An estimate of the time variation of the abundance gradient from planetary nebulae III. O, S, Ar, and Ne: A comparison of PN samples

TL;DR

This study analyzes planetary nebulae samples to investigate how the radial abundance gradients of oxygen, sulfur, argon, and neon in the galactic disk have evolved over the last 6 to 8 billion years, indicating a flattening trend.

Contribution

It provides a comparative analysis of multiple planetary nebulae samples to assess the time variation of abundance gradients for four key elements in the galactic disk.

Findings

Radial abundance gradients have flattened over the last 6-8 Gyr.

Analysis supports earlier conclusions of gradient flattening.

Multiple samples confirm the trend across different data sets.

Abstract

The time behaviour of the radial abundance gradients in the galactic disk is investigated on the basis of four different samples of planetary nebulae, comprising both smaller, homogeneous sets of data, and larger, albeit non-homogeneous samples. Four different chemical elements are considered, namely, oxygen, sulphur, argon and neon. Our analysis support our earlier conclusions that, on the average, the radial abundance gradients have flattened out in the last 6 to 8 Gyr.