Metallicity of RUBIES-UDS-QG-z7

Ascertain the stellar metallicity Z∗ of the massive quiescent galaxy RUBIES-UDS-QG-z7 using higher signal-to-noise spectroscopy and/or stellar population models that incorporate non-solar abundance patterns, to resolve the current inability to constrain Z∗ accurately.

Background

The paper obtains similarly good SED fits for low (≲0.1 Z⊙) and high (≳ Z⊙) metallicities, likely due to limitations of current spectral models (e.g., lack of α-enhanced templates) and the available low-resolution data. This leaves the metallicity of RUBIES-UDS-QG-z7 unresolved, with implications for interpreting its formation history and chemical enrichment.