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Cosmic Backgrounds from Miniquasars

R. Salvaterra·F. Haardt·A. Ferrara
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Abstract

A large population of Intermediate Mass Black Holes (IMBHs) might be produced at early cosmic times as a left over of the evolution of the very massive first stars. Accretion onto IMBHs provides a source of (re)ionizing radiation. We show that the baryon mass fraction locked into IMBHs and their growth is strongly constrained by the observed residual Soft X-ray Background (SXRB) intensity. Thus, unless they are extremely X-ray quiet, miniquasars must be quite rare and/or have a short shining phase. As a byproduct, we find that miniquasars can not be the only source of reionization and that their alleged contribution to the near infrared bands is completely negligible.

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R. Salvaterra, F. Haardt, A. Ferrara. 2005-07-08. Cosmic Backgrounds from Miniquasars. https://doi.org/10.1111/j.1745-3933.2005.00074.x

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