In section 1. Letters
Observational evidence of quasar feedback quenching star formation at high redshift
Quasar feedback is frequently invoked to help explain how star formation is moderated, in particular at high redshift. However, evidence of this phenomenon is scarce. The authors have used the VLT-SINFONI spectroscopy of a luminous quasar at z=2.4 and find [OIII] emission that reveals a massive outflow and narrow Halpha emission revealing star formation. The Halpha emission is strongly suppressed in the [OIII] region, indicating that the quasar outflow has quenched the star formation, by removing the molecular gas.