The Millennium Galaxy Catalogue: the Mbh– Lspheroid derived supermassive black hole mass function.

Supermassive black hole (SMBH) mass estimates are derived for 1743 galaxies from the Millennium Galaxy Catalogue (MGC) using the recently revised empirical relation between SMBH mass and the luminosity of the host spheroid. The MGC spheroid luminosities are based on bulge plus exponential-disc decompositions. The majority of black hole masses reside between and an upper limit of . Using previously determined space-density weights, we derive the SMBH mass function which we fit with a Schechter-like function. Integrating the black hole mass function over gives an SMBH mass density of ( for early-type galaxies and ( for late-type galaxies. The errors are estimated from Monte Carlo simulations which include the uncertainties in the relation, the luminosity of the host spheroid and the intrinsic scatter of the relation. Assuming SMBHs form via baryonic accretion, we find that ( per cent of the Universe's baryons are currently locked up in SMBHs. This result is consistent with our previous estimate based on the (Sérsic index) relation. [ABSTRACT FROM AUTHOR]