Elemental abundances in the center of the Galactic Nuclear Disc

TL;DR

This study investigates the chemical composition of the Galactic Nuclear Disc using high-resolution infrared spectroscopy of Cepheids, revealing a radial abundance pattern with a peak around 2-4 kpc from the center.

Contribution

First detailed chemical analysis of stars within 1 kpc of the Galactic center, extending understanding of the Galactic abundance gradient.

Findings

Elemental abundances near solar levels in central stars.

Iron abundance peaks at 2-4 kpc from the Galactic center.

Abundance declines sharply towards the center.

Abstract

We have made the first attempt to derive the chemical properties of the Galactic disc at its very central part using high-resolution infrared spectroscopic observations of four classical Cepheids. Those stars are located at Galactocentric distances smaller than 1 kpc. All investigated stars show near-to-solar elemental abundances. By combining these new data with our previous studies, this result suggests that the radial distribution of iron abundance on a logarithmic scale gradually increases from the outskirts of the Galactic disc to Galactocentric distances of about 2-4 kpc, reaching there a maximal value of about +0.4 dex, and then declines sharply to about the solar value at the Galactic Center.