Neutron-Capture Element Abundances in Planetary Nebulae

TL;DR

This paper reviews recent advancements in nebular spectroscopy that improve the measurement of heavy element abundances in planetary nebulae, shedding light on s-process nucleosynthesis in various galaxies.

Contribution

It highlights new observational techniques and discoveries of neutron-capture elements in planetary nebulae, expanding understanding of stellar nucleosynthesis.

Findings

Detection of n-capture elements in PNe across different galaxies

Improved abundance measurements using near-infrared and optical spectroscopy

Identification of trends and open questions in s-process enrichment

Abstract

Nebular spectroscopy is a valuable tool for assessing the production of heavy elements by slow neutron(n)-capture nucleosynthesis (the s-process). Several transitions of n-capture elements have been identified in planetary nebulae (PNe) in the last few years, with the aid of sensitive high-resolution near-infrared spectrometers. Combined with optical spectroscopy, the newly discovered near-infrared lines enable more accurate abundance determinations than previously possible, and provide access to elements that had not previously been studied in PNe or their progenitors. Neutron-capture elements have also been detected in PNe in the Sagittarius Dwarf galaxy and in the Magellanic Clouds. In this brief review, I discuss developments in observational studies of s-process enrichments in PNe, with an emphasis on the last five years, and note some open questions and preliminary trends.