Low redshift AGN in the Hamburg/ESO Survey: II. The active black hole mass function and the distribution function of Eddington ratios

Understand

We estimated black hole masses and Eddington ratios for a well defined sample of local (z<0.3) broad line AGN from the Hamburg/ESO Survey (HES), based on the Hbeta line and standard recipes assuming virial equilibrium for the broad line region.

• The sample represents the low-redshift AGN population over a wide range of luminosities, from Seyfert 1 galaxies to luminous quasars.
• From the distribution of black hole masses we derived the active black hole mass function (BHMF) and the Eddington ratio distribution function (ERDF) in the local universe, exploiting the fact that the HES has a well-defined selection function.
• While the directly determined ERDF turns over around L/L_Edd ~ 0.1, similar to what has been seen in previous analyses, we argue that this is an artefact of the sample selection.