynthesis and third dredge-up. In order to determine Se and Kr abundances, we have added these elements to the atomic database...
متن کاملNeutron-Capture Element Abundances and Cosmochronometry
Abundance ratios of radioactive to stable neutron-capture elements in very metal-poor stars may be used to estimate the age of our Galaxy. But extracting accurate ages from these data requires continuing work on many fronts: a) identification of more low metallicity stars with neutron-capture element excesses; b) acquisition of the best high resolution stellar spectra; c) improvement in neutron...
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ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2016
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s174392131700062x