To be published in the proceeding volume of Astrophysical Letters and Communications, 2000

Abstract. The total energy emitted by the growth of massive black holes is large and can be 10-50 per cent of that emitted by stars in the universe. I show how the X-ray Background provides a good measure of this energy and also why most accretion power is absorbed and re-emitted in the far infrared band. A model for the obscured growth of massive black holes is presented which accounts for both the high absorption and the observed black hole to galaxy spheroid mass correlation. Future missions should detect the obscured X-ray sources associated with the growth of massive black holes.

Table of Contents

INTRODUCTION

ACCRETION AND THE XRB

AGN, THE FIR BACKGROUND AND THE ENERGY FROM STARS

UNCERTAINTIES

OBSCURATION, METALLICITY AND FUELLING

THE MEAN LUMINOSITY OF THE DISTANT AGN DOMINATING THE XRB INTENSITY

OBSCURATION IN A GROWING, ISOTHERMAL GALAXY SPHEROID

REFERENCES