Speaker
Description
Open clusters provide robust constraints on Galactic chemical evolution because their member stars have well defined ages, Galactic birth radii, and a shared chemical baseline. This homogeneity enables high precision constraints by averaging abundances across multiple stars within the same cluster, reducing the impact of star to star scatter and measurement uncertainties. However, the distribution of many key elements across the Galactic disc remains insufficiently characterised due to limitations of optical spectroscopy. High resolution infrared observations address this challenge by enabling access to diagnostics such as F and K, facilitating a more comprehensive and physically complete understanding of chemical enrichment.
In this talk, results will be presented from three recent papers in which stellar parameters and abundances were derived with PySME using an extensive diagnostic set of spectral lines, including OH, CN, and CO molecular features and atomic transitions such as Mg I, Si I, Ti I and Ti II, C I, and Fe I, ensuring internal consistency. Abundances for up to 23 elements, C, N, F, Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Ce, Nd, and Yb, were measured in 114 stars across 41 open clusters. NLTE corrections were applied to many key species and results were cross compared with literature where available. Trends in [X/Fe] and [X/H] versus metallicity, age, and Galactocentric radius show clear radial structure, with [X/Fe] gradients spanning −0.061 to +0.065 dex/kpc, supporting inside out disc growth and enrichment timescales that vary with radius. A major new result is the first infrared open cluster determination of radial abundance gradients for the heavy neutron capture elements Nd and Yb, providing new empirical leverage on neutron capture sources and heavy element enrichment across the Galactic disc.