Black Hole Demography: From scaling relations to models

TL;DR

This paper reviews current knowledge on local black hole scaling relations, their uncertainties, and how they inform models of black hole demographics and evolution in galaxies.

Contribution

It synthesizes observational evidence and discusses the implications of uncertainties and different evolutionary models for black hole demography.

Findings

Systematic uncertainties affect black hole mass function estimates.

Evidence suggests different evolution for separate BH-galaxy scaling relations.

Constraints on evolutionary models of black hole growth.

Abstract

In this contributed paper I review our current knowledge of the local Black Hole (BH) scaling relations, and their impact on the determination of the local BH mass function. I particularly emphasize the remaining systematic uncertainties impinging upon a secure determination of the BH mass function and how progress can be made. I then review and discuss the evidence for a different time evolution for separate BH-galaxy scaling relations, and how these independent empirical evidences can be reconciled with the overall evolution of the structural properties of the host galaxies. I conclude discussing BH demography in the context of semi-empirical continuity accretion models, as well as more complex evolutionary models, emphasizing the general constraints we can set on them.