Summary

• GRB show mass-dependent obscuration
• Predicted by simulations
• Metallicity-effects
• Host galaxy obscuration for AGN population
• Caveats: SF distribution
• Galaxy-scale obscuration important at NH = 1022 – 1023 cm-2
• Fractions consistent with simulations
• Nuclear obscurer model for Torus modellers & simulations
• Covering factors is dependent on
• Black hole mass
• Accretion rate (X-ray luminosity)
• Host galaxy mass