Heating of the intergalactic medium by primordial miniquasars

Saleem Zaroubi*, Rajat M. Thomas, Naoshi Sugiyama, Joseph Silk

*Bijbehorende auteur voor dit werk

Onderzoeksoutput: ArticleAcademicpeer review

43 Citaten (Scopus)
153 Downloads (Pure)


A simple analytical model is used to calculate the X-ray heating of the intergalactic medium (IGM) for a range of black hole masses. This process is efficient enough to decouple the spin temperature of the IGM from the cosmic microwave background (CMB) temperature and produce a differential brightness temperature of the order of similar to 5-20 mK out to distances as large as a few comoving Mpc, depending on the redshift, black hole mass and lifetime. We explore the influence of two types of black holes, those with and without ionizing ultraviolet radiation. The results of the simple analytical model are compared to those of a full spherically symmetric radiative transfer code. Two simple scenarios are proposed for the formation and evolution of black hole mass density in the Universe. The first considers an intermediate mass black hole that form as an end-product of pop III stars, whereas the second considers supermassive black holes that form directly through the collapse of massive haloes with low spin parameter. These scenarios are shown not to violate any of the observational constraints, yet produce enough X-ray photons to decouple the spin temperature from that of the CMB. This is an important issue for future high-redshift 21-cm observations.

Originele taal-2English
Pagina's (van-tot)1269-1279
Aantal pagina's11
TijdschriftMonthly Notices of the Royal Astronomical Society
Nummer van het tijdschrift4
StatusPublished - 11-mrt.-2007

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