s-process Enrichment in the Planetary Nebula NGC 3918

TL;DR

This study provides detailed spectroscopic analysis of planetary nebula NGC 3918, detecting faint neutron-capture element lines to accurately determine s-process element abundances and improve understanding of nucleosynthesis.

Contribution

First deep, high-resolution UVES spectra of NGC 3918 identifying over 700 lines, including faint s-process element lines, enabling precise abundance measurements.

Findings

Detection of faint lines of Kr, Xe, and Rb.

Accurate chemical abundances of s-process elements.

Constraints on s-process efficiency and dredge-up processes.

Abstract

We present deep, high-resolution (R~40000) UVES at VLT spectrophotometric data of the planetary nebula NGC 3918. This is one of the deepest spectra ever taken of a planetary nebula. We have identified and measured more than 700 emission lines and, in particular, we have detected very faint lines of several neutron-capture elements (s-process elements: Kr, Xe and Rb) that enable us to compute their chemical abundances with unprecedented accuracy, thus constraining the efficiency of the s-process and convective dredge-up.