The SEGUE Stellar Parameter Pipeline. IV. Validation with an Extended Sample of Galactic Globular and Open Clusters

TL;DR

This paper validates the SEGUE Stellar Parameter Pipeline's ability to accurately determine metallicities and radial velocities of stars in globular and open clusters, showing it performs well across different metallicity ranges.

Contribution

The paper presents an extended validation of the SSPP with new cluster data, demonstrating improved accuracy and confidence in its stellar parameter estimates.

Findings

Mean metallicity estimates are within 2σ of literature values.

Mean radial velocities agree within 1σ of literature values.

Pipeline improvements enhance accuracy at metallicity extremes.

Abstract

Spectroscopic and photometric data for likely member stars of five Galactic globular clusters (M3, M53, M71, M92, and NGC 5053) and three open clusters (M35, NGC 2158, and NGC 6791) are processed by the current version of the SEGUE Stellar Parameter Pipeline (SSPP), in order to determine estimates of metallicities and radial velocities for the clusters. These results are then compared to values from the literature. We find that the mean metallicity (<[Fe/H]>) and mean radial velocity (<RV>) estimates for each cluster are almost all within 2{\sigma} of the adopted literature values; most are within 1{\sigma}. We also demonstrate that the new version of the SSPP achieves small, but noteworthy, improvements in <[Fe/H]> estimates at the extrema of the cluster metallicity range, as compared to a previous version of the pipeline software. These results provide additional confidence in the application of the SSPP for studies of the abundances and kinematics of stellar populations in the Galaxy.