On distinguishing age from metallicity with photometric data

TL;DR

This paper evaluates various photometric systems to determine their effectiveness in distinguishing galaxy age from metallicity, finding limited success mainly with Stromgren filters and noting reduced age sensitivity with updated models.

Contribution

It systematically assesses multiple photometric systems for age-metallicity disentanglement, highlighting the Stromgren system's moderate success and the impact of updated isochrones.

Findings

Stromgren [c_1] vs. [m_1] plot shows moderate age-metallicity separation.

Optical to near-infrared broad bands have decreased age sensitivity with new isochrones.

Most photometric systems tested do not effectively disentangle age and metallicity.

Abstract

In the study of galaxy integrated light, if photometric indicators could extract age and metallicity information of high enough quality, photometry might be vastly more efficient than spectroscopy for the same astrophysical goals. Toward this end, we search three photometric systems: David Dunlap Observatory (DDO), Beijing-Arizona-Taiwan-Connecticut (BATC), and Stromgren systems for their ability to disentangle age and abundance effects. Only the Stromgren [c_1] vs. [m_1] plot shows moderate age-metallicity disentanglement. We also add to the discussion of optical to near-infrared Johnson-Cousins broad band colours, finding a great decrease in age sensitivity when updated isochrones are used.