SMBH growth, previous results

• Previous comparisons of the local BH relic mass density with that inferred from AGN activity

• Fabian & Iwasawa (1999) found consistency between XRB and local BH mass density: No need for significant low-efficiency accretion

• Elvis, Risaliti & Zamorani (2002) compared XRB with local BH mass density using a more sophisticated bolometric correction: Need for high efficiency >0.15

• Yu & Tremaine (2002) compared local BH mass function with QSO LF evolution (from 2dF): Need high efficiency (>0.1) for high luminosity objects

• Marconi et al. (2004) compared local BH mass function with hard X-ray selected AGN LF: 0.16>>0.04

• Note that when comparing local and accreted mass functions, an assumption is made about the Eddington-scaled accretion rate