# Open clusters in APOGEE and GALAH: Combining Gaia and ground-based spectroscopic surveys

## TL;DR

This study combines Gaia data with APOGEE and GALAH spectroscopic surveys to determine radial velocities and chemical abundances for numerous open clusters, significantly expanding the available high-resolution spectroscopic data for these stellar systems.

## Contribution

It provides the first high-resolution spectroscopic radial velocities for 16 open clusters and new chemical abundance measurements for many clusters previously lacking such data.

## Key findings

- Radial velocities determined for 131 (APOGEE) and 14 (GALAH) clusters.
- Chemical abundances obtained for 90 (APOGEE) and 14 (GALAH) clusters.
- 66 clusters have new data not previously available in literature.

## Abstract

Context: Open clusters are ideal laboratories to investigate a variety of astrophysical topics, from the properties of the Galactic disk to stellar evolutionary models. Knowing their metallicity and possibly detailed chemical abundances is therefore important. However, the number of systems with chemical abundances determined from high resolution spectroscopy is still small.\\ Aims: To increase the number of open clusters with radial velocities and chemical abundances determined from high resolution spectroscopy we used publicly available catalogues of surveys in combination with Gaia data.\\ Methods: Open cluster stars have been identified in the APOGEE and GALAH spectroscopic surveys by cross-matching their latest data releases with stars for which high-probability astrometric membership has been derived in many clusters on the basis of the Gaia second data release.\\ Results: Radial velocities have been determined for 131 and 14 clusters from APOGEE and GALAH data, respectively. This is the first radial velocity determination from high resolution spectra for 16 systems. Iron abundances have been obtained for 90 and 14 systems from APOGEE and GALAH samples, respectively. To our knowledge 66 of these clusters (57 in APOGEE and 9 in GALAH) do not have previous determinations in the literature. For 90 and 7 clusters in the APOGEE and GALAH samples, respectively, we have also determined average abundances for Na, Mg, Al, Si, Ca, Cr, Mn, and Ni.