Caveats

• Geometric effects from different POV
• but <x1.5 for ellipsoidal geometries
• Relation from actively star-forming galaxies
• AGN have typical/lower SFR, also red&dead ell.
• Metallicity lower in GRB than AGN hosts
• but overlap
• AGN feedback may alter galaxies
• outflows, radiation pressure
• Massive AGN host galaxies with NH<10²² cm-2 exist
• e.g. BCG; – ionisation; rare