Quasar Metal Abundance and FIR Luminosity

TL;DR

This study investigates the relationship between quasar metallicities and host galaxy star formation rates at high redshift, revealing early star formation activity prior to the quasar phase but no correlation with current SFR.

Contribution

It provides new insights into the timing of star formation relative to quasar activity by comparing metallicities and FIR luminosities in high-redshift quasars.

Findings

High metallicities up to several times solar are observed.

No correlation between metallicity and current star formation rate.

Star formation began before the visible quasar phase.

Abstract

We compare the metallicities in high-redshift quasars to the star formation rates (SFR) in their host galaxies using measurements of broad emission lines and far-infrared (FIR) luminosities. The FIR emission indicates the level of ongoing massive starbursts in the galaxy, whereas the abundance of metals in the gas surrounding the quasar indicates the amount of star formation which occurred before the visible quasar phase began. The results of this study can be used to constrain the late stages of starburst-quasar evolution. We detect high metallicities throughout the sample, up to several times solar, confirming that star formation must have begun before the visible quasar phase. However, we do not detect a trend in metallicity versus current SFR.