Chemical abundances of planetary nebulae in the disk-bulge connection

TL;DR

This study investigates the chemical abundances of planetary nebulae at the disk-bulge interface of the Milky Way to identify the galactocentric distance separating bulge and disk properties, finding it to be around 2.9 kpc.

Contribution

It provides new abundance measurements for planetary nebulae in the disk-bulge region and determines the galactocentric distance that best separates bulge and disk chemical properties.

Findings

Chemical abundance distribution similar to bulge stars.

Inner limit of the disk at approximately 2.9 kpc.

Statistical analysis supports the separation distance.

Abstract

We report the spectrophotometric investigation of a planetary nebula sample located at the disk-bulge interface of the Milky Way. The main goal of this work was to determine the galactocentric distance where, according to the intermediate mass population, bulge and disk properties separate. In order to derive such distance, new abundances were derived for a sample of PN located at this region, and the results were combined with additional data from the literature. The abundance analysis indicates a chemical abundance distribution similar to that derived from bulge stars, as already pointed out by other authors. Statistical distance scales were then used to study the distribution of chemical abundances across the disk-bulge connection. A Kolmogorov-Smirnov test was used to find the distance in which the chemical properties of these regions better separate, resulting in a best value of 2.9 kpc to define the inner limit of the disk.