Neutron-Capture Element Abundances in Planetary Nebulae

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.

arXiv comment9 pages, one figure, to appear in Proceedings of WORKPLANS II (Lorentz Center Workshop, Leiden, the Netherlands, December 2019), edited by T. Ueta, accepted for publication by Galaxies

References in corpus (22)

• X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope
• A kilonova as the electromagnetic counterpart to a gravitational-wave source
• The Emergence of a Lanthanide-Rich Kilonova Following the Merger of Two Neutron Stars
• Near-Field Cosmology with Metal-Poor Stars
• Identification of strontium in the merger of two neutron stars
• Rubidium-Rich Asymptotic Giant Branch Stars
• Nucleosynthesis Predictions for Intermediate-Mass AGB Stars: Comparison to Observations of Type I Planetary Nebulae
• Heavy-element yields and abundances of Asymptotic Giant Branch models with a Small Magellanic Cloud metallicity
• s-Process Abundances in Planetary Nebulae
• Rubidium, zirconium, and lithium production in intermediate-mass asymptotic giant branch stars
• Physical Properties of Fullerene-containing Galactic Planetary Nebulae
• Fluorine abundances in planetary nebulae
• S-process enrichment in the planetary nebula NGC 3918. Results from deep echelle spectrophotometry
• The detection of C60 in the well-characterized planetary nebula M1-11
• Discovery of Rubidium, Cadmium, and Germanium Emission Lines in the Near-Infrared Spectra of Planetary Nebulae
• Circumstellar effects on the Rb abundances in O-rich AGB stars
• Neutron-capture element abundances in the planetary nebula NGC 5315 from deep optical and near-infrared spectrophotometry
• The post-common-envelope binary central star of the planetary nebula ETHOS 1
• Characterisation of the Planetary Nebula Tc 1 Based on VLT X-Shooter Observations
• Physical properties of the fluorine and neutron-capture element-rich PN Jonckheere 900
• Fluorine production in intermediate-mass stars
• Chemical Abundances in the PN Wray16-423 in the Sagittarius Dwarf Spheroidal Galaxy: Constraining the Dust Composition