Empirical Relationship Between Calcium Triplet Equivalent Widths and Stellar Metallicity

An empirical relationship for red giant branch stars linking overall metallicity to the sum of equivalent widths of near-infrared calcium triplet spectral lines. The method uses Gaia mission photometry and astrometry, and archival spectra from 2050 red giant branch stars across 18 globular clusters. It was authored by Jeffrey D. Simpson of UNSW Sydney.

Use Cases

• Calibrating metallicity measurements for red giant stars based on calcium triplet equivalent widths.
• Validating stellar population models using empirical relationships derived from globular cluster data.
• Estimating the metallicity of field stars using Gaia photometry and the derived empirical calibration.

Strengths

• The dataset is based on spectra from 2050 red giant branch stars.
• It covers stars from 18 distinct globular clusters, providing a range of metallicity environments.
• The method leverages the all-sky coverage and precision of the Gaia mission.

Limitations

• The specific number of rows and columns is unknown, making scale and feature assessment difficult.
• Column-level documentation is absent; field semantics must be inferred after download.
• The last update date is unknown; freshness is unverified.

Provenance

Source

Jeffrey D. Simpson, UNSW Sydney

Collection Method

Analysis of archival spectra from the Anglo-Australian Telescope's AAOmega spectrograph combined with Gaia photometry.

Geography

All-sky (via Gaia), with specific data from 18 globular clusters.