From the First Stars to the First Black Holes

We investigate the nature and origin of the first super-massive black holes at redshift larger than 5 by means of an improved version of the semi analytical model GAMETE/QSOdust. In this study, we model the formation of the progenitors (seeds) of the first super-massive black holes along host galaxies hierarchical assembly. Low-mass seed black holes (~100 Msun) form as remnants of massive (260-300 Msun), population III stars, the so-called light seeds, while intermediate mass black holes (10^4 - 10^5 Msun), the so-called heavy seeds, arise from the direct collapse of gas in metal poor (Z